Quick "Which Petrol" Survey

[ghosty o''shark]

When I bought my Tuscan I was advised that normal unleaded was the best fuel unless I go on a track day. Since then I've used normal unleaded but most threads on this site suggest Optimax or super unleaded for its higher RON number. see www.pistonheads.com/gassing/topic.asp?t=14183&f=13&h=0&hw=optimax

So was the recommendation to save me money? Should I use Super Unleaded or Optimax or will normal do?

[luca brazzi]

I've always used Optimax...no point penny pinching on fuel...IMO

[Lagoo]

Optimax all the time here too!!!

[M@H]

not seen a difference with optimax yet... thinking about going back to unleaded....
Cheers
Matt.

[plotloss]

Opti!

Unleaded in emergencies though.

Matt.

[N17 TVR]

Optimax, both for the car and personal use......

My breath has never been so fresh, and as an underarm deodorant and eau de cologne it has proved a sure fire winner with the ladies.

Do I win this weeks star prize ?

[LOVEMYTVR]

Optimax for me every time - I think the car runs smoother and its supposed to help to keep the engine clean - good enough for me!!

Neal
W9 TVR

[ajvmoore]

At elvington last summer - super in the morning and I maxed at 176mph, couldn't find any when I filled up at lunch so on unleaded in the pm - maxed at 165mph. QED. Now use optimax when I can.

[mcspreader]

changing to normal from optimax will give big drop until the computer learns about the new fuel which takes time. then drop is smaller

[scruff400]

When 'encouraging' the throttle running 95RON the engine pinks.
It's creamy smooth with 98RON.

Shell support vivisection.

[sixspeed]

Ran unleaded for about 2 tankfuls when I first got the car, before realising it was crap. Now fill with eitherOptimax, but prefer BP Super if I can find it.

When Optimax was released, a magazine ran an article testing it against other Super Unleaded petrols (which is really what Optimax is) on some high-boost turbo cars (modified Scoobies, Cosworths etc). The cars running Optimax all suffered detonation at lower-boost levels than when running BP Super Unleaded.

-andy-

[dannylt]

Morning vs. afternoon giving different speeds - you CAN'T blame this only on the petrol. Could be weather conditions - colder morning would definitely mean more bhp. Or maybe different speed on to the straight?

Another myth - the engine DOES NOT learn to change the ignition advance when you put a higher octane fuel in. It does not have the knock sensors, and TVR mapped all speed 6 engines for unleaded. Super unleaded is still a good idea for track days though, since detonation is more likely with a bloody hot engine being thrashed.

Optimax could well clean the engine better... who knows.

danny

[sixspeed]

I noticed considerable pinking on my 'S', which is why I started filling with Super/Optimax. This was just "normal" road driving

So I fill with Super now, but still the car pinks sometimes when it's been sitting in traffic for a long time and the oil and water temps are up to 90-odd. Also near the end of sessions at trackdays, I get pinking in 4th and 5th (high loads of on the engine). Again the oil temps are reaching the 90s... but this is for another thread me thinks.


-andy-