13 replies to this topic

[Lordbenny]

When I had an all bells and whistles 400bhp turbo'd Ford Focus I was told only to run it on High Octane fuel, which I did. I presume that my standard N/A is mapped for 95 and that 97/99 will make no difference to anything as my cars management system does not have sufficient self adjustment to optimise it's settings for the higher octane and it's associated benefits. My car's ECU is still set as it left the factory so I am not going to feel any difference if I use it am I?

[Phear]

You will gain a bit after a while, but not much.

[The Batman]

Nope except for the placebo effect

[james12345]

only used high octane in my NA a few times, can't say it makes any difference.

[2.2_na]

I am not going to feel any difference if I use it am I?

Just a lighter wallet.

[ianrm]

There is a benefit from running on 99 Ron. The ECU will adapt after a few tanks to the 99 and give you slightly better BHP and MPG. If you go back to 95 it will un-adapt straight away and then take a few tanks to adapt back up to 99 again.

[ArticMonkey]

I've been using 99 in my SC NA and I would assume this is best seeing as its mapped?

[VIX]

I've been using 99 in my SC NA and I would assume this is best seeing as its mapped?

Courtenay warned me not to use less than 97 in my SC.

[Tony H]

Is premium better for the engine in any way?

[Rosssco]

Theres a big sticker on the inside of the door shut saying 97-99 ron only, it's a Courtney remapped car... You will typically feel no difference in using higher octane on a standard car, but higher octane fuel usually contain additives that can help prevent build up of deposits in the fuel system, and supposedly in the combustion chamber, but again, would you notice any difference?! A bit like those little bottles you buy from halfrauds etc.

[slindborg]

There is a benefit from running on 99 Ron. The ECU will adapt after a few tanks to the 99 and give you slightly better BHP and MPG. If you go back to 95 it will un-adapt straight away and then take a few tanks to adapt back up to 99 again.

"slightly" reading as very very very marginal

for ANY engine, unless its been calibrated to take advantage of higher ron (and less energetic ) fuel then dont bother (even goes for those cheating with FI )
The OEM Z22 cal was based on the US where they have some dire low 90's stuff and the 'premium' is 95 i very much doubt there would have been much tweak for europes calibration bar the NEDC stuff.

[Tony H]

Sounds like I have been wasting money!

[14500rpm]

There is a benefit from running on 99 Ron. The ECU will adapt after a few tanks to the 99 and give you slightly better BHP and MPG. If you go back to 95 it will un-adapt straight away and then take a few tanks to adapt back up to 99 again.

"slightly" reading as very very very marginal

for ANY engine, unless its been calibrated to take advantage of higher ron (and less energetic ) fuel then dont bother (even goes for those cheating with FI )
The OEM Z22 cal was based on the US where they have some dire low 90's stuff and the 'premium' is 95 i very much doubt there would have been much tweak for europes calibration bar the NEDC stuff.

IIRC they use a different rating system for fuel there so a direct comparison is misleading. Our 98 (RON) is approximately equivalent to about 90 (MON) there.

[J4EY D]

Sounds like I have been wasting money!