95 RON

[Michael.McD]

While cleaning round the boot today I noticed a sticker above the petrol cap which says Warning use only 95 ron only! or some such.

I suppose this means the engine managements fuelling and timing etc. has been optimised for 95 ron fuel.

Would anyone here know if this means that my using 98+ Optimax is having a deleterious effect on the engines performance, or longevity, or that it's a waste of money, or what?

Michael M.

[donaldhunter]

No detrimental effect, possibly just a waste of money. But my Tuscan is prone to pinking under load with 95 RON which is cured by using 98 RON. If I remember correctly, my manual recommends using 98 RON for track days.

[cafcfan]

Have been using 95 on a Tuscan S and it seems fine - much to my surprise. But my guess would be that you do lose some power. (The reason for the recommendation to use 98 for track days?) Interestingly by way of comparison my Audi's computer indicates that economy also falls using 95 and that more than balances out the extra cost of the dearer fuel. My recollectioon is that the Audi's handbook admits to about 10% less bhp (or ps as they say in germany) for the lower grade fuel.

[Graham66]

Optimax also has more/better cleaning agents than some fuels, so using Optimax should not do any harm to the engine.

I spoke to John Ravenscroft about a year ago and he said he is not allowed to recommend a fuel, but he uses Optimax and engines they have rebuilt that have been run on Optimax have been cleaner than other engines - that was enough for me! Optimax wherever possible for me now

Graham