[Closed] DPF regen causes diesel to be not as cheap as you think shocker...

Not a regen issue as such , but when mine does do a regen i lose about 5-7 mpg for that tank ! .. the mpg just plummets ! .. lowest ive seen is 49.7 mpg .. which compared to yours is good

I've done 18000 miles in my mk3 focus from New and never noticed a regen happen. I must have a dpf on a 2014 car surely.

Jesus! My 1.8t petrol Octavia vrs can achieve that. What car is it?

Thats 39.9 during a 25 miles round trip with 20 miles on the M25 stop start and the regen happening for most of that.

I have read in some cards its not as obvious as others. In our Ford Kuga, and can feel it going a bit flat. I the Alfa (this one) it goes flat for 10 minutes. In fact 2 days ago I had a seized rear caliper fixed, and I has a minor panic think it'd seized back on, pulled over and felt the rear disc & caliper, which were warm and the same both sides, it was then I noticed the lumpy tickover - another sign of regen.

I would add that the same journey came out at 46mpg with no regen last night.

A regen is the last resort for burning off particulates - normally if your journeys are too short / low engine load so the exhaust does not get hot enough to burn them off unaided.

[i]DPF regen[/i]

A what now?

Every day's a school day. Now I know what's causing my intermittent hot and smelly rear end (arf). Initially thought it might have been brakes (on exhaust side) binding, but inspection resulted in no burnt fingers. Thanks!

[url= http://www.pistonheads.com/gassing/topic.asp?h=0&f=23&t=1419435&mid=0&i=20&nmt=DPF+regen+cycles%2Dhow+often%2C+how+to+know+%26+what+to+expect%3F&mid=0 ]Interesting PH thread on this[/url]

A regen is the last resort for burning off particulates - normally if your journeys are too short / low engine load so the exhaust does not get hot enough to burn them off unaided.

Using Google, you'll find a lot of cars initiate the cycle every 300 miles or some such interval. I've done 1100 miles in 3 weeks, mostly m/way and all with BP Fuel (1.5 tanks Ultimate, the current normal).

Diesel it Satan's fuel!!! Trust me I'm an engineer*...

*automotive engineer - so for once it is a semi relevant thing to claim!

Diesel's day is over, wouldn't buy another personally.

[url= http://www.telegraph.co.uk/motoring/news/11007326/Diesel-car-drivers-betrayed-as-EU-cracks-down-on-Britain-over-air-pollution.html ]Nitrogen Dioxide init[/url]

My Leon would suffer really poor MPG when regening.... but then it's method of raising the engine/exhaust temp is to chuck loads more fuel in!

Yeah, mine comes on at annoying times and takes 15mins of less power, delayed throttle response, burning smells and a wheezing engine sound.

It would be great if cars could let you know when one is coming up and you decide when to instigate it (up to a point), by pushing a button. That way you could time it for a longer run instead of during a short trip that may be less time than the regen time.

I've not noticed mine entering the regen cycle but if you add in the Webasto auxiliary heater kicking in during this cold snap the between fill average is now in the very low 30's.

I know I should have gone for more cylinders and a supercharger.

One of the certainties of Alfa ownership is a disappointment that it doesn't work as well as it looks.

Diesel's day is over, wouldn't buy another personally.

Nitrogen Dioxide init

* 😐 while waiting for first ever diesel car to be delivered *

I know I should have gone for more cylinders and a supercharger.

Yes, if buying new I'd buy one of the new 60mpg petrol engines. I needed a cheaper 5-6yo car as a stop gap though.

I've been out to several breakdowns where the reported fault is "burning smell and stop-start not working". So I explain that it is't a fault, simply the ecu trying to do a dpf regen.
People I have been out to complain it always tries to do the regen at stupid times, a particular favorite seems to be as you pull onto the drive so it sits there gently smoking and stinking the house out.

I know I should have gone for more cylinders and a supercharger.

Yes, if buying new I'd buy one of the new 60mpg petrol engines. I needed a cheaper 5-6yo car as a stop gap though.

Nope, not new as they stopped making them over 7 years ago and definitely nowhere near 60mpg. Talking about an S-Type R (V8 400+ horses), whereas I bought a V6 2.7D on a whim without thinking too much about it. Lovely car, roof racks for the bike but low 30's from a diesel after a MK3 Mondeo TDDI and close to 50 bit of a shock.

My wife's Fiat 500 multijet does a regen around every few hundred miles or so depending on how its driven. The dpf light has only ever come on once a 70mph blast in 4th up the motorway cured that. Average mpg is around 52-55. We were told in no uncertain terms by the fiat dealer [u]not[/u] to buy a diesel with a dpf for pootling around town. She does a lot of motorway driving, its never been a problem. We tested a 1.2 petrol 500, my farts are more powerful.

So really the title should be - diesel car not suitable for stop start journey on m25 shocker.

[i]* while waiting for first ever diesel car to be delivered * [/i]

*While having just purchased my second diesel but seriously not giving a shit what people on STW say*

New car needs an Italian tune? 🙂

DPF regen

A what now?

Its like in Doctor Who

Kryton now looks like Peter Capaldi. If it happen again he'll look like Idris Elba

[Spoiler alert]

[i]I know I should have gone for more cylinders and a supercharger. [/i]

No, more cylinders and swap supercharger/turbo for cc 🙂

[URL= http://i992.photobucket.com/albums/af45/bruce_nikki/P7020013_zpsab160111.jp g" target="_blank">http://i992.photobucket.com/albums/af45/bruce_nikki/P7020013_zpsab160111.jp g"/> [/IMG][/URL]

Sorry, but the reason your car is "only" doing 39.9mpg is because you can't drive for s**t.

(A single DPF regen uses approximately a maximum 150cc of fuel to light off the trap. Your car has a fuel tank that holds probably 60 litres.)

Sorry, but the reason your car is "only" doing 39.9mpg is because you can't drive for s**t.

Educate me, oh wise one.

Kryton57 - Member

Thats 39.9 during a 25 miles round trip with 20 miles on the M25 stop start and the regen happening for most of that.

Depending on what you mean by 'stop start' I would say that 40mpg during driving that consists mainly of accelerating, braking or sitting still not moving isn't too bad.....

Perhaps you are expecting too much from a diesel?
If you aren't moving, you aren't doing your fuel economy any good and if you are constantly accelerating and then having to brake you aren't going to get massive mpg numbers.

Coming to work today my mpg was up to about 56 before I hit the back end of the normal traffic on the A14, about 25 miles into my commute. By the time I got moving again up to 'normal' speeds, it was down to 50mpg. And because you are sat still for so long with your mpg dropping, it takes longer for the average to come back up.

This is a shocker? I thought the was common knowledge! I'll be going back to petrol soon as I'm no longer doing the miles to warrant owning a DPF equiped car, that and modern day patrols get good enough mpg for my liking.

Indeed stumpy, its not me that's arguing my MPG is crap and my driving skills are at fault.

A regen won't help it either. Maxtorque needs to read the thread - for the 3 weeks I've had the car either some or all of that time has also been spent with the rear caliper binding. Hence in the 45 minute journey after it was fixed, from Dunstable to North London sandwiching the M1 and M25 between the rush hour traffic at each end the car averaged 51.8mpg.

But my LIFESPAN OF THE CAR MPG is showing 39.9 I suspect influenced by those reasons, and who knows, maybe the previous owner drove around town all day for the 3 years he had it.

I'm also getting new boots in Monday as mine really are the shitiest tyres in the world. After that I'll reset the Total trip/average/range and see what I on the fixed setup.

My journey during the week is 8 miles each way, I travel fairly good distances for leisure purposes at weekends.

My DPF is not even noticeable, no issues and consistent performance.

Love diesels.

so 39.9mpg is average for the trip or cumulative average? If it's cumulative average and you don't know when that was last reset, then why not just reset that and see how you get on?

My Wife's Ibiza (with dpf) is a 2 litre with 140bhp & until recently she was averaging around 50mpg on her 'through town', fairly stop-start commute.
Now she's doing a longer, more free flowing commute she is regularly seeing 60mpg average on the computer, so even accounting for several % of optimism on the computer's behalf she is still getting 55mpg or so.

I drive her car every now and again, and can't say I've notice it doing a re-gen. How do you tell?

Her previous 1.6 petrol 308 struggled to get 40mpg.

I've had 2 cars now that allegedly contain dpfs (f20 and f25). The car does lots of school runs and the odd motorway run.

I have never once noticed this dpf regen thing you mention.

I'm now close or maybe just below the break even point for petrol v diesel but prefer the way this engine feels to its equivalent petrol.

How do you tell

Common signs on older Alfa's

a) Performance is slightly flat
b) If you are looking at current fuel consumption, it'll be very low in comparison to the normal
c) Slightly jittery rev needle at idle
d) Car smells hot/burning smell if its still and you are outside the car
e) The Alfa turbo needle drops "suddenly" off revs, rather than the usual gradual retreat.

Thats from the Alfa forum and ties up with my experience with the exception of the turbo needle that I wasn't watching.

I have never once noticed this dpf regen thing you mention.

It might not kick in as it hasn't met the parameters - continious running of the engine at constant speed etc. It'll keep going and filling up with soot for thousands of miles perhaps until the DPF gets to a point where the ECU will force a regen - you'll get a light on the dash, and the garage should tell you to go an drive along a motorway or similar for an hour at mid revs / 60/70mph.

I had to go through the whole diesel/petrol thing this time last year.

I only do 15k a year but it's all long journeys (cycle to work, supermarket is 1/4 mile away and quicker to walk, Big shops done on the way back from somewhere if needed) so the short journeys issue didn't factor into it. Even taking into account the equivalent diesel engine would get 10mpg more than the petrol one I bought the added cost of purchase, servicing and the usual life of the DPF, DMF and depreciation meant the petrol came out cheaper by a decent margin. The fact that I'm actually getting better mpg out of my car than the book suggests (50mpg vs 47.6) means I will always be better off with the petrol.

Depreciation is the biggest cost on any car, fuel is just more noticeable as it comes out of your pocket every time you fill up.

Wait - you mean automatic regens, rather than taking it to the garage?

You've got 40mpg and you're doing lots of stop start journeys? That's not too bad on a brand new car if you ask me.

Anyway - re DPF regen - there are two kinds, in VAG land at least (and probably others, BMW I think). There's passive regen, where it advances timing and reduces EGR to get the exhaust temperature up. You should not notice this in terms of performance, but it might sound different. This uses no extra fuel, and will work fine in normal driving. If you aren't driving it enough for this to work, it then initiaties active regen, which is where it's squirting extra fuel into the exhaust stroke which oxidises on the DPF cat and increases temps to burn the soot. This would harm your MPG.

I think it tells you it's doing this, because it doesn't want you to stop the car when this is happening. If you do, it'll then put a light on and according to the manual you need to take corrective action - take it for a dpf cleaning drive.

EDIT oh.. is your car not brand new? In that case.. on the previous thread.. some people are only getting 40mpg from their diesels.. and some are getting 60. There's a knack to it, don't expect the car to do all the work...

Depreciation is the biggest cost on any car

Not of anything I've ever bought 😆

Maybe I've been lucky but since going diesel (170 common rail vag units in both cars) we currently do twice as many miles to the same amount of fuel as our previous petrol cars did whilst the performance in most circumstances is better.

Some very bold claims from the very latest petrol cars but they feel so slow at low revs you have to push them to get anywhere and then the mpg drops off the table.

My neighbour recently had one of those 1 litre 3 cyclinder turbo fiestas which have won many awards. Driven at all spiritedly it would drop below 30mpg on a combined route. The forums are full of many unhappy owners who purchased for the potential fuel savings.

http://uk-mkivs.net/topic/31023-dpf-regeneration-information-must-read-for-all-drivers-of-dpf-equipped-cars/

Noddy question (and I don't own a diesel) Can an owner do [i]manual[/i] a DPF clear out? i.e. empty out the accumulated particulates by hand/bag them out and take them to waste disposal for themselves? or is it a garage only job?

My octavia has done it twice in 5000miles. Both times after I'd parked up. Not noticed it whilst driving but it's rare for me to be queuing too long. Not sure of the stop start ignition thing makes a difference either.

I've been driving diesel A4s and Passats for 14 years now, probably 220,000 miles in total and never heard or seen this event. It might be because for 15 of my 21 mile commute I'm driving like I stole the car.

I have had a good look around underneath my Passat and been surprised at the amount of effort the designers seem to have taken to keep the entire exhaust system well away from the floorpan and anything combustible.

C220 Coupe Mercedes here. 180bhp diesel

55mpg average up until the recent cold weather in which case it has dropped to a depressing 53mpg.

Had highs of 70mpg over a 60mls journey and never gone below 40mpg even driven like an idiot.

Fitted with DPF filter but tbh in the last 2 mercs I have had (C200 Saloon previously) I have never noticed a regen. I et the speed control (Fancy speed limiter) at 80mph and other than that drive it normally (I am not a slow driver).

Can an owner do manual a DPF clear out?

You mean when it's out of the car? I guess you could blow some sort of hot gas through it... maybe a blowtorch would do it. Worth a try if it's knackered already.

I've been driving diesel A4s and Passats for 14 years now, probably 220,000 miles in total

They weren't on every car until somewhere between 2006 and 2008 I think.

Just be carefull with anything relating to regens and anything outwith main dealers.

The nature of most of the regen systems is to inject fuel in to burn of the deposits. Any excess fuel is distributed back into the vehicles oil. This is actually accounted for in the vehicles ecu and a certain level of fuel/oil mix is acceptable. Its when vehicles annoy owners by coming up with repeated regens which maybe don't get completed and then eventually get told to get the vehicle in to the dealership that things go a bit wrong. Owners have a nasty habit of saving a few quid and taking the vehicle in to back street garage for them to 'rest' the regen counter. Unfortunately this doesn't then take into account all that fuel floating about in the oil system which will now be unaccounted for......

Or so I am told

would a 2007 Saab 9-3 1.9TDCi have a DPF?

I used to notice occasionally on the motorway at 70 (when possible!) that the engine would feel lumpy & unresponsive, then after about a mile it would sort itself out. DPF regen? no matter, not my problem now, the Saab got sold in 2011ish

Kryton57, you said you'd notice it in your Kuga, what are the symptoms? just much lower than expected indicated MPG for a while?

BTW 40mpg in an Alfa I'd say is quite respectable! even if it is a diesel 🙂 I had a 146 1.6 with the boxer petrol engine, never got better than 32mpg, then a 156 1.6 T-Spark, which never gave more than 35mpg

Kryton57, you said you'd notice it in your Kuga, what are the symptoms? just much lower than expected indicated MPG for a while?

Its hardly noticable, in fact if I'm talking with my wife or chatting with the kids I'd miss it. The two occasions (ours is used mainly for the school run) I've experienced it I've just felt that the throttle response was ever so slightly muted.

Its much more noticable in the Alfa but then the torque isn't so strong at 1500 Revs in 6th as the Kuga's is.

The DPF in our Golf just failed, it warped! Apparently there was nothing we could have done to prevent the failure. We're still under warranty but the DPF is not covered. Close to a £1200 bill (that's with a dealer contribution as they're feeling guilty)... Not best pleased! Currently arguing the toss with VW.

Is there any way of telling if a car has a DPF or not? I bought a 2007 Passat 2.0 Tdi recently, the DPF was still just an option at that time (I think!). Any way of finding out for sure?

We were all set to go diesel with our latest sensible car. Then went petrol in the end. Fewer nasty emissions, £1500 cheaper than the equiv diesel (which buys a lot of fuel), fewer expensive things to go wrong, does 60 mpg if you drive like a Vicar, 30 mpg if you rag the living shite out of it. I once managed to get it down to 28 mpg by redlining it up and down the box in the lanes, just to see. Modern petrol cars are amazing, if boring.[/smug]

Had mine removed before Christmas .... Glad to see the back of it ...nothing but trouble

My Fiesta regens every couple of weeks or so.

I'm doing 400 - 500 mile a week mainly town stuff with the learners. It bounces all over the shop and the idle is awful when it regens.

Also kicks out loads of grey smoke. Depending on who I'm teaching, I wind them up and tell them they have broke the car 😉

I usually prevent it regening by taking the roofbox off and caning it between lessons, all within legal limits but you get some filthy looks when a learner car accelerates hard away from the lights so it's better to take the roofbox sign off.

Another way is a blast down the motorway every 10 - 14 days. I know its natural for it to regen, but I worry if it did it on test and the examiner thought it was broke.

what's a regen smell like ?

every now & then my car smells of burning rubber, to the point where I go & check the tryes for rubbing. I'd never thought it could be the DPF

?? ❓

*googles, sees it does, relaxes, deletes noob question*

😀

Can't you just get rid of the dpf and get a custom engine remap whilst your at it..

Can't you just get rid of the dpf and get a custom engine remap whilst your at it..

I did

I beleive not having a DPF (on a car that should) is now an MOT failure.

How vigilant the testing centres are on this I don't know

I don't think all dpf dump spare fuel into the sump but apparently my Mazda 6 does. Hence mine was serviced then 3k miles later needed another oil change due to a failed regen. Never mind the cost of mpg, factor in the cost of, essentially, another service and diesel cars seem quite expensive.
It's great to drive and no car is cheap but there are significant hidden costs IMO.

I beleive not having a DPF (on a car that should) is now an MOT failure.

Take the filter off, remove the internal gubbins, weld it back up and put it all back in place.
None the wiser

I beleive not having a DPF (on a car that should) is now an MOT failure.
Take the filter off, remove the internal gubbins, weld it back up and put it all back in place.
None the wiser

Yup, aware of that solution. i interpreted your statement that you'd literally taken rhe DPF off the car, rather than the more sophisticated approach. My mistake 😀

Due to a clogged DPF I am today £1500 worse off.

With a new DPF fitted it's an ideal time to get rid of the diesel car and go back to petrol.

Diesel cars PITA!

D*F two 3 letter acronyms that are making 3l v6 petrol cars seem appealing from a running costs perspective.

Edit on reflection I maybe looking for excuses I miss my 406...

I lurk on two motoring forums. One Honda and one Mercedes.
Only very very occasionally is DPF mentioned on the Merc forum but it has its own folder on the Honda forum. I have had no problems owning a Merc diesel (I've never smelled a regen from mine or I think had one in 26k) but I wouldn't buy a Honda diesel. I use our Honda petrol all the time around town. Not even a blown bulb from the Accord in 5yrs.

This thread is why last week I sold my Mondeo diesel and bought a Kia Soul petrol.

Over the last 5 years, I've put around 170,000 miles on three different diesel engines - no DMF issues, no EGR issues and no DPF issues.

Meh

weeksy - Member
This thread is why last week I sold my Mondeo diesel and bought a Kia Soul petrol.

POSTED 23 MINUTES AGO # REPORT-POST

Time travel!!!!!

You win t3h interwebs 😀

What numbers for tomorrow's draw please? 🙂

Kryton, you need to go and rag the living daylights out of it. Sounds like the previous owner was a 6th gear @ 20mph specialist and it's a bit bunged up. Might need an oil change for good measure.

It's an alfa, drive it like it should be driven and it'll reward you.

It's an alfa, drive it like it should be driven and it'll reward you.

Hooked up to the back of an AA truck?

With my Yeti I ignore the change up Arrow as it's wrong most of the time. I will only cruise in 6th at about 1750 rpm and above. The DPF light hasn't come on once in 3000 miles so far. Much happier in 4th and 5th in and around town. MPG is about the same 42ish, I was getting 30ish out of the VRS pootling about. You still have to drive these cars and not pootle about at low revs looking for every MPG.

Yep my yeti's the same. Wants you to bimble along grinding the arse out of the big ends at 1000rpm. Just sounds and feels so wrong. Dads dsg-equipped Superb is also the same. He's taken to switching it into manual mode and holding the gears a little longer than auto would. No difference in mpg but undoubtably less miserable for the rods and crank.

Chipsngravy what car was that?

Kryton, you need to go and rag the living daylights out of it. Sounds like the previous owner was a 6th gear @ 20mph specialist and it's a bit bunged up. Might need an oil change for good measure.

It's an alfa, drive it like it should be driven and it'll reward you.

Once I have removed the suicide tyres on Monday, I'll give it a few more beans.

This thread is why last week I sold my Mondeo diesel and bought a Kia Soul petrol.

I think the problem here is that the manufacturers fuel consumption figures are ludicrously optimistic. I know there are regulations for how they are reached but they don't reflect in any way how are a car is likely to be driven in real life.
If you're a business user and someone else (customer I suppose) is paying/time is money etc then you won't have DPF issues. If you're a private user and buy a car that has good fuel consumption numbers then there's a good chance you'll try and achieve them. If that car's a newer Diesel with a DPF you'll clog it up.

On a related note, I own a Diesel estate but I really don't do enough miles and, as I'm looking to replace it, I'm considering petrol. If I go on Autotrader and search: £20k to £35k, within 100miles, <20,000miles, automatic & estate I get 597 Diesels, 28 hybrids, 30 petrols & 2 unlisted. Twenty times as many Diesels as petrols 🙁

If I wanted a petrol XC60, it would be a 3ltr turbo and Volvo sold about 10 in the UK. Would cost me over £400 to ved it, rather than £200. And for urban would do about 15mpg. So , for Volvos best selling current vehicle, means that diesel is the only option. We have had diesel cars for the last 8 years for the family car and they chug 4 miles each way to work for the missus, twice a day, as she comes home for lunch and we have yet to face a dpf issue. All of them had DPF's fitted. Later cars have a different form of regen that earlier cars and the materials of the dpf are better than earlier versions. Wifes going to go for a blast for 20 miles shortly, to go shopping, so that's the regen sorted. And its not made us go out of our way to do the regen.

Thrustyjust - Member

This thread is why last week I sold my Mondeo diesel and bought a Kia Soul petrol.

Christ mate, has life got you down that much ??

Not at all, the Kia has 3.5 years warranty, it gets 42mpg average, ok, it's not as nice, nor plush as the Mondeo, but it's fine.

the Mondeo cost me £700 for a cracked coolant hose, the DPF would need replacing in the next 10,000 miles, it needed 2 new tyres and the clutch would last maybe 20,000. All in all, it was a money pit waiting to happen.

I have a GSXR750K7 for speed, I have mountain bikes for fun.. a car is just to take me to work and back each day. The Kia is competent.

I'm DPF wary but since I fancy a T4/5 with minimum 6 seats the petrol options are limited. Open to suggestions tho!
We had a 2005 Scenic 1.9d which did cause us some dpf regen dealer costs until we figures out how to spot it before it became a dealer issue. Wouldn't buy one again for town driving hence we now have a petrol Jazz.

Weeksy, not sure how many miles your Mondeo had, but my mates on 140k so far and has needed a new clutch at 110k. That's it. No signs of dpf issues yet on a 57 plate car. We put a new battery in it last summer, just because. Other than that , it runs like a dream. He pays £60 a tyre at Newbury Tyres near the Police Station and they are 18's as his is a Titty X. I don't think there is an expected life on some things or taxis wouldn't be doing intergalactic mileage in them and I am sure they don't cut out the dpfs. They wouldn't have the intelligence.

This seems as good a place to ask as any; some Diesels look after their DPFs by injecting stuff. Off the top of my head I'm thinking Mercs and some Frenchies. Anyone have any experience of the reliability of DPFs in those??