Recommended fuel

Just so I don't do something silly on the way home after collecting the car on Saturday What is the handbook's spec for the fuel used in the normally aspirated 3.6? (I've been using diesel exclusively for the last two years - I'll have to be soooo careful)

Shell V-power is all I'll ever use in the UK... More expensive but you also get better mpg. :thumb:

Super unleaded is recommended, although it can adjust to normal unleaded if you find yourself in the wilds and can't get any. I've seen mucho debate as to which brand is the best, some folks have a thing for Shell* but I personally don't differentiate as long as its one of the "majors", and even that is probably me being naive. As you say, I think diesel would be a bad idea in general! * ETA - see, even as I'm typing there's a vote for Shell. Not saying they're wrong, just I haven't noticed a difference.

You can run 95, 98 or 99 RON. 98 or 99 is supposed to get better performances. When switching from one RON to another, you will need to put it through the tank a few times, to allow the ECU to detect the different fuel type. I find that the supermarkets actually provide the best performance and I don't really see any difference between Shell, Texaco, Tesco, BP etc. I am actually very, very skeptical about the entire 95 versus 98 RON argument and the associated power gain/better mpg - versus the additional cost. But, as I don't pay for my fuel directly, I haven't really investigated this a great deal (only a few times, where 95 RON has been the only option) - but when I had to put 95 RON consistently a few times, I couldn't feel any difference and there was extremely limited mpg difference - certainly not justify the price difference. Best to experiment and see what it averages out at.

There was a comparison done not so long ago on 'Fifth Gear' IIRC showing 3 different fuel grades and manufacturers on 3 different types of car, ie small domestic, family and sports (again IIRC). It showed a marked improvement in mpg and bhp/torque when using Shell in a tuned 'sports' car... The none sports models didn't care what fuel you gave them... Like you say though this topic has been done a million and 1 times. I use Shell as it was recommended by my Indy, others don't. AIMHO ofcourse... :thumb:

http://www.911uk.com/viewtopic.php?t=31033&highlight=fuel

All petrol, with a few exceptions, comes from the nearest distribution point, which comes from the nearest refinery. So every Shell/BP/Sainsburys/Total petrol station in YOUR area will be selling the same petrol.... the exact same petrol. The only difference is the additives package that is added into each tanker when the tanker is filled at the distribution point. One of the exceptions, DEPENDING where you are in the UK, is Tesco, who source most of their fuel from Greenergy, who get their fuel from europe, rather than any UK refineries. To answer your question, your car benefits from higher RON fuel, so try out some different superunleadeds and see which one works for you. Most are 97 RON, but Tescos and Shell are 99 RON. BP Ultimate can be higher. As Harry said, 95 RON won't do any harm.

That's an interesting one, I have in the (recent and not so recent) past thrown the C2S a bone in the shape of a tankful of the costly stuff. I'm now wondering whether it's worthwhile after reading the latest "Bike" magazine. They put 3 sports bikes on a dyno after draining and brimming the tanks with normal and premium fuels. IIRC, 2 of the bikes produced less power and mpg with the premium fuel and one bike produced marginally more power (were talking one or two tenths of a bhp) and less mpg. I'd be interested to hear if anyone here has conducted a similar test. :bye:

Roy - if your ECU is able to adjust for different RON, the results can be large. http://www.thorneymotorsport.co.uk/tuning/Fuel_Test_Results.shtml It is clear from the testing that whilst older engines show a clear benefit of running higher octane fuel, more modern, sophisticated engines have the ability to advance their fuel timing to take full advantage of this enhancement to a far greater degree. For the BMW M3 CSL the difference between running 95 octane fuel and Tesco 99 Octane fuel was over 40bhp, that's over 10%. And here, for your further reading pleasure, is V-power vs Tesco99 vs BP 102. http://www.thorneymotorsport.co.uk/tuning/Fuel_Test_Results_Update.shtml

Call me a cynic but.. And the team's top sponsor (partner) is.... :?: Ta-Ra! Tesco 99 Octane Fuel

I only put the Super or High Octane Unleaded in the Porsche as I use it a lot less than the Jag. I did notice this weekend though when filling the Porsche that the price differential is now vast (I haven't really payed any attention to fuel prices in ages - Comes from driving a 4.2 V8 Supercharged Jag). The regular Unleaded at the local Texaco was 111.9 and the Super was 129.9 Is this something just to this petrol station or is there normally an 18p price differential per litre?

This was posted just after I had completed a 2,000 mile trip around the British Isles. The car was not as responsive in Scotland/Southern Ireland where all I could get was 95RON. It took a few tanks of VPower to get it back to normal.

I've never seen Tesco be anything other than 5ppl difference between 95 RON and 99RON.

Don't forget the point of the original test was to show the difference between 95 and 'super'. In the follow-up superunleaded-only test, don't you think they could have 'fixed' the results much more clearly if they'd wanted to? And as a race-team, don't you think they would have switched sponsors if the fuel was better? :grin:

I have always put Tesco 99RON in my Porsche. Best to support the company I work for, get some priviledge points and help the profit sharing scheme.