Porsche Enthusiasts Club Forum

As the title says really. I know there has been discussion on this in the past, but the answers are confusing - of the "Porsche says it needs to be 98, so how can you say you know better" to "I've always used normal fuel and it's fine" variety!

I'm confused!

In around 7 years & 46K miles mine was run on standard Unleaded albeit either Shell or BP. The few times I tried super unleaded it made zero difference. Mine was a 87 2.5 the same as yours.

Always good to have the debate, lots of crap talked about when it comes to fuel. I sell millions of litres.

Fuel is not all the same, despite what some would have you believe. The higher octane fuels burn better and the branded fuels have much improved cleaning properties.

Supermarket fuel is often the lowest common denominator, depending on which terminal is supplying it.

MPG is also dependent on where the fuel comes from and although the differences are quite small. Hot fuel can shrink by as much as 3%.

I agree Sean, and always go for the best having tested regular supermarket against Shell V Power, Tesco Momentum and BP Super etc on Racing engines
for many years, all the super 98 & 99 and even 97 provided more power and torque & a better burn than any standard 95.

I also hear the basic 95 has less tolerances and more moisture (water) content is allowed in it, to the point where if its too low water gets added!
The higher octane fuels have different BS numbers and have to be more accurate to their RON figure.

Many car magazines have done dyno tests and found more power with the higher octane fuel, however this is not massive and not always noticeable
in some cars that are either a small capacity or an inefficient design (Not twin cams)

I've always got better MPG with the higher octane fuels even in a daily 2.0 16v Focus.

As Sean also mentioned the additives in the more expensive fuel also are a benefit.

R

It's worth repeating this link from the PCGB 944 forum:

https://www.porsche.com/uk/aboutporsche ... 23-classic

Whilst the 944 is quite high compression it doesn't have knock management and feedback so cannot adjust the ignition advance to suit petrol quality and engine conditions. Therefore it may not benefit from super high octane fuels.

The point is super unleaded is only 5% ethanol, and Porsche state 10% ethanol (which 95RON unleaded increasingly is) is not suitable for pre 1996 cars.

Both excellent points, Jim and Jim.

My 944 S2 now runs on super-unleaded as it is fitted with a Promax ECU upgrade chip which does benefit from the use of super-unleaded and to avoid the E10 trap. Prior to that being fitted, the car ran for several years very contentedly on 95 RON Premium.

Even my '73 Beetle gets V-Power these days, for this reason.

Michael

Just back from hols and caught up on this - thanks for all your advice.
Howard

My daily 24 always gets the good stuff.

All 3 cars I've got with a turbo get super, bike gets it too.