Fuel Quality

[DC]

I know this has been discussed before but what a difference after filling up with non supermarket fuel!
I've succumbed to a few 5p off vouchers for Tesco fuel in the last few fill ups and gradually come to notice a drop of in performance though I thought I was imagining it.
Being low on fuel today I filled up at my local Torq filling station (can't always get the main brands in these parts).
After a few miles there was a definite difference, particularly with the auto gearbox which doesn't hang on to the gears as long and changes up more readily, tick over is also smoother.
This on a simple M44 which I wouldn't have thought would benefit so much.
Dave.

[OldskoolRS]

I used 95 RON unleaded when I first got my 3.0 not knowing any better. After I replaced a camshaft sensor I reset the ECU and filled up with 98 ROM super, but TBH it doesn't seem to get any more mpg as some claim, though it goes very well it's hard to tell which bit is down to the new sensor and which is the fuel, but I'll carry on using 98 RON I reckon as it's not much more money.

[geminimustang]

we live near the stanlow oil refinery and watch the supermarket tankers drive in to be refilled along with the Shell tankers,all in the same queue.Difference in fuel quality? I believe there is but i haven't worked out how ! someone will be along shortly and explain,i'm sure.

[XVar]

Apparently the difference is due to addatives in the non-supermarket fuel, at which stage they're added I don't know. I use Shell V-Power in the Z because I only fill it up once a month, but use Sainsbury's diesel in my 307 and get 55mpg+ so the fancy diesel would be pointless expenditure.

[Del]

I agree with geminimustang, my brother-in-law was in the petrol industry and has always maintained that the same wholesale storage tanks from the main stores, supplied all garages. As far as I know there is no difference.

[swamper]

there are differences that iv noticed as well.......i put V power in 99% of the time but sometime i have to fill up elsewhere..V power the M runs smooth..BP super unleaded lumpy as hell..it really doesn't like it!

[maurice the martian]

Tried both fuels and to be honest not noticed any difference in performance or mpg 3.0ltr Z4.
Mostly run on Morrisons cheapo fuel, put my foot down and it flies
M

[Mike Fishwick]

UK petrol is not of very high quality, and of course in many areas anything over 95 octane is impossible to find. Here in rural France, I generally use our local supermarket's unbranded 98 octane, which is fine, and when comparing it (in terms of fuel consumption at given speeds) during trips tothe UK I find that Esso - in 95 and 97b octane types - is the best. V-Power was no different than anyone else's 97, and the last time I used it (in France) my fuel consumption on the autoroute increased from about 34 mpg to 28 mpg - probably due to an overdose of ethanol. Ethanol is a good - and cheap - anti-knock agent, but a very poor fuel, hence the poor fuel consumption. In France we have specially-labelled 'E10' (10% ethanol) pumps, whereas in the UK no-one is quite sure of the ethanol content.

It's the same with diesel - sometimes a 10 mpg improvement when using French fuel.

You will find - if you read the handbook - that the M44 1.9 engine is rated at 140 bhp on 95 octane, but will deliver more power and better fuel consumption on higher octane fuel, so it is not surprising that the OP noted an improvement. On my 2.8 I usually reckon to see a 10% improvement in fuel consumption when using 97 octane, as compared to 95.

A friend, who was the manager of the Conoco depot in Plymouth, told me that after the common-use petrol was put intothe Shell tanker, the driver filled a big paint tin withthe magic additive, and poured some into each of the tanker compartments - the last compartment therefore received less of more than the others, and there was no precision in the dosing at all!

[geminimustang]

I've a golf diesel for a company car and cover 40k miles pa. so fill up at least weekly.Tesco diesel gives my worst mpg,Morrisons the best though their bio-diesel is supposed to be a no-no,i haven't figured that out.The argument is Morrisons diesel cleans the fuel system and can push gunge along the fuel system creating problems.Not with mine! Shell super-duper diesel does give extra mpg but i find it only covers the extra cost so i don't get any financial gain.I don't buy into the UK poor fuel argument as i don't believe anybody makes poor fuel but i do accept some fuel is better than others but how you find a definitive answer,i wouldn't know.

[Mike Fishwick]

I am speaking as I find - in terms of mpg the fuel in the UK is well behind that of France, Germany, and even Spain. All countries do not have the same fuel mixture, the UK permiting a far higher proportion of Benzine than others, and an unspecified amount of ethanol.