Fuel type

[craig green]

Does anyone genuinely feel a difference when comparing 95 RON fuel to say BP Ultimate etc?

Sometimes Ive wondered if it was worth the difference in cost. Maybe it is better & perhaps just using the odd tankfull here & there is no good if there is already a considerable amount of Supermarket fuel already in the tank.

Comments.

[Dar]

I never bother. I've used the higher octane stuff before and have never noticed a difference. However I think it has more benifit for the turbo engines. Not for power as such but to reduce the risk of detonation.

I have had mates who said they noticed a difference though. So I guess its a suck it and see. Im sure that you have to get the car tuned to the particualr octane fuel to get the real benifits. But then again I maybe talking out of my ass (I've never really looked in to it).

[Beany-Germany]

With normal engines you can use the normal 95 octan fuel. With XE or LET Engines or tuned small engines you should use 98 octane fuel. Only if the controler has optimised data sets for 100 octan fuel, you should drive it. Otherwise there will be no measurable effects.

They only want your best... Your money!

[Lee]

A higher octane fuel is always better than 95 RON. V-Power at 99 RON will be better than 97 RON (Super Unleaded). Cars mapped for the fuel will benefit from a higher octane. Also on a track day where temperatures are usually higher there will be an additional benefit from a higher octane fuel, with less chance of pinking.


The higher octane fuel burns cooler than 95 octane fuel which means cylinder heat temps (EGT's) are reduced, therefore the ecu can put in more ignition advance and produce more power (simplified version).

[dannyb]

No difference in my carbed 1.2, I just run it on anything 95 octane that isn't supermarket fuel. The BMW used to get better economy on optimax and the Corrado 1.8 16v a mate has runs happier on 97+ octane fuel, as does a mates EVO VI

[Stuart]

no difference in my VX and thats got a far more sophisitcated setup than an XE lol.

unless your engine can advance the ign to suit the higher octane you can potentially LOSE power due to higer octane fuel taking longer to burn which can push peak cylinder pressures past the usefull point and also keeps heat in the system longer so could also burn out exhaust valves if its "that" bad

[garyc]

Shell have now replaced Optimax with V-power a 99 octane fuel. Tesco also sell a 99 octane fuel.

[Stuart]

i ran a tank of tesco 99 in the omega once... NEVER again. it ran shagigng hot and gained nothing lol

[Welsh Dan]

I noticed no difference between 95 and 97 ron supermarket fuel, or between 95 and 97 ron esso fuel in a tired old 1.2, but I notice a massive difference between 95 ron supermarket fuel and 95 ron shell/esso/bp. I dont buy supermarket fuel anymore.

[Adam]

I've never put any other fuel in mine apart from 95ron BP.
I've only got a 95 Ron plug too, so buying 97. Ron would just be a waste.

[bump]

Just to let you know that supermarket fuel and BP/Shell/Texaco is all idenical RON for RON. Supermarkets just sell it as a loss leader, hence the cost diference as they can prop up with other sales, any difference is purely psycological.

[letmelive]

i used it in my motorbike all the time and there was a power differnece. also in the nova yes it does make a differance.

[dannyb]

Supermarkets draw their fuel from a number of different suppliers, the Tesco filling station on I used to work at bought in fuel from Shell and Esso. The supply of fuel by all these suppliers is more inconsistent in its quality as some of it has been standing about and 'goes off' (i.e the fuel oxidises) despite the additives to slow this process. Some supermarket fuel is as bad as some other suppliers fuel though. I buy from Shell as their petrol station is very busy and there are regular deliveries of petrol, thus eliminating the chance of buying old petrol. And its only 89.9p/litre at the moment compared to Tesco's 92.9p/litre!

[Lee]

Just to let you know that supermarket fuel and BP/Shell/Texaco is all idenical RON for RON. Supermarkets just sell it as a loss leader, hence the cost diference as they can prop up with other sales, any difference is purely psycological.

Not true, there are actually a lot of differences in the additives used in the different branded fuel. and RON actually stands for Research Octane Number, and is tested under very simple conditions which means the test boundaries are quite broad.

[craig green]

Aye. Isnt 'MON' the rating that should be looked into. Its all way technical, but I know that fuel goes off very quickly these days due to substances being banned etc. (lead/benzine)

[Lee]

Indeed pal, Motor Octane Number (MON) is measured under tougher test conditions and at higher engine speed and temperature. The average of RON and MON is what becomes related closer to actual driving conditions, and this SHOULD be what the fuel sellers advertise, however, if they have a fuel with a higher Research than Road value, they will slap that on the pump instead lol

Hense why they are definately not all the same!

[bump]

I'm no expert, I was informed by a friend of mine that has run a group of filling stations for 50 years.

[Welsh Dan]

My mum could tell the difference between the way the car ran on sainsburys fuel and on shell fuel, before I told her why lol.

[Philsutton]

my corsa barely runs on the low octane stuff, sadely i have to fork out on the expensive stuff

[Lee]

I'm no expert, I was informed by a friend of mine that has run a group of filling stations for 50 years.

lol, me neither, but i remember a conversation I had with a guy who works for BP (while i was fitting a rear pro unit in one of their boardrooms)

At least it makes me look mildly intelligent lol

And Phil.. mines the same, i get Det if i run on 95. Thats what you get for running a silly compression ratio lol