petrol comparisons

[Scanny]

has anyone noticed improved fuel consumption based on the supplier?
i usually go for the cheapest which happens to be the tesco 2 minutes down the road from me but i put £20 in every 3 days or so. last sunday i used esso and didnt need to put any more in until this morning although i think i still had some in when i got the fuel. it still seems to last considerably longer than the (probably) watered down stuff that tesco sell which would make the extra 2p a litre pay itself off within a few miles
should changing supplier even make a difference on similiarly rated petrol?

[Kryton]

I always use tesco as only place close that sells 99 ron. I found on other cars when driven in a non-progressive way, used to give better fuel consumption that any other fuels, however in the vr4 I agree it doesn't seem too great. I'm assuming that this is down to the car being driven harder so therefor the higher octane fuel will be burnt up quicker. At the end of the day, it is 5 pence per litre cheaper than the shell equivelent so even if you get slightly worse mpg, it will balance out + still better than esso fuel for the car as these are built for jap fuel which is 100 ron

[VR4Kaos]

esso dont do a 99ron tho init shell vpower seems to be better than tesco but i do use tesco due to convinence

[Turbo_Steve]

Much to my amazement, I have found the Tesco 99 RON actually felt smoother, and lasted longer than V-Power. It was worth 2mpg over 500miles, which is actually quite a lot!

[andydckent]

Tesco 99 always feels better and seems to give slightly better MPG than Shell V-Power.

[Kryton]

I agree, tesco fuel all the way. Its just a bonus its cheaper aswell

[Ghost_2008]

Tesco 99 has bio fuel mixed in which is what raises ron to 99. I read somewhere that this actually reduces fuel economy....... proofs in the puidding though....... I always use shell vpower due to convenience, however I used to use tesco 99.......... I couldnt tell you if there was any difference.....

[Nick Mann]

Tesco 99 is my current fuel of choice.

Tesco 95 is, however, sh!t.

Scanny, as you are probably talking about your V6, can you say which grade you are referring to? Obviously, the V6 is designed to be okay on 95 fuel, so it could be that.

[Scanny]

its the 95 i usually put in. i dont actually know what the difference is between the grades. all i know is that the EVO guys use V power and obviously the VR4 owners are using the good stuff too. i put some in occasionally when i am feeling flush and decide to put some better fuel through the system regardless of the fact that i dont understand what makes it better

[Nick Mann]

Octane rating is fundamentally a measure of how much energy is stored in the petrol. A higher number means higher potential, although not all cars will be able to make use of it.

I'd advise to stay away from Tescos 95. All normal petrol cars I have run on that grade have run badly and inefficiently compared to Shells 95 offering.

The only way to get a true idea of actual MPG's is to fill the tank to the brim every time and check your actual mileage. Any other way is not particularly scientific.

[martin_y]

Octane rating is fundamentally a measure of how much energy is stored in the petrol. A higher number means higher potential, although not all cars will be able to make use of it.



I havent checked Wiki, but I thought the Octane rating was a measure of how stable the combustion is, and more importantly, the likelihood of knock, or detonation? (the higher the number, the less likely)

[Nick Mann]

I havent checked Wiki, but I thought the Octane rating was a measure of how stable the combustion is, and more importantly, the likelihood of knock, or detonation? (the higher the number, the less likely)

You are absolutely right! Well - I've learned something new today.

I can't explain any longer why Vickys old car was so much more efficient on 98 than 95 though.

[martin_y]

Ok, well if the 95 starts causing knock, the Car will retard the timing, and now you're running the engine at less efficiency. That means 98 could be more economical?

[Nick Mann]

Aye, but it was a peugeot 2.0 with a claimed power output of 137bhp. Not really an engine to suffer from knock?

With optimax/V-Power, it would run smoother, become more responsive (not sure I'd term it quicker, but definitely more responsive) and would return better MPG.

Tesco 95 (Or Sainsburys) was disastrous when compared with Shell or BP 95. The effects of V-power were reversed!

Running V-Power for a tank also improved the results of the 95 for the next few tanks too - almost like it had given the car an Italian Tune Up!

[martin_y]

Theory would be..

We could imagine that the cheap petrol causes carbon build - up which would contribute to knock. So the timing gets retarded. Then the BP and Shell come along and clean it all out, and the timing can advance again without knock.

[orionn2o]

You are absolutely right! Well - I've learned something new today.

I can't explain any longer why Vickys old car was so much more efficient on 98 than 95 though.


Although they are not directly linked, it could be that the calorific value of the two fuels were different as well as the Octane rating. Which as you now know is really a rating of its ability to not detonate without a spark.

Of course Martin's theory could be value, but I'd only expect that issue more on higher output engines

[Scanny]

i put tesco 99 in this morning on my way home so i will see whether or not the car likes it. it is ultimately the cars opinion that is the deciding factor on what fuel to use

[Turbo_Steve]

There's a host of factors involved in petrol quality, not least the rate of usage of the car in question - if you've got a petrol car that does 10,000mpg (i.e. brads) then the fuel is going to sit in the tank a long time and degrade.

Different fuels tend to have different "weights", so some will flow through the pump / injectors better.

The aromatics can make a huge difference to the way fuel burns.

[Scanny]

i noticed there is no mention of bp. since most of the petrol stations are near my travels i would be interested in opinions. i have always used them to gain nectar points but i am tempted to try shell now that i have discovered one at the other side of town. i did always notice a difference with shells pre V power (cant remember what it was called) petrol in cars i used to have

[Turbo_Steve]

Optimax was (IMO) better than V-Power is.

[Scanny]

thats it. cheers Steve. when i fancied a blast i used to put a tenner of optimax in the tank with a bottle of hot shot

[Wal]

Old thread resurrection, I've been putting Sainsburys super 98 Ron in as it's convenient location, should I be going out my way to tesco for 99 ron or find a BP etc?

Wouldn't of thought it would make much of a difference but might as well ask!

[funkstardelux]

not really as the ecu senses its lower ron and adjusts itself.

[viniu88]

been to see Nutter on sunday ... fill up tank with V-Power ... go to his and back (made 260miles) ... pop in to same petrol station, and top up again ... 41.47 liters ... 90% motorway but still not bad :)))

[horndog]

http://www.thorneymotorsport.co.uk/tuning/Fuel_Test_Results_Update.shtml

This is an interesting read - if your into that sort of thing.
But, Note that Tesco sponsor Thorney so I cant say how impartial it is

[low_vr4]

isnt Tesco a supermarket chain? do you have supermarket fuel like we have here. e.g. paknsave fuel etc?

[Ryan]

isnt Tesco a supermarket chain? do you have supermarket fuel like we have here. e.g. paknsave fuel etc?

Yes.