Petrol - Supermarket vs. Branded

bunking_off

Sorry regulator, but agree with the earlier posters that you're wrong.

98/99 RON fuel will only make a difference if the vehicle is tuned to run on higher octane fuel and manages on lower octane fuel via retarding the ignition (ie as Tom says adaptive ECU). I differ from Tom a little in that my understanding is that every modern car has this, it's just that many will be set with 95 as default (e.g. in some countries you can get lower RON fuel than 95, so they need to adapt to cope with that).

It does tend to be higher performance engines that are setup to cope with higher RONs than 95 and retard back when on 95, but usage of a turbo charger or otherwise has nothing to do with it. My current car has a supercharger, and as posted earlier does not particularly get on with standard fuel. I had a Porsche at one time, which had a 2.7 normally aspirated engine, and similarly it was setup to run on 98 but could cope with 95 if need be.

Personally, I think that putting V-Power in a run of the mill family car is a bit of a waste, but given the price differential between standard 95 RON Shell/Esso and supermarket fuel (typically in this area zero pence, if you ignore the vouchers they give out at the supermarket) then it's worth the trouble of getting the branded stuff.

regulator_2

As I said before, check on Tyresmoke as the link to the article is on there.

tomstickland

You originally said

It only actually works if your car has a Turbo engine

ie: you said "it only actually works", when what I think you really meant was
"you'll only feel the difference" or "there is more difference".
High octane fuel will only make a few percent difference, and 1% of 150BHP is 1.5BHP.
On a turbo car where they operate lower geometrical compression ratios but have boost and higher inlet temperatures, I agree the difference will be more worthwhile.

regulator_2

tomstickland wrote:

You originally said
ie: you said "it only actually works", when what I think you really meant was
"you'll only feel the difference" or "there is more difference".
High octane fuel will only make a few percent difference, and 1% of 150BHP is 1.5BHP.
On a turbo car where they operate lower geometrical compression ratios but have boost and higher inlet temperatures, I agree the difference will be more worthwhile.

Let me start again. Optimax etc will work in a normal petrol car. However, there will apparently be no gain from it in a car other than one which contains a turbocharged engine.

Now, Tom, you say that it will make a 1% difference, if thats an official figure, the website may have left it out as 1% is not really a significant gain. However, as you rightly said the benefit received from optimax etc in a turbo charged car will be more worthwhile.

Wirenth

I've got a perfectly ordinary diesel car and fill it up with....perfectly ordinary diesel. I'm also quite sad in that I track my weekly mileage and litres put into my car.

Supermarket fuel gives me 55ishmpg and shell 61mpgish. I've noticed a difference in engine noise when I fill it up at supermarket v.s. Shell.

Hasn't worked with Texaco or BP fuel, but I don't use those often and it may be an anomaly caused by the 'trip setting' on the pumps.

tomstickland

Let me start again. Optimax etc will work in a normal petrol car. However, there will apparently be no gain from it in a car other than one which contains a turbocharged engine.

Now, Tom, you say that it will make a 1% difference, if thats an official figure, the website may have left it out as 1% is not really a significant gain.

1% was a number I made up - there's room for a few percent improvement from octane.