OPTIMAX - Why ?

[John Mac]

Several threads I have followed seem to plug for using Optimax fuel - why is this ?
For me to use it means a 20 mile round trip - is it worth it?
At present I'm running on Unleaded 95 Ron and it seems OK.
Thanks in advance

[spnracing]

No its not worth it.

If your S has been tuned (ignition retarted slightly) to run on 95 then it will do so fine and you will NEVER notice the performance increase by using 97 or even Optimax (98.4).

If you took the S to a rolling road with a tank of Optimax in it, then got the ignition advanced as far as possible before it started to pink, you might get 3 or 4 more BHP. Again I'd seriously doubt if you'd notice that on the road either - it might be worth a few tenths/lap on a track day. And you would always have to use Optimax from then on.

For the difference in cost (and the long drive) I wouldn't bother.

[Roop]

I use Optimax and the difference is noticeable. Not in outright power, but the fact that the car most definitely pulls a lot cleaner and a lot harder from lower revs than when running on 95 octane stuff. I say run a couple of tanks through and see what you think. Don't know if I'd drive such a long way to get it though.

[johno]

quote:
No its not worth it.

If your S has been tuned (ignition retarted slightly) to run on 95 then it will do so fine and you will NEVER notice the performance increase by using 97 or even Optimax (98.4).

If you took the S to a rolling road with a tank of Optimax in it, then got the ignition advanced as far as possible before it started to pink, you might get 3 or 4 more BHP. Again I'd seriously doubt if you'd notice that on the road either - it might be worth a few tenths/lap on a track day. And you would always have to use Optimax from then on.

For the difference in cost (and the long drive) I wouldn't bother.

Disagree.

The performance of the engine is not the only reason I use Optimax.

I have no doubt that my engine runs better with Optimax than standard or Super. Call it a mental thing whatever but I only use Optimax now.

I use my car everyday, and on track and know its every bump and hiccup and it runs better.

The other reason I use Optimax is that after tests carried out by EVO they showed that it does keep the internals of the engine cleaner from carbon build up. This was on much newer machinery whose engines tend to to develop less fouling than on a 20yr old design such as the 2.9.

Therefor I use Optimax, and will continue to do so in prefernce to standard.

Only other point I would make is ..... why is Tesco's and Sainsbury's petrol so cheap. Because they buy it cheap. Because it's crap !!

[John Mac]

An interesting few comments - If according to the "Bible" the 2.9 engine can run on leaded or unleaded petrol then presumably the EMU takes care of the tricky bits in sorting out ignition etc. Earlier threads have talked about ignition timings of 8 and 12 degree BTDC, the "Bible" says 12 for both fuels, does it therefore REALLY matter what fuel is used for everyday running, I acknowledge that some fuels claim to burn cleaner but does it really and do we keep our cars long enough to worry?
The EMU must be clever enough to read mixed fuels because I've filled with both fuels and I'm still running OK. Perhaps I will run low in the tank and take the 20 mile trip and fill with OPTIMAX to see if I notice any improvement.
Don't agree with Johno's comment on Tesco and Sainsbury, they don't make the fuel they only sell it. There are only a small number of petrol refiners and it all starts out from the same place (generally speaking) I've toured all over Europe and bought petrol that you have never heard of and the car (cars) have all performed without any noticable difference. I'm quite happy with Tesco and Sainsbury - anyway Sainsbury is BP petrol !!!

[tvrmark]

quote:
This was on much newer machinery whose engines tend to to develop less fouling than on a 20yr old design such as the 2.9.

It's nearer 30years

Mark

[shpub]

Yes the bible does say 12 but that is the dizzy setting. The ECU setting does the required timing changes without having to touch the dizzy. So if the car is set for U/L your will probably find little or no difference running Super. Except when you look at the credit card bill....

Steve

[S2 Giles]

I'm not convinced by your Sainsburys = BP !!!!

I stear well clear...used to have a car running leaded which when supplies dried up i thought of LRP except everyone told me to stear clear of supermarkets, they buy as cheap as possible from varied sources and therefore there is no standard Ron level for their fuels......

I also run a type-R that should run 98 Ron and feels weak with 95 Ron in it, feels worse with supermarket stuff.....could be in my mind but its my opinion

Optimax is the best for the Type-R although i use standard 95 ron in the S
cheers

[john mac]

Certainly where I live Sainsburys are BP- their new NECTAR card shows BP as well and the forecourt logo is BP.
Safeway is also BP, logo, pumps etc all showing BP signs.
All pumps have to by law show the correct RON number they dispense, I dont think you will ever go to a garage forecourt and not see this.
Perhaps in the middle of Dartmoor you may still find a hand operated pump not displaying anything, find one and I will eat my petrol coupons !!!
Cheers

[john mac]

I can remember my old Dad telling me whenever you want to sell your car always clean it and put in 5 Star as it will go better.
Mind you - he also told me when braking lights came in to disconnect them as it would save wearing down the battery !!! he was a good Scotsman !!