Fuel type for a E36 M3 EVO

[motormania]

A colleague at work has just purchased a R reg (98) M3 Evo and the guy he has bought it off says that he should ONLY use Optimax or a high octane fuel in the car. The car has no modes and is exactly as BMW built it.

Will the engine be damaged in any way of he uses normal unleaded, rather than the higher Octane fuels.

Your assistance will be gratefully received, thanks.

[David1975]

Its should not damage the engine in anyway although you may not be getting the most out of your engine. I will probably state something similar in the manual.

In there it will give the optimum RON grade and also the minimum ron grade which will be well below our stty 95 RON std unleaded.

I hope this helps

[neil_bolton]

Not the same engine, but I've developed an understanding with mine that 1 in every 4 tanks will be Optimax, and it seems to keep her running reasonably well - she certainly pulls harder after a tank of Optimax, and you can feel the mapping readjust slowly back to normal fuel on subsequent fillings.

The Optimax/Cheapo fuel ratio above seems to keep the car happy

So as such, it doesn't damage it in any way, but you'll notice a difference if you stop using it - most notably slightly better off

Edited by neil_bolton on Thursday 3rd July 13:14

[wpo750]

I always ran mine on Super unleaded and it does state on various places in the car to do so, the car is mapped to run on high octane to it would be rude not to. Mine was remapped and seemed to run best on Tesco 99, had tendancy to run a bit rough on Optimax/V-Power. The car is fitted with knock sensors so you'd get away with running it on 95ron but as said you'll not be getting the best out of the car and I wouldn't recommend it.

[andye30m3]

I used to run mine on normal unleaded but it does seam to go a bit better on 97 or 99 RON so that's what I'd advise he uses

[swansea v6]

When I had my 325i coupe (not quite an EVO I know!!!) I emailed BMW and asked what octane fuel I should use. They replied with a VERY descriptive email, explaining that all their performance engines were designed and dyno'd using high octane petrol. It is ok to use the lower octane stuff but you would get slightly less performance and worse fuel economy. if I can find the email i will post it up.

[dan101smith]

There's a sticker on the dash over the top of the fuel guage stating that you should use 98RON fuel - tell him to stop being cheap, and stick some of the good stuff in it.

And yes, it does make a difference to performance and economy.