Porsche Enthusiasts Club Forum

Tesco 99's imrpoved knock resitance comes from the ethanol thats added. Its good for increasing the RON number but it has a less energy. The Greenergy99 fuel is usually better for turbocharged cars and some NA cars that will benefit from the ignition advance; and which will see a benefit in excess of the power lost trhough the lower calorific value.

Normally aspirated cars will see a greater benefit by using Shell V-Power, or even Esso SUL etc... One further point: you cant expect to see an improvenet through advance immediately. The ECU will retard quickly, but without re-setting most will only advance very slowly and many not at all (this may not apply to old Porsches though, because the Bosch Motroni DME was used on the Ark's backup engines!).


Simon

Lower calorific rate? I didn't want dieting advice. I only asked if V-power or similar would improve mpg!

Ben

low fat petrol, wont that give lean burning ?

This is discussed fairly often, and I always find my experience doesn't mirror the majority view.

My S2 returns about 10% better fuel economy with high-octane petrol (Tesco99 or Shell V-power), which makes the pence/mile calculation pretty much identical to that when using standard petrol. (I monitor fuel use very closely for a number of reasons, so am confident that this is the case.)

What I also notice with the 'premium' fuels is that the engine is smoother and the throttle response crisper. It feels 'quicker', and I prefer the way it drives.

For my money, it's worth every penny.


Oli.