Fuel Type

[over_the_hill]

Having taken the plunge and bought one, I noticed
(and perhaps should have thought of this earlier)
that there is a sticker by the fuel cap saying
'98 ron only'. Since then I have been checking
local garages (will be collecting the car soon
so still in my old one) and not many seem to
sell super anymore. What is the recommended
substitute, and other than performance would it
hurt to use premium 95 ron at a push if caught out.

[PhillWalden]

There are loads of posts covering the different fuel types. Lots of people will only use Shell Optimax and nothing else.. Personally I find that it does not make any difference to the performance of my car Chim 4.0l It runs quite happily on normal 95 RON

[M@H]

Shell Optimax is 98 RON and the preferred fuel for the car. If you can't get that then get super unleaded, which is 97 RON (used to be 98, hence the sticker). Don't run it on Normal Unleaded though as you can risk it Pinking.. ..if you want to do this, you can get the car "de-tuned" for the purpose.

Cheers
Matt.

[pbrettle]

As Matt says - 95 is fine but 97/98 is preferable. Mine has had the timing adjusted to take 95 without a problem and I have NEVER had any pinking at all. However, you do sacrifice a small amount of power for doing this.

But a decent TVR specialist will be able to sort this out for a small cost. The engine it self should suffer no long term affects for using 95, but if it starts to pink then you could be causing some problems. Try it and see....

P.S. Although its not legal, can you can a TVR on 100 or higher RON fuel? Anyone know?

[GreenV8S]

pbrettle said:

However, you do sacrifice a small amount of power for doing this.

It's true you may sacrifice a small amount of power, but only a tiny amount too small to be felt by the driver. Other things being equal, power drops off fairly quickly as you retard the ignition. But lower octane fuel burns quicker, which means you can light it slightly later and still get virtually the same power. Changing to lower octane fuel and retarding the ignition slightly tend to counteract each other and done right the net result is only a very small power loss.

[snorky]

the higher the RON, the higher the "resistance" to pre-ignition when the fuel is compressed in the cylinder of your engine before the spark plug goes of. Therefore, the higher compression your engine has the higher the RON of the fuel will need to be to stop pinking. I have run my Chim 4.0 on normal 95 RON with zero pinking so far and could tell very little difference when I did run it on 98 for a few weeks. Measuring RON is a very imprecise art ....

[bassfiend]

snorky said:

Measuring RON is a very imprecise art ....

I had no problems, in fact it's easy - 5ft 11 but he did look at me strangely when I asked him to stand still and took out the tape measure.

I suppose he was a little under 5ft 11 so maybe you're right - yeah - maybe it is a little imprecise after all.

Phil

[simpo two]

My Griff 500 lives on unleaded quite happily - though if I did trackdays etc I'd use super.

[ncs]

I prefer to use Optimax in the Griff, but the new BP Ultimate (97) is becoming readily available & I use that if there isnt a Shell garage about.

Works well for me.

Nick

[jessica]

I use optimax as my 1st preference,and second is the new ultima fuel from BP.

Trevor had to have unleaded 95 ron the other day as garage had run out of optimax,and he doesnt like it. he runs without pinking but I can tell the difference.

[shpub]

There is an unleaded FAQ on www.tvrbooks.co.uk