What grade of fuel should I use?

[Tomba26]

What grade of fuel should I use? The manual says; refer to the filler cap, it states 95 and 98! Any views?

[worldwidewebs]

Always put super-unleaded in (the higher the octane rating, the better), unless you have no choice

[Carguy44]

Tomba26 said:

What grade of fuel should I use? The manual says; refer to the filler cap, it states 95 and 98! Any views?

You ask which type of fuel to use, but you then quote what the manual says?!

Who knows more about the car, the engineers who made it, or some random person on here?

[bram070]

The salesperson at 'my' Alpine Centre recommended just to use regular Euro 95 petroleum, which is what I do. I try to avoid cheaper brands though, as my Mazda seems to run remarkably smoother on Shell or BP.

[bcr5784]

I think it is an EU requirement that all cars are able to run on 95 octane. That doesn't mean to say they run best on 95. I certainly find pick up at low revs is better with 99 octane so I always run on that if it is available.

[Martyn P]

I prefer to use 99 fuel for the possible extra performance and the fact it has less ethanol. I also try to get Shell v power as the additives help keep the engine clean.

Is it worth the extra? Not sure but it makes me feel better!

[essexstu]

As stated in the manual you can use either 95 or 98/99 Ron. You'll obviously get slightly better performance from the higher octane fuel.

[bcr5784]

essexstu said:

As stated in the manual you can use either 95 or 98/99 Ron. You'll obviously get slightly better performance from the higher octane fuel.

To explain that a bit (grandmas capable of sucking eggs need not attend) - the compression ratios that modern engines (even turbos) use are far higher than in days gone by. The higher the compression ratio the more torque/horsepower the engine will generate. However that may cause pinking/detonation which will damage the engine. So engines have "knock" sensors and if the ECU detects pinking then it retards the ignition - reducing power. The higher the fuel octane rating the less the engine is likely to pink, the less the ignition will need to be retarded and the more torque/horsepower the engine will develop.

As result a higher octane fuel will give better economy, if the engine is optimised to use it Whether that itself justifies the extra cost is debatable.

Edited by bcr5784 on Monday 5th December 19:17