A mate of mine used to own a Chimaera.
I told him how the S needed Optimax/98 RON petrol, and he said that they said the same for TVRs, but that it was a load of twoddle.

What, and how MUCH difference does it really make:
a) to the engine
b) to the drive
( c) to the wallet ) ???


San.

 

You don't NEED it - the MY02 and later is quite capable of running on 95 RON normal unleaded.

Shell also makes great claims for Optimax keeping the engine cleaner and avoiding performance-inhibiting deposits which you can get from other fuel. No idea whether this is just marketing spiel or whether it has any scientific basis, but the feature which Evo did on it last year seemed to show that there was noticeably less build up of crap after several thousand miles of using Optimax compared with normal or super unleaded.

Personally, I find the engine runs smoother and is more responsive with Optimax in the tank. My imagination? Maybe. But since it only tends to cost 4-5p more per litre than normal unleaded, and is frequently cheaper than super unleaded elsewhere, why take the chance on the cheaper stuff? The difference between a tank of 95 RON and a tank of 98.7 RON Optimax is only a couple of quid, even if the tank is absolutely empty.

If you can afford an S in the first place, you really shouldn't be worrying about an extra

 

with the Lurking Lawyer - the extra fuel money is marginal compared to other costs like depreciation. A small price to pay for peace of mind.

I remember the first time I put Optimax into my MX-5, it was like woooah ! Unfortunately, I never felt a difference after that Perhaps the additives helped to get rid of some of the gunk.

 

The price difference is not really the issue, hence the cheeky brackets!
Just don't want to fall for (untruthful, shall we say) marketing ploys, but if the evidence is there, I'm reasonably happy!

(also...'Optimax stop' sounds better than 'super unleaded/premium unleaded stop' )

 

I stuck Sainsbury's SUL in at the weekend and I can't say the car felt any slower but........I did notice some hesitancy in VTEC...I am putting this down to maybe some contaminant in the fuel as it happened only once or twice

I think the Shell is likely to be of more consistent quality so I am more likely to continue using this. I will say though that in my experience ESSO SUL has given me the smoothest performance

For me cost is becoming more of an issue than it used to be but I'd certainly not choose a cheaper fuel simply due to cost

 

I had a lot of trouble with kangarooing when I used Sainsburys SUL (and it was really embarassing, as well as irritating).

The problems disappeared completely after going on the Optimax diet.

On the occasions when I have had to use normal unleaded, I do notice a definite lack of sharpness in the throttle response (which is after all why I bought a sportscar).

Other SULs seem to do a similar job to Optimax, and I noticed recently that Q8 SUL is actually 98 octane also.

 

Euan...I've also used Q8 98 which I stick in if the car is going to be standing a while.....I think it's even better than Optimax but it's pricey

 

He speaks the truth ...

 

I'm not that technical but if you keep changing fuels the cars ECU has to keep re-adjusting itself to the new diet..... if you stick to Optimax (or one brand) the ECU doesn't need to adjust itself as often?

 

I only tried it once, and with a fully laden car, so it was difficult to tell what effect it had - but if it makes the car go better, I must try it again