95 or 98ron ???

[neil_jdmr]

Getting my pfc mapped by pip in a fortnight but was wondering how many of you get your cars mapped to 95ron and why?.
 
Is it just for mpg reasons or is it safer as far as knock levels go
 
The reason i ask is iam happy having my car mapped to 98ron as i only ever put optimax/vpower in it anyway.

[logicalChimp]

hmmm - mapping for 95 would make it safer in the event you get stranded and end up being forced to use Esso cr*p or similar...

*should think it would massively affect your mileage or performance (although there probably is some impact, it may be slight - but as my car is still running stock Jap ecu, i don\'t know for sure either way - im just here to kill time in the office... )

[neil_jdmr]

Mm I suppose, but if i was caught in that situation i would just put a tenner in and stay off boost until i got to the next vpower station.
 
 
At the moment im the same as you and am running the jap stock ecu which is mapped for 100ron and i (dont think) ive had any probs using 98ron even when giving it the beans.

[gsb876]

If you got caught short you can use usual unleaded but just take it easy thats all.

[m1tch]

Only run your RX on either 99 Ron tesco stuff or V power high octane, its a high performance engine and needs decent fuel, some jap cars mapped for higher fuel and have been fueled with 95 ron have had issues and the engine has failed, high octane fuel is only a few quid more per tank so its worth it.

[Ricco_04]

You can run on normal as long as you dont go mad, ie dont hit max boost, rev limiter etc.  Depends on the map, some are richer and can get away with it.  A guy I know drives his car to the strip on 95 and its mapped on race fuel - cant give a better arguement than that!

Yes mapping on 95 gives you all the choice in the world plus the option to put the \'better\' stuff as a margin.

I just had my car remapped, went from Vpower @ 99ron to whatever @ 95ron.  Im running the same boost, no difference on fuel consumption and managed 2bhp more but I am on an engine with better compression! :Thumbs-up so power difference I cant give a fair comparison but I wouldnt have thought it would not be all that much?