How picky are cars on fuel?

[twoblacklines]

So been using shell vpower a lot lately and cars been running great. Found myself in Callington earlier, with 25 miles of fuel left and red light on. Tesco up the road, nearest Shell garage about 50 miles away. Put in £50 / 3/4th a tank of Momentum 99.

Immediately I can tell the car has lost power, and about twenty miles in it is misfiring all over the place.

Could this be bad fuel? Could my bmw just not like tesco fuel? What can I do other than flushing out £50 of fuel somehow and replacing it with vpower?

[carreauchompeur]

I think they *can* be.

I normally run my E36 M3 on Momentum as it seems to perform best on that. I've put the new VPower in a couple of times and there's a definite lumpiness which I don't like at all.

However it also seems to run absolutely fine on standard 95 from Esso, so I generally use that now.

[Fort Jefferson]

My K5 GSXR 1000 was awful if I put anything "super" in it, normal unleaded it was fine.

[ChocolateFrog]

mrf said:

Prob crap in the fuel filter from being run so low.

In 3. 2. 1.

[framerateuk]

I've never noticed any difference between petrols on any of my cars.

[PositronicRay]

mrf said:

Though ONCE I've had fuel issues, borrowed my mums 12 plate rio to get a part for mine, filled it whilst at ASDA in Dundee, coming home, gave it the beans coming onto the dual carriageway, shifting before the red line....check engine light came on....pulled over, turned off and then restarted...issue gone...but never bought fuel at asda since....

That's conclusive then.

[PositronicRay]

twoblacklines said:

So been using shell vpower a lot lately and cars been running great. Found myself in Callington earlier, with 25 miles of fuel left and red light on. Tesco up the road, nearest Shell garage about 50 miles away. Put in £50 / 3/4th a tank of Momentum 99.

Immediately I can tell the car has lost power, and about twenty miles in it is misfiring all over the place.

Could this be bad fuel? Could my bmw just not like tesco fuel? What can I do other than flushing out £50 of fuel somehow and replacing it with vpower?

I've never experienced any problems with fuel, if a car is optimised for a higher octane it just won't perform quite as well on a lower octane. Pretty marginal really.
Are you sure the problems aren't related to the ones you had when you purchased it a few weeks ago? A normal production engine won't misfire just because of a lower octane fuel

[NotReallyBored]

My old Legacy 3.0 used to pink like crazy and hate starting on Tesco, basic unleaded or the higher octane guff. Shove some BP/Shell or Esso in, purred like a erm.... Subaru. tried this several times too, not just a one off.
Never really experienced this before with the other cars/bikes (most performance, but no need to say what on here) I've had, just thought it was forum piffle, never used Tesco again.

[McSam]

Many don't realise that Tesco's Momentum 99 fuel has quite high alcohol content, part of the reason it achieves such a high octane rating at reasonable cost. It's generally 5% ethanol and 3% methanol. Many older fuel systems won't like this, but modern cars shouldn't have any problem with it.

I seem to remember reading that BP Ultimate is has the lowest alcohol blends of the super unleaded fuels available in the UK, but I'm not sure if that would still be the case today, as increased ethanol use is being encouraged by the EU.

[S4mb0x]

twoblacklines said:

So been using shell vpower a lot lately and cars been running great. Found myself in Callington earlier, with 25 miles of fuel left and red light on. Tesco up the road, nearest Shell garage about 50 miles away. Put in £50 / 3/4th a tank of Momentum 99.

Immediately I can tell the car has lost power, and about twenty miles in it is misfiring all over the place.

Could this be bad fuel? Could my bmw just not like tesco fuel? What can I do other than flushing out £50 of fuel somehow and replacing it with vpower?

A lot of people will say it's placebo, but I fully agree with you, but in reverse.

I used to use M99 for the Clubcard points but got fed up that Tesco never had any in stock, so on the next empty tank after I switched to VPower and my car instantly felt better in every aspect. Didn't have huge gains in MPG, but roughly 10% improvement (~30 up to ~33 MPG.) But the throttle response felt better and it picked up a lot nicer. I've been using it since. Shell are meant to have better additives than most though.

I'm sure plenty will disagree. Each to their own though!

[MagneticMeerkat]

I don't understand this attitude - really I don't!

I have, being a monetary minnow, owned cars where this actually makes a difference. Or at least should. Cars with manual chokes, funny carbs, mechanical fuel injection (really, fully mechanical fuel injection). Cars that should be run on leaded, cars that only run on unleaded, cars that run on both.

I have filled all of them at numerous petrol stations and noticed, erm, no difference whatsoever.

A modern car has an ECU to control fuel injection and ignition. It can, and does, do all sorts of far out stuff like adjust the timing on the fly to compensate for variance in fuel quality. You really shouldn't be noticing any kind of difference.

Have you considered the placebo effect? It is fairly strong when it comes to this sort of thing.

[Hainey]

My BMW gives about an extra 3mpg on vpower or ultimate and seems so much more happy to rev than it does on the normal shell or bp offering. Give it ASDA special and it runs like a dog and it will eventually throw up an eml with a p code indicating that the o2 sensor is goosed. Put the good stuff in, clear the code and it's fine again.

Same with the volvo diesel hack. Put the good stuff in it and it's noticeably smoother, quieter and more powerful. It also has the rep from my diesel mechanic of protecting my pump and injectors.

[J4CKO]

I only put Shell Super (whatever they call it this week) in my 350Z but it is like feeding the Cookie Monster "Taste the Difference" Choc Chip biscuits, it all gets guzzled quickly.

[DaveH23]

Fifth gear do a good test here with a variety of fuels but would of been alot better if they tested it on different engine types.

Would of been interesting to see old vs new vs NA vs turbo vs supercharged etc to see which engines respond better to the different types of fuel.

https://m.youtube.com/watch?v=WTaBngvsPrc

[GregK2]

J4CKO said:

I only put Shell Super (whatever they call it this week) in my 350Z but it is like feeding the Cookie Monster "Taste the Difference" Choc Chip biscuits, it all gets guzzled quickly.

I like the analogy

[belleair302]

So long as the petrol station is busy I will put in anything. Fuel does go 'off'. Put V Power into the Lexus if doing a long journey, 300 miles plus or every third tank which is once every two months.

[dog man]

I've always presumed that supermarket fuel is lesser quality but in a normal car you wont notice. Name brands like Shell etc have better additives. V power in the E46 M3 all the way.. V power in the ZX12 R - I cant say I notice anything but to fully notice you'd have to thrash it which isn't as easy as you think.

[skyrover]

All modern car's are fitted with knock sensors... ergo will run fine on any fuel sold in the UK today.

[daveofedinburgh]

One for petrolhead sacrilege thread here...

Ran out of petrol on my way into work one morning in my 2.0 Z3 (as if the shame of driving a Z3 weren't enough already).

Had about a mile left to go, car cut out and wouldn't start. Remembered I had a bottle of Redex fuel system treatment stuff in the boot, whacked in half a bottle out of desperation (I know, Im sorry).

Car ran perfectly to work, same on the admittedly short dual carriageway run to the petrol station at lunchtime.

No ill effects since, fuel system must be super clean I guess...

Naff all to do with how picky cars are on different grades of fuel really, but I found it amazing that it even ran.

[BritishRacinGrin]

I think Redex is mostly paraffin isn't it? Certainly smells like it. Paraffin and snake oil.