Buying a diesel car these days

Anything else to consider in petrol vs Diesel?

The old diesels' prefer to be used on longer journeys rather than fewer shorter ones still stands.

In before the inevitable 😀

DPF and ad-blue issues would worry me. I know a few people that have had ad-blue systems fail (VW-Audi)

I dont think ive much more to add beyond how and where are you planning on using it and going from that.

I'd just buy petrol if you aren't doing mega miles.

If we try hard we can get as much as 60mpg from our 2l petrol non turbo Mazda 3 but I still went and bought a diesel V40 which has turned out to be a mistake despite being about 10 to 20% more economical overall.

how and where are you planning on using it

20/40/60 mile journeys, plus occasional hoof down South (260 miles each way) - with the latter being main reason for diesel. Will be inevitable shorter journeys too, but also have a 1l petrol Polo for that.

Is Ad Blue a requirement since the 2014 engine in the Honda?

EDIT: I'm thinking this is probably the sensible approach:

I’d just buy petrol if you aren’t doing mega miles.

In different ways Petrol & Diesel both emit pollutants, morally you're best choosing the one that'll be used in the correct circumstances to minimise environmental pollution in balance with your financial circumstances.

Expect VED to creep up as we are incentivised to move to electric vehicles.

I would look at hybrid petrol, something like a corrolla estate as a mid-sized estate car. Real world av mpg is reported as 62.9 for the 1.8l . Obvs those sort of figures will be submitted by super-keen types, but useful as a comparison.

That's the sort of thing I will look into once I sell my van as I also need something ulez compliant nowadays.

1.5 petrol Passat which was less economical (using mpg as the measure)

Our 1.4tsi Leon gets same mpg's as the Volvo and Galaxy (@45mpg average, 50-54 on a long run). A smaller 1.6 diesel on a smaller car would of course do better. I think the Passat is a heavy and larger car than the Civic - may be worth looking more at a Golf sized petrol. FWIW, I would have bought the Kia Ceed estate instead of our Leon, but mrs_oab preferred the Leon.

But, what we have already noted is that servicing was cheaper and our other petrol car has also shown this AND has much less to repair than any of our diesels have.

Diesel is the same price as petrol these days, does better mpg. Just make sure its ULEZ compliant.

Modern turbo petrols can deliver pretty decent mpg these days, and all the pollution control stuff on a euro6+ diesel seem prone to issues.

As said, worth looking at hybrids, or PHEVs if you can plug in at home - your usage profile would suit it. Used to have a Golf GTE that was good for the general running about, could get 20 miles out of a charge but for something like the 100 mile round trip to the office it would do it on £1 of electric then about 70mpg equivalent (all the slow traffic that's usually bad for MPG you use the battery). Absolute worst case, long motorway trip starting on empty battery it would still do 42mpg.

The old diesels’ prefer to be used on longer journeys rather than fewer shorter ones still stands.

Not exactly accurate. Shorter journeys are ok - it's ONLY short journeys that are a problem.

The OP's usage sounds fine for diesel.

DPFs don't go wrong, they get blocked up if something else goes wrong and even then you should get a light. Ad blue systems can go wrong like anything else but aren't especially prone afaik and they actually allow the engine to run better than a non-ad blue engine as I understand it. On some cars ad blue is so effective they produce less NOx pollution than petrols.

Also, modern direct injection petrols are great to drive but they aren't without their issues, such as inlet valves gumming up.

Modern turbo petrols can deliver pretty decent mpg these days

But only if you drive like a granny keeping them out of the turbo zone / dont put much load through the engine

I got a 2 litre diesel Leon estate about 3 years ago.
I looked at electric cars, but there were a lot fewer options then, so decided against them pretty quick.
Petrol - looked into them, but seemed that a diesel would be the more sensible choice given the type of journeys I do.

I'm happy with the decision, although if making it today it would be a bit more difficult as there are many more electric cars on the road & second hand options too.
I get a long-term mpg of around 62mpg. On individual journeys it can be a lot higher than that, and obviously the shorter journey drag it down.
My Wife has a 2012 Ibiza also with a 2 litre diesel. That's on over 140k miles and we've had no issues with it. Cam belt was done in November, but apart from that....struggling to thing of anything that's needed doing besides brakes & standard servicing. Until recently, for about 3 years she worked <2 miles down the road & despite my gentle nudging that she should either walk or cycle she never did. It did worry me that the car was gonna protest, but it was never a problem. I guess there were enough longer distance journeys thrown in to keep the dpf clean & things running smoothly.

Neither of our cars run adblue.

Pretty sure you won't need ad blue in Honda. Our hrv 2016 doesn't need it and Honda engineer rather than chuck in supplements. Well that's my theory anyway.

Adblue is engineering. Nitrous oxides are inherent to the way diesel works, because the cylinder is always full of air but under part load only some of the oxygen is used up. So when combustion happens the cylinder gets really hot and the rest of the oxygen reacts with the nitrogen. So manufacturers invented EGR which pipes some exhaust gas back to the intake under part load which reduces the amount of available oxygen. This, as we know, can cause other issues. However SCR removes NOx directly from the exhaust so in theory you can run with less EGR and it can still get rid of the NOx (well, at least the nasty kinds). Honda aren't exempt from this.

As above, wouldn't consider a diesel unless I was doing 12k+ of mostly motorway miles imo.

DPF's, EGR valves, Ad-Blue systems are all extra systems that can fail, even if it can be largely mitigated if driving mostly motorway miles. Often slighty higher servicing fees too ime.

My 1.5t Leon's engine gets 50-55 mpg in flowing traffic and 250 nm of torque makes it surprinsgly grunty at low revs for a petrol (believe as it has a supplementarty supercharger).

So yeah, can recommend a leon estate, but not too sure I'd go diesel in this climate unless I was doing large miles.

Taken from https://www.thecarexpert.co.uk/honda-civic-diesel-review/

So the engine then. Trying to keep CO2 emissions down, while also reducing the NOx particulates that are causing the current urban air quality concerns, would normally mean increased fuel consumption. So Honda put its engineers to work.

A host of technical innovations include forged steel pistons instead of aluminium to reduce cooling losses, and several friction-reducing technologies to cut friction losses to levels normally only seen in petrol engines.

All this means combined cycle fuel economy of 80.1mpg and CO2 emissions of just 93g/km – seriously impressive, and achieved without having to get involved in any additives such as AdBlue.

- I call that better engineering.

Regardless of whether it's better engineering or not, I'm happy with a 2014 MINI Cooper SD. 2ltr BMW-sourced N47 euro6-compliant diesel with no need for AdBlue. 106g/km, 170bhp/266lbft and real-world heavyish-right-foot 60mpg (official combined 70.6mpg). I'd say that's impressive given the performance on offer.

As to the OP, I don't think there's much more to consider in petrol vs diesel. I wanted/needed something with low purchase prce and low running costs, and with a bit of poke. The equivalent petrol MINI was higher for both initial (used) purchase and running costs. If I needed next car size up then a diesel Golf would be on my radar.

I call that better engineering.

I call it advertising. How exactly did they solve the problem of NOx emissions (which are not particulates) without SCR? Never mind how efficient it is.

SCR/Ad Blue isn't a bodge. The alternative, EGR, is a bodge, SCR is the proper solution to the problem.

Whats all the concern about Ad Blue? Ive done about 30k miles and had to put Ad Blue in twice, didnt even had to leave my drive to add it to the car

Just bought an Ad-Blue requiring diesel V6. The Halfords 5L bags make for an easy refill on the drive. It's not an issue. We had a brand new petrol V6 loan car from the garage. Not even close in terms of drive and performance. Our 2009 CRV diesel is not ULEZ compliant. I didn't want another diesel, nor another SUV, but after driving it, I was sold. Pleased with the decision. and the engine is since discontinued. Next one will be petrol/hybrid, probably in about 3 years time.

would look at hybrid petrol, something like a corrolla estate as a mid-sized estate car

I wouldn't. We did. Guess where they put the battery? In the boot, significantly reducing load space making dog carriage a challenge for us. And EVERYONE will think you are driving a taxi. So choose a white one 😉

This is going to be one of those unhelpful comments but:

Will be inevitable shorter journeys too, but also have a 1l petrol Polo for that.

Do you really need two cars? Having a "long distance" car and a "short distance" car can't make any financial or environmental sense, surely?

If your household needs to use two cars at the same time, then fair enough...

Do you really need two cars? Having a “long distance” car and a “short distance” car can’t make any financial or environmental sense, surely?

We've thought about this a lot. We have that situation, a long distance and a short distance car. The latter will be electric (as of tomorrow hopefully) and the long distance is diesel.

We don't *really* need two, although it is helpful at times. Problem is that we do like to drag a shed on holidays sometimes, and EVs to do that are too expensive for our pocket. But we also want EV for the local travel because it's so much cheaper and can use renewable energy. Plus, the diesel may not like the relatively short trips which may hasten its demise. If it is only used for long jaunts and holidays then it will do 4-5k a year and probably last ages even though it's already ten years old. That said, it still has finance and we are paying a lot of money for those holidays and jaunts. But, if we were to get rid we'd have to find alternative arrangements for holidays which would cost us far more than our shed based vacations and be more stressful. Owning the diesel isn't necessarily going to result in a worse environmental footprint because if we sold it, another car would pop out of the bottom of the chain and be scrapped. By using it this way we are preserving it essentially.

The EV pays for half of itself in fuel savings too. Of course if you are not using an EV for local trips then the calculation is different but it still potentially preserves a more expensive car that would be better suited to long trips and worse suited for short ones.

Now, if having one car would force some trips to be made by bike, then it's a different story. That's not really the case for us, since I WFH and local shopping trips are done on foot.

Just get the newest Honda with the 1.6 diesel.  That engine is amazing.

Do you really need two cars?

Honestly, probably not. And despite the thread I'm trying my best not to be suckered into buying a second car. They sit on the driveway 90% of the time unused and I always wanted to sell one but someone has other ideas with the "what if we need two cars one day??!!". So I'm glad we've been forced into the situation where we can see whether we actually will need 2 rather than live in fear of it.

However, I asked because I'm trying to decide what I would buy, should it come to it.

e-bike 🙂

We were all set to go to one car, but our diesel is huge and parking is a serious issue where she works. Then the fuel cost is so much higher than EV that the extra cost of a second car becomes much lower, so then you think well it's "only" another £150/mo and so it goes.

I keep looking at PHEV petrol estates as the electric range would cover all our local usage and can charge from solar. That worked mean only needing fuel for longer trips. I can't make the numbers work though Vs a diesel. They are heavier and more expensive, less boot space and once the battery is flat seems like you loose the power/torque boost so they become slow and inefficient. None of manufacturers seem to indicate how much they regenerate while driving which suggests not much. Much as I don't want to I'm leaning towards another diesel and keeping it long term (till 10yrs oldish like the current one) then seeing how the market has changed. We already have a small EV for 90% of the local trips just weighs have been nice to not be outputting any pollution while moving around the city.

Do you really need two cars? Having a “long distance” car and a “short distance” car can’t make any financial or environmental sense, surely?

I didn't expect any scenario where it'd work out better financially and environmentally to have two vehicles rather than one, but mine comes close.

For my particular use it's financially better to run two vehicles. It's still two vehicles rather than one so not clearly environmental sense, but I consume a lot less fossil fuel by splitting my driving between a van (33mpg) and small diesel car (60mpg).

The saving in fuel by not using the van 100% of the time more than covers the running costs for the second vehicle (fuel, VED, MOT, consumables, insurance, servicing), with a comfortable surplus towards deprecation and unknowns. I didn't expect that.

The Toyota Corolla Est Phev sounds perfect for your needs, but boy are they dull. Anything with the 1.4 or 1.5TSI VAG engine will see 50+mpg on a long run, and the Golf Est in particular, is a very nice car indeed. Also the smaller output BMW petrol engines are very good on a long run.

Golf Est in particular

Other than the much hated touch screen UI on the Mk8. On this front I more tempted to see how it is improved for the incoming Mk8.5 facelift.

They are heavier and more expensive, less boot space and once the battery is flat seems like you loose the power/torque boost so they become slow and inefficient.

Hmm, not necessarily if you are aware of it. I think that some cars by default assume you want to recharge the battery from the engine once it's depleted, and some drivers don't bother to check the settings. However I think that you should be able to stop it doing that. As for slow - the Passat I was looking at has a 2.0 turbo petrol so not slow on petrol alone.

However I think that you should be able to stop it doing that. As for slow – the Passat I was looking at has a 2.0 turbo petrol so not slow on petrol alone.

I had a first generation BMW 3 series hybrid, and one of the things that really annoyed me was that you couldnt stop the engine re charging the battery which made mpg drop off a cliff. Also after 5 years of ownership the battery range went from about 20 miles to 5 miles.

I wouldnt buy a hybrid again unless it had functionality to turn re gen off. Actually I dont think I would buy a hybrid anyhow as they are being phased out.

Ive just googled and I cant even find replacement battery packs for it (new)

Do you really need two cars? Having a “long distance” car and a “short distance” car can’t make any financial or environmental sense, surely?

We have exactly this - Electric Mini used for most journeys, diesel Camper Van for long trips and things like ikea trips! Looked at if hiring was a better option but it made no sense financially to us. Van costs us very little in the big scheme of things.

All this means combined cycle fuel economy of 80.1mpg and CO2 emissions of just 93g/km – seriously impressive, and achieved without having to get involved in any additives such as AdBlue.

– I call that better engineering.

It's good engineering, but still doesn't 100% solve the problem in the real world. Customers don't drive like the emissions cycle. SCR works all the time, whether you are on cycle or off. Honda's system doesn't. So Honda solves something like 75% of the emissions solution, SCR is better (90% Maybe?). It's not a robust solution, but it probably is cheaper and definitely easier to look after.

They are heavier and more expensive, less boot space and once the battery is flat seems like you loose the power/torque boost so they become slow and inefficient.

Tell me you've not driven a hybrid without... you know the rest. The extra torque and power is there all the time, the battery is never "empty" in a PHEV. It might not have enough leccy in it to drive on electrical power, but unless it's broken, old or incredibly outdated (or designed by an idiot), the electrical drive will *almost* always provide power.

None of manufacturers seem to indicate how much they regenerate while driving which suggests not much.

Depends on the car architecture. And the battery chemistry, and how new it is.

Old ones don't regenerate much, new ones might turn well over 50% of the braking energy into electricity. The limiting factor in current/latest gen cars is either stability control (as the electric motor is on the rear axle, so you're limited by that) or that the battery physically cannot be charged any faster so you have to switch over to friction brakes.

some cars by default assume you want to recharge the battery from the engine once it’s depleted

On longer trips I'd absolutely want to do that. Given the performance figures will be quoted including (in VAG's case the 70ish BHP) electric motor. Ideally would want to recharge it using regenerative braking unless it got very low.

Passat I was looking at has a 2.0 turbo petrol so not slow on petrol alone.

As a PHEV? I've been looking lots at Passats and only seen the 1.4TSI as a PHEV. The wiki page does not list a 2 TSI hybrid. ( https://en.wikipedia.org/wiki/Volkswagen_Passat_(B8)). The GTE is a 148BHP 1.4TSI + 85Kw elec motor. Tdis model kind of proves the point, when the battery is dead you are left with 148Bhp in a 2 tonne car. Slow may be unfair but sluggish certainly isn't.

The extra torque and power is there all the time, the battery is never “empty” in a PHEV. It might not have enough leccy in it to drive on electrical power, but unless it’s broken, old or incredibly outdated, the electrical drive will *almost* always provide power.

That is what I'd hope. Getting confirmation it is the case however not so easy, my experience so far is the sales people have not got a clue.

I've not driven a hybrid with the hybrid parts not there as it were. Not a easy situation to manufacture on a short test drive :D. I have driven estates with the same power to weight ratio as the ones I'm looking at would be if electrical power was exhausted and that is not somewhere I'd like to be.

FunkyDunc
Free Member

Ive done about 30k miles and had to put Ad Blue in twice

Presumably a pre-dieselgate car?

Ideally would want to recharge it using regenerative braking unless it got very low.

But regen braking isnt 'free' energy you have spent energy and then can just recover a fraction of that energy so its not going to ever re charge a battery in any shape or form, just recoup some otherwise energy lost through heat friction.

Presumably a pre-dieselgate car?

Dunno - its a 2019 diesel Merc E Class

Yes I get that. I think there is a fair amount to reclaim, a decent slowing/braking event event at motorway speeds in our Zoe can add several miles to the guessometer.

As a PHEV? I’ve been looking lots at Passats and only seen the 1.4TSI as a PHEV. The wiki page does not list a 2 TSI hybrid.

Ok my mistake, the 1.4, but point stands it has plenty of power.  Are they really 2 tonnes? My diesel Passat was 1,520kg I am not sure they are carrying 500kg of batteries for a 30 mile range.  Internet says 1635kg for Passat GTE.

But as above if you floor it it will find some power from the battery.  The issue is if it tries to reclaim range from the engine, which is normal in a non-plugin hybrid. But you don't want it to refill the entire battery using the engine.

FunkyDunc

Dunno – its a 2019 diesel Merc E Class

Probably is then. Reason I mentioned it, is your usage is roughly 5 times lower than the expected amount for a VW for example.

Hmm must have misread the weights table and remembered the max loaded weight, even the Arteon GTE shooting brake is well under 2 tonnes at 1.800 kg. Going off for another look :D.

I recently bought a diesel passat which seems so far to have been a sensible choice.

It's a 2015, it meets Euro 6 so no charges for cities, but it also doesn't have an AdBlue system so nothing to worry about breaking down there. A quick check of the DPF health showed it only has a 52% ash build up so it should outlast the rest of the car given it's taken 113k miles to half fill it. Cleaning the ash out isn't really complicated or expensive these days anyway.

It gets run for both short stop start journeys around town and occasional long runs for work once a week and touch wood hasn't had any emissions related issues yet. You can feel when it is doing a regen as the idle rises to 1,000rpm and sometimes you interrupt it when you stop, no problem it just resumes it next time you turn it on. Doesn't seem to dump any fuel into the oil like some engines do when this happens as the level hasn't risen in 6,000 miles.

With my mixed use it gets an average 52mpg and diesel costs the same per litre as petrol now, so it's costing me a lot less in fuel than the petrol Seat it replaced which never managed to average more than 37mpg.

a decent slowing/braking event event at motorway speeds in our Zoe can add several miles to the guessometer.

it doesn't actually add that much range though. If you imagine coasting to a halt at 70mph - its pretty unlikely you'd get "several" miles - and that would be the case if you had 100% recouperation during regen.

Dunno – its a 2019 diesel Merc E Class

I would guess the dealer is brimming it at service time. the tank is a pretty big 25l - I suspect they've done that to avoid user inconvinience. For comparison, our zafira has a 5l tank (I think) and it needs more every few months - maybe 2l per 1000miles consumption.

A quick check of the DPF health showed it only has a 52% ash build up so it should outlast the rest of the car given it’s taken 113k miles to half fill it.

My Mercedes was on 12% at 82k miles.  52% sounds like a lot.  Possible that someone's used the wrong oil at some point.

Doesn’t seem to dump any fuel into the oil like some engines do when this happens as the level hasn’t risen in 6,000 miles.

It can burn the oil as much as its letting fuel into it, so the level can stay the same.

it doesn’t actually add that much range though. If you imagine coasting to a halt at 70mph – its pretty unlikely you’d get “several” miles – and that would be the case if you had 100% recouperation during regen.

My EV had a little gague showing you how many miles it recovered each time you'd brake.  Coming off a motorway from 70 would add about 3/8 of a mile.  The only place I ever managed to gain a mile was going down Dinmore hill on the A49 which is about 3/4 mile of 1:10

A quick check of the DPF health showed it only has a 52% ash build up so it should outlast the rest of the car given it’s taken 113k miles to half fill it.

How is this check done?

What puts me off another diesel is the oft quoted 'average' lifespan of 100k miles for a DPF.

Our 10 yr old Polo ended up asking for a regen really frequently (yellow dash warning light), so I assumed that the DPF was getting full up with ash.

If there is a way of knowing what the current DPF health is fairly easily and changing a DPF is actually not that expensive a deal these days, then I might reconsider for our next used car.

For my particular use it’s financially better to run two vehicles...I consume a lot less fossil fuel by splitting my driving between a van (33mpg) and small diesel car (60mpg).

The saving in fuel by not using the van 100% of the time more than covers the running costs for the second vehicle (fuel, VED, MOT, consumables, insurance, servicing), with a comfortable surplus towards deprecation and unknowns.

Obviously I have no idea about your financial arrangement, but surely just looking at running costs doesn't consider the cost of buying the second car (or failing to sell the second car)...?

A 1.5 dtci grand Cmax has spcome up near us.
We have never had a diesel before , will a 4 mile stop start commute each way be bad for it?
Every other weekend it will have a 130 miles round trip on the motorway.

zippykona

A 1.5 dtci grand Cmax has spcome up near us.
We have never had a diesel before , will a 4 mile stop start commute each way be bad for it?
Every other weekend it will have a 130 miles round trip on the motorway.

It should be fine.
I think I said it earlier in the thread, but probably easier to repeat than find it.....my Wife commuted for ~4 years or so to her previous job in a 2 litre diesel Ibiza and that was <2 miles away. It presented no issues.
A regular 130 mile round trip should blow the cobwebs away.

The only thing I would say to caveat this, is that several years ago the local garage I use mentioned that we would be better off running branded fuel in our cars, rather than supermarket fuel. He said that whenever he sees dpf & EGR valve issues with diesel cars, most times when asked the driver says they predominantly use supermarket fuels.
So, that's what I try to do - run branded fuel where possible. This comes up on here every now & again and can be a topic of great debate/argument over whether there is any difference. For me, it seems like a sensible precaution to take & having taken my car to this mechanic for ~20 years now, I trust his advice.

Our 10 yr old Polo ended up asking for a regen really frequently (yellow dash warning light), so I assumed that the DPF was getting full up with ash.

Not necessarily, it could be another fault that has caused the engine to smoke and is filling up the DPF. The car knows the ash load and the current soot load as different values and they are both accessible using OBD2 readers Is expect.

Obviously I have no idea about your financial arrangement, but surely just looking at running costs doesn’t consider the cost of buying the second car

We borrowed the money, and the reduced fuel cost can be offset against the loan repayments and insurance.

Re branded v supermarket fuel. Surely as there are only a few refineries in the UK, all the diesel is coming from them and therefore the same to all end retailers, ie standard or posh with some additives.

Maybe mostly supermarket fuel users are mostly running about locally hence filling up when shopping and the high mileage bunch are filling up anywhere so use more branded fuel..... dunno? That might fit the pattern of dpf/egr issues.

Obviously I have no idea about your financial arrangement, but surely just looking at running costs doesn’t consider the cost of buying the second car (or failing to sell the second car)…?

Correct that it doesn't consider the second vehicle cost, but I'm (very) lucky that I own both vehicles outright: it wouldn't make financial sense if I had lease or loan payments on top. One downside is tying up funds in the second vehicle though. I appreciate it's a rather narrow set of circumstances that make this a plausible situation.

zippykona

A 1.5 dtci grand Cmax has spcome up near us.
We have never had a diesel before , will a 4 mile stop start commute each way be bad for it?
Every other weekend it will have a 130 miles round trip on the motorway.

Another +1 to 'it'll be fine' for pretty much what @stumpy01 says. Issue with any used vehicle is not knowing what previous use it's had - you won't know (for sure) if previous owner has done exclusively town use with zero long journeys. Same can be said for any used purchase though.

The only thing I would say to caveat this, is that several years ago the local garage I use mentioned that we would be better off running branded fuel in our cars, rather than supermarket fuel.

We found that both the Galaxy and V70 'preferred' branded fuel from MPG point of view, and I don't know about the rest of the engine. I also a few times year filled up with the premium fuel before a long trip to help it 'clean out'.

Current 1.4tsi does get better mpg on Shell - and currently our local Shell garage is same price as Tesco.

He said that whenever he sees dpf & EGR valve issues with diesel cars, most times when asked the driver says they predominantly use supermarket fuels.

It could be a statistical anomaly though because most people use supermarket fuels most of the time, so it is highly likely that whoever comes in with a DPF or EGR issue they will have done that. You would need to gather two samples of people, those who use branded and those who use supermarket fuels, and assess incidence of problems in each group.

molgrips

It could be a statistical anomaly though because most people use supermarket fuels most of the time, so it is highly likely that whoever comes in with a DPF or EGR issue they will have done that. You would need to gather two samples of people, those who use branded and those who use supermarket fuels, and assess incidence of problems in each group.

Yeah, exactly. It could be.....or it could not be. I have no way of verifying this myself.
So for the few pence/litre extra it might cost I am happy to use branded fuel wherever possible.
I just wanted to make the point that it might be a factor why we have so far seen no engine issues despite a daily short commute with a diesel engine, in relation to zippykona's question about usage case for the car he's potentially buying.

We had a new Toyota Corrola Estate PHEV as a hire car in Sicily last year.  It averaged 69.9mpg over 1200 miles with 4 people in it and the Aircon running all the time.

I would be buying a small car with a big diesel engine. We have a BMW 1 series with the 2l turbo diesel engine. Its plenty quick enough, averages between 50 and 60mpg, it does 48mpg with the full bike carrier hanging off the tow bar. At the same time its eco. We bought it second hand, so no manufacturing pollution,  and only attracts £20 year in VED its deemed to be so green.

My Mercedes was on 12% at 82k miles. 52% sounds like a lot. Possible that someone’s used the wrong oil at some point.

doesn't the ash get burned off periodically anyway, so the amount you show on your reading is like looking at the amount of fuel in your tank at 80,000 miles and basing the fuel economy on that?

doesn’t the ash get burned off periodically

As understand it, the soot is what is burned off during a regen. The ash is left over from traces of engine oil that have been burned in the engine, which is why if you have a DPF you need low-ash oil. It cannot be removed because it's the non-combustible residue - that's why they call it ash.

I notice that a 17 Cmax has £35 tax and an 18 £180.
Are there plans to make pre 18 diesels the same price as 18s?

Are there plans to make pre 18 diesels the same price as 18s?

No. The model changed because more cars were less polluting. Our car is £20, later of the same were the same flat payment you're seeing.

If anything they may change earlier cars back to a flat model

I have a 2l Turbo petrol car and a 1.6 turbo diesel van. The shortest journey I'll ever do (which is rare as I normally cycle) is a 20 mile round trip. I'll normally do 70 miles each way to work, spread over several days, both minor A and B roads, and a 70 mile round trip to the beach on minor roads.

Petrol 33mpg. Diesel 36mpg.

My adblue system failed. Basically between the manufacturer and various technicians we never solved the problem, but drained my wallet of 2k. In the end, the system was disabled for £200 by a mobile technician.

I would always get a petrol, if that's an option on your choice of  vehicle. I would avoid hybrid looking at your mileage, you'll suffer mpg-wise.

If buying a diesel, I'd delete the adblue the day the warranty ran out.

If buying a diesel, I’d delete the adblue the day the warranty ran out.

But do you not care at least trying to do your best for the environment ?

Did you not read all his post?

If buying a diesel, I’d delete the adblue the day the warranty ran out.

Don't.  It makes your car run better, see above.  Sure, it failed on your car but anything can fail.  That's modern cars for you, and emissions control equipment is the price of a better world.

<p style="text-align: left;">We bought it second hand, so no manufacturing pollution</p>

Slightly generous here.  The car was still manufactured, and someone presumably sold that car to buy a new one - which was also manufactured.

Yeah, if you didn't buy used cars then their value would be lower which means someone woudl be more reluctant to buy a new one - possibly.

A rep came in moaning that she will have to pay ulez even though her diesel car is only £35 tax.
How does that work?

A rep came in moaning that she will have to pay ulez even though her diesel car is only £35 tax.
How does that work?

Zero tax & zero ULEZ for my dirty diesel 🤔

Upto end march 2017 ved was based on CO2 emissions, so low CO2 = low VED, but earlier than about Sept 2015 & it won't meet ULEZ limits on NOX at a guess?

Adblue systems aren't inherently bad - there are lots of trucks with them still working perfectly with many many hundreds of thousands of miles on them. And all manufacturers have put a lot of work into making them generally reliable - SCR is a much better idea than the cludge of EGR to reduce NOx.

On a different note, my son has been looking for a first vehicle, and there seem to be a lot of good, well priced Euro 4 and 5 diesels available in the SE (making a buying trip worthwhile). Small dealers are keeping and selling-on good but old part-ex cars that have only been changed due to ULEZ (so haven't had WBAC and auction slices added to the window price like a lot of 2nd hand sales stock). It would be environmentally bad to prematurely scrap otherwise functional vehicles so guess it is acceptable to use them up in areas less troubled by local air quality.

But do you not care at least trying to do your best for the environment ?

Erm, what on earth?? I spent 2k trying to do just that! Renault HQ France couldn't figure it out. My van was coming up to an MoT and it was basically a write-off, unless I deleted it.
It's such a common failure, there's a whole industry in deleting them. It's a fudge to pass NOx levels in towns. As I do near zero urban driving my deleted system has limited impact on the environment.

Don’t.  It makes your car run better, see above.  

Not necessarily so...my van is returning better mpg and running sweetly now the adblue has been deleted..... I'll either get a petrol van next (Nissan Townstar LWB) or another Trafic and delete the adblue at 3 years old + 1 day. I can't afford not to... the cost of these systems is prohibitive...No guilt felt on my part whatsoever!

An interesting read.

We dropped the 2nd car for an electric moped as we're out in the sticks so an ebike wasn't practical enough (tennis/golf 20 mile round trip, weekly trip into work 30 miles). It's worked well so far in case that's less of a jump for the OP.

Our only car, a 2016 Outlander PHEV, works well as the single car as it's essentially an EV during the week and then generally full to the gunnels with bikes/dump runs/IKEA/camping stuff at the w/e.

Yes, I'd like the mpg to be above 40 on petrol alone but 35 is more likely. And yes, the once high score of 30 mile range is now more like 20. But with a 4yr old scrambling all over it we're going to sweat this asset until he's driving! 🙂

It’s a fudge to pass NOx levels in towns. As I do near zero urban driving my deleted system has limited impact on the environment.

Just to correct this - SCR is most effective outside urban driving as it needs exhaust temperature to work - so you are definitely emitting WAY more NOx without an SCR.

SCR systems are categorically not inherently unreliable - I engineer these things as a day job and have never seen a whole system fail to the point it was impossible to know the cause. They are relatively simple systems. The main things that can go wrong are deposit buildup - can be cleaned off or just disappear during a DPF regen - or NOx sensor failure (most common failure I’d say).

Removing an SCR also won’t increase performance in any way - there is nothing they do that reduces performance in the first place and -as mentioned- allow much less EGR to be used = better mpg = lower CO2 = less soot = less DPF regens = less chance of DPF blocking.

They aren’t perfect, but they are very very good - near 100% conversion efficiency in extra-urban and highway conditions.

That Honda mentioned above uses an LNT - this stores Nox and then purges it by running rich for a while. I cannot make this as an absolute statement, but it’s likely over a witch the LNT won’t need to purge frequently with the result of great NOx and low CO2. On the road at high nox conditions, that might be a very different story. LNTs have basically been ditched by the industry even though they are a lot cheaper than SCRs because they are nowhere near as effective in real world conditions.

The amount of AdBlue used depends entirely on how you drive the car. Trundling down the motorway at 70mph will use almost none. Doing 90+ will drain the tank within 5000 miles.

My old Volvo V90 used to get about 15,000 miles to a tank of wee with mostly motorway driving at lower speeds.

I engineer these things as a day job and have never seen a whole system fail to the point it was impossible to know the cause.

I've seen a (small) handful. Less than 10. But then, i used to deal with warranty on emissions systems...

At the point i stopped dealing with them, we had around a million adblue/Eolys/SCR equipped cars in service. Faults were generally easy to diagnose and fix.

Generally those that were impossible to fix (other than rip out and replace) had been run with a fault for 10s of thousands of miles.

It’s a fudge to pass NOx levels in towns

It's not a fudge.  It's the best way to solve the problem.  By deleting it you are not solving the problem.  I appreciate it's an issue, but we are where we are.

the cost of these systems is prohibitive

As above, it's not an inherent cost in the system.  You were just unlucky. I also spent £2k trying to get my engine ECU working properly after a shit mechanic screwed it up, but that doesn't mean engine ECUs are 'prohibitively expensive'. They are just part of a modern car, and a part from which we all benefit.

In the old days motoring was about regularly replacing lots of stuff due to wear, then there was a period of really long lasting cars, but now we have cars that are generally much more reliable but you have a low chance of a really expensive bill.  C'est la vie. Go electric next time.  I firmly believe that the chance of a battery issue is going to be far less than something going wrong with all the intricate engineering under an ICE bonnet.