Running 99RON fuel

[Kinky]

I've been looking at the Shell V-Power ads, and it got me wondering if my 5 could run 99RON fuel without any retardation.

Anyone running theirs? Any advice? Or is it simply a case of filling up and off you go.

K

[Herman Toothrot]

what do you mean? 99ron like the tesco stuff allows you to run more advance.

[Kinky]

H - I guess any 99RON fuel ... is there a difference between the tesco/Shell/etc/etc fuels?

K

[Herman Toothrot]

I'm not sure what your asking, you can put whatever petrol in, however it may make no difference if the cars not setup to make the most of the higher octane, i.e. running more advanced ignition than stock. Japanese imports maybe able to make better use of it than uk cars.

[Kinky]

Herman Toothrot said:

Japanese imports maybe able to make better use of it than uk cars.

That's the key I was looking for.

I wanted to know if the 5 would ok on a higher octane fuel, or if I might have needed to do something to get it to run as efficiently as possible. I run it on standard unleaded now, as I guess the owner before me did too.

K

[skinny]

you can run on as high octane as you want without doing anything - but the only benefit you'll get is from teh better detergents in super unleaded.

[MaximumJed]

It's only made a difference to ours since we had the timing mod done, it's been advanced quite far to take advantage of the different fuel and means it runs terribly on 95.

Worth doing the mod though, had the garage do it when it was in for service so it didn't cost much.

[Kinky]

AHA - ok - so the timing does need retarding.

Thanks for that

[skinny]

you can advance the timing giving you more power to make the most of the 99RON if you want to run on that.

you only need to retard if you have tuned your car for 99 and you then want to run it on 95.

Edited by skinny on Tuesday 11th March 22:49

[MX-5 Lazza]

I can't see the point myself. Using super unleaded and advancing the timing is a fairly expensive way to add maybe 5bhp. Better off using standard unleaded, setting the timing to 14BTDC and using the full rev-range more often.
I use super all the time but then I have a supercharger giving me 226bhp and 195lb/ft