Quick one - will be off to Europe on holiday via the ferry soon. If I fill the car up with Super Unleaded rather than normal petrol will I see better range? And if so, is it likely to offset the extra cost?
Possibly, and possibly. It completely depends on the car, driving style and ECU etc. turbocharged cars tend to respond a bit better (general trend, not a rule!)
It also depends on the fuel, as not all Supers are created equal.
Probably depends on whether your car is meant to run on 98/99 octane fuel or standard 95. Probably no benefit if the latter. Is it a high performance vehicle?
driving style
Like an old man.
Unlike my wife who seems determined to meet the nice gendarmerie 🤦♂️
Is it a high performance vehicle?
Ok, not sure. You might have to experiment. One leg on super, one on regular. But then you would need the same driver and the same sort of roads for both. No point you hypermiling down the autoroutes then your wife giving it the beans on N and D roads.
E10 (the cheaper stuff) is more environmentally friendly
E5 might give an estimated 1% or 2% increase in economy, but that probably doesn't outweigh the cost. If your car is suitable for E10 (FSI has been for 20 years, but check inside the fuel flap) then I'd use it
I used to get about 10% better fuel efficiency on a run using Super, which did off set the cost in my 22 year old petrol. Since switched to a dirty diesel van (Euro6)
If your car is suitable for E10 (FSI has been for 20 years, but check inside the fuel flap) then I'd use it
Normally run on 95/E10. Unless it’s changed since last summer, the French are still on 95/E5?
IME (cars and motorbikes) Yes, significantly increased mpg on the better fuel.
If your car is suitable for E10 (FSI has been for 20 years, but check inside the fuel flap) then I'd use it
Normally run on 95/E10. Unless it’s changed since last summer, the French are still on 95/E5?
I honestly have no idea. 95/E10 was widely available but the one to avoid is E85, unless you are absolutely sure that the car will take it without damage
On the economy front, Shell says,
Removes and protects from the build up of performance robbing deposits on key fuel system components such as intake valves and/or fuel injectors. Improved fuel economy using Shell V-Power fuels has been demonstrated in industry standard and Shell proprietary tests. Actual effects and benefits may vary according to vehicle type, vehicle age, vehicle condition and driving style. No guarantees provided.
My carb fed highly strung motorbike loves super unleaded (Aral 102 ftw) as does the giulia, or anything I’ve owned which was either forced induction or meddled with significantly. Otherwise, unless you’re ragging the nuts off it on the autobahn, I’d really suspect you’ll see bot all difference.
My dad went through a phase of shoving their 1.4 tsi yeti full of super unleaded. I’ve finally persuaded him that as he drives like the 85 year old that he is, the benefits are null, especially as it was Sainsbury’s own brand sourced from God knows where.
A4 35 TFSI, so not really. Think it’s intended to run on 95 but I thought modern cars automatically adapted?Only up to a certain point. Generally will protect as best as possible for lower fuel grades. And "ignore" grades higher than required in the manual. Though you might get slightly better consumption etc. due to different additives.
Last year I drove a 2004 Astra to the Alps, then to the coast, fully loaded with roof box. So working hard up the hills with less than 100bhp.
Economy seemed better on a tank of Super unleaded, by about 40 miles on a 50 litre tank.
As I understand it, higher octane fuel is less prone to knock or pre ignition.
Cars with fuel injection have knock sensor(s) on the block (along with the other sensors), so can adjust timing on the go.
The old (1986) Bosch Motronic ECU in my 944 had one knock sensor and also a fuel quality switch, you could adjust with a screwdriver which would make it run richer and retard the timing, from the default high octane setting. I assume only needed in areas with poor quality fuel back then.
On the economy front, Shell says,
Removes and protects from the build up of performance robbing deposits on key fuel system components such as intake valves and/or fuel injectors. Improved fuel economy using Shell V-Power fuels has been demonstrated in industry standard and Shell proprietary tests. Actual effects and benefits may vary according to vehicle type, vehicle age, vehicle condition and driving style. No guarantees provided.
Its quite interesting that the fuel manufacturers are very non-comital about any improved economy - they make a inference about it but when you dig into the claim you get whats written above - yet customers can be absolutely convinced about it.
Typically all the manufacturers are claiming is that a clean engine will run more efficiently than dirty one and that their 'super' versions of their fuels container detergents. They don't make any claim as to how much use of their super fuel is needed to clean away and buildup of deposits, but I'm going to guess it's not the moment you turn the key. Is it 10 miles? 10 months? 10 years? Who knows.
So if your engine is full of deposits and putting some super unleaded in will instantly clean it then you might see improved economy (improved in the sense that you'll be returned to you the engines typical economy). But that improvement would continue to be true if you then subsequently use regular fuel from then on too.
But buyers of the fuel seem to believe - even state empirically - that the fuel just conjures extra MPG from nowhere. If it can why don't the manufacturers just say so.
So for the OP - do you suspect your engine to be clogged with deposits? Are you getting poorer fuel efficiency than in the past?
As I understand it, higher octane fuel is less prone to knock or pre ignition.
Cars with fuel injection have knock sensor(s) on the block (along with the other sensors), so can adjust timing on the go.
Whilst true, it's not the octane rating that matters here (unless like @hot_fiat above says, it's particularly highly strung or highly tuned already)... It's the ethanol content, at least as far as economy goes...
Only up to a certain point. Generally will protect as best as possible for lower fuel grades. And "ignore" grades higher than required in the manual. Though you might get slightly better consumption etc. due to different additives.
This... To a degree... But it's also important to consider the following...
Pure Petrol has a stoichiometric ratio of 14.7:1
Ethanol has a stoichiometric ratio of 9:1
Quick maths says that E5 petrol has a stoiciometric ratio of around 14.42:1 and E10 has a stoichiometric ratio of around 14.13:1... Modern ECU's are highly self compensating and you won't notice it happening, but they will compensate for the slightly weaker mixture and use a little more fuel as a result... How much more they will use will depend on how the engine is tuned, but in my experience an engine tuned more for economy than power will probably be 2-3% more economical on E5 over E10, where a more highly tuned engine can be anything from 5-10% more economical on E5 over E10 as well as running more smoothly (but that's often the higher octane rating confusing the issue in modern high compression engines or heavily boosted ones).
Pure ethanol actually has a higher octane rating than any petrol at the pumps ironically, it is 100 or higher RON... So the fact that 95RON petrol has a 10% ethanol content illustrates the poorer quality fuels they use in the mix anyway. "Super" unleaded generally has more high quality additives added too to help keep the engine internals cleaner too.
Is it worth the extra cost...? Only you can do the maths based upon your use case... For my GF's Suzuki Swace (rebadged Toyota Corolla hybrid), absolutely not... For my old BMW M2, absolutely yes (it returned roughly 8% better economy on E5 than E10 as well as running better!)... For my KTM motorbike, it's neither here nor there, I get approx 4% better economy on E5 than E10 on it but the extra cost far exceeds the benefit, so I tend to give it a tankful of super only as and when I can find it for less than 10p per litre more expensive, and it doesn't noticeably run any differently on either fuel.
Our run to the Czech Republic at Christmas was done on Super where fuel was cheaper (UK and CZ). My 3.2l non turbo petrol was 1-2mpg better on Super and is recommended by Porsche.
On anything not intended for 98ron I'd not bother - a good long high speed run with some good hill climbs will clear the engine out nicely.
I've never seen an increase with it in any of my cars.
But on a tank for tank basis frequently find that staying out of Tesco fuel stations does wonders for my mpg in any vehicle ...and in the case of our old transit -prevented it from hunting at idle like it had some kind of pump issue which always appeared after a Tesco fill up.
Potentially yes, particularly if it's hot/high altitude and your at risk of knock/detonation.
However that would only really happen if your pushing it.
In normal use cruising along an autoroute you may find that the adaptations will take longer to happen then you are on holiday for.
Long term use, high performance car or hard use? Yes, it's better.
Putting a single tank in your regular family car that only ever sees whatever cheapest, just to sit in traffic? Pointless.
The Shell thing up there is correct, it's mainly add packs that the general public will benefit from, but will only get the engine/fuel system back to it's intended base. Yes if a car is designed to run optimal with a super, it will like it/learn it and adjust accordingly, but octane number is only an indication of the fuels potential to resist knock, and not all 98s are the same, and your knock sensors will adjust accordingly.
Ref points around stoich ratios, broadly true, but Ethanol is not the only oxygenate used in fuels, so whilst it's a good indication, the lambda s will be looking for total oxygen whether from ethanol or ethers. The more oxygen the leaner the car will run and more likely to knock, the same but in reverse for less oxygen and richer burn. Also, the car power, or rather torque will be governed as well by the calorific value, which in part is determined by the oxygenates, but not only.
Ethanol can be beneficial by ways of a charge cooling effect in the exhaust gas temps which helps to lower oil temps, which can add in reducing blowby effect (very rare in modern cars), but really important in old classics.
Also, back to the point around not all fuel is the same and issue on knock, depending the density, specifically towards back end of distillation range, some fuels can cause wall wetting, which is unburnt /atomised fuel hitting and condensing in the cylinder walls, this contributes to oil dillution, but on long runs is not generally an issue as the sump will vape off through the breather. Wall wetting under extreme loads can also contribute to heavy knock conditions..
Sui, the petrol pump attendant.
I mind ages ago I could only get v power, chucked some 2 stroke in and ran some chainsaws for a couple of days. It stank. Back to the cheaper stuff quick smart.
God, there's some knowledgeable folks on 'ere!
To the question of why Shell won't categorically state it gives x% improvement ... they'd be utterly barking mad to, that's why. It would just leave them open to all sorts of crank (as in weirdo, not the lumpy bar at bottom end of the engine) legal cases and ambulance-chasing law firms. You can hear the radio adds now... "ever had PPI / workplace Injury / a car loan / bought a tank of Super Unleaded since 2007 ? Then call Claims-****ers-r-us on 0800 W-A-N-K-A-Z ..."
the French are still on 95/E5?
Most places we used on a recent trip seem to have both 95/E5 & 95/E10. At a significant price difference too!
short answer yes. anything <20p different and you will be better using super.
I use vpower because its GTL and burns cleaner. I believe (daftly) this is more important on a direct injection engine.
Just got back from a European jaunt - to Venice (ferry to Corfu), then Ancona to home).
I didn't notice any great difference on the tank of super I mistakenly filled up with, getting around 62mpg/600 miles per tank.
It might be more beneficial to "performance" cars, but my 1.0l, 3 pot turbo'd Vitara aint one.
DON'T FILL UP IN SWITZERLAND. 31 litres cost me about €90 at a motorway services. I cried.
To the question of why Shell won't categorically state it gives x% improvement ... they'd be utterly barking mad to, that's why. It would just leave them open to all sorts of crank (as in weirdo, not the lumpy bar at bottom end of the engine) legal cases and ambulance-chasing law firms. You can hear the radio adds now... "ever had PPI / workplace Injury / a car loan / bought a tank of Super Unleaded since 2007 ? Then call Claims-****ers-r-us on 0800 W-A-N-K-A-Z ..."
Except they do claim exactly that for their standard "Fuelsave" unleaded Vs whatever they consider to be the basic spec. As do Esso IIRC.
Which makes me think that it's not true and just confirmational bias. You put a tank of expensive petrol in and get worse mpg; must be because you were giving it the beans. You put a tank of expensive petrol in and get better mpg; must be the fuel. If it really was ~5% better like people are claiming then governments would just be mandating it as an easy win to cut CO2 emissions.
Also there's large variations in base fuel around the country. Some areas E5 will be 5% ethanol, others it's no ethanol because none is available, same with E10. So you could be comparing 10% ethanol basic fuel, to 0% with more additives, to 0% with more additives but still with 95octane, to 5% but 99 octane. There's not an absolute requirement to put 5-10% ethanol in fuel, they just pay a waiver if they don't meet the target for biofuel content.
the one to avoid is E85, unless you are absolutely sure that the car will take it without damage
Sidetracking yes, although where it is available people often tune their cars to run on it as it's got potential to massively increase performance. The trouble is that like E5/E10 there's no requirement to actually make it 85% so they end up having to test the forecourt fuel every time they fill up (it's an easy test, just add 10ml of fuel to water, and measure the volume of hydrocarbon remaining once the ethanol mixes with the water).
Can't wait for E85 to become a thing over here and all the diehard climate change denying petrol heads get their knickers in a twist over the 'green' fuel being better 😂
Since switched to a dirty diesel van (Euro6)
FWIW, I believe euro 6 diesel real world is just as clean as petrol in terms of stuff that is bad for breathing. All the direct injection etc has brought petrol into the world of particulates. Diesel remains much better on mpg & CO2, although obviously being a van offsets that.
short answer yes. anything <20p different and you will be better using super.
I use vpower because its GTL and burns cleaner. I believe (daftly) this is more important on a direct injection engine.
GTL does indeed burn cleaner, but you wont find that in the UK - it's also only diesel - well strictly speaking its EN15940, which is a pure paraffinic diesel, HVO looks broadly the same (which does not look the same as EN590) - you wont (but can) make petrol from GTL technology(Fischer Tropsch), but needs more work/energy to do so, so you normally us FT for JET and Diesel cuts, as well as Naphthas to feed crackers.
Vpower (Petrol) in the UK used to be a single source/manufacture -its not anymore as they rely on the exchange agrements between refiners/distributors to get a base gaoline that is min 98RON then add their proprietry add packs to make it Vpower.
also ref the savings bit - it's all in the small print
" Compared to regular diesel without fuel economy formula. Actual savings may vary according to vehicle, driving conditions and driving style. Internal Shell tests and with our customers have shown a range of fuel savings depending on age of vehicle and type of operations."
or with Petrol save UPTO 1 litre - no specifics, no minimums - just potentials.
We run our 1990 Saab turbo on super at the recommendation of the (meticulous) previous owner. On the odd occasion where it’s not been available, I’ve noted that the boost needle doesn’t make it as far into the red (fun) bit of the boost gauge. Old engine with pretty rudimentary boost control based on a single knock sensor
no idea if it impacts mpg either way
Surprised nobody has linked to this :
Thanks for clearing that up, i was wrong. Doh.
