Fuel Question

[V8HSV]

Paul-C said:

V8HSV said:

Optimax for me every time too, Tesco 99 in my experience does not offer more power over optislurp plus I get worse economy with it, don't like BP Ultimate, use Esso 97 ron or Texaco 98 Ron if no slurp around. Been warned about additives too many times, mind you that is what the fuel companies do I suppose. Good point about petrol going off, need to use a garage that has a busy forecourt to ensure fresh supplies.

Just a quick comment........there are additives, which are all a complete rip-off except two brands of injector cleaner and Millers in my experience. I have used, and still use CVL in a number of seriously expensive performance cars, not just Holdens, as learnt it genuinely works with no detremental effect during my racing days. Given the engine rebuild cost on just one example would be circa 100K trust me when I say I would not recommend anything that I have not had (long term) first hand experience of.

I will take your advice Paul & try it out real soon, cheers

Edited by V8HSV on Friday 9th June 08:26

[barking]

A '04 CV8 with Sports Pac, has been run on normal fuel as no mention of using anything other was made after the tune, is now been run on Shell SUL (is that the same as Optimax).How long before the car resets its self for upgraded fuel?

[ringram]

Unless you can scan and read the adaptive spark level you wont know.
Paul might be able to tell you how fast he has tuned the recovery in.
Mines set to 100% all the time and I now run on 98 due to 11:1 compression.

[barking]

Paul can you rember you carried out the tune at Greens mid may. But for anybody else what is the worst case scenerio.

[uk hsv]

Your car like all "Sport Pac" cars can run without problems on "95" but to extract the last few HP it is good to use 97-98 fuel..........

A couple of tanks of good fuel will do the trick as the migration to max spark is resonably agressive....

[barking]

Thanks Paul. Just my luck one tank full then the only Shell garage in the area has been taken over by Total. No BP around so I have a choice of Tesco 99 or Esso. Paul from previous post I think you use something more exotic, if not what do you use?

[uk hsv]

Tesco 99........its cheap and works just fine, also they sell a lot so always get a new fill....

[doleboy]

I use either BP Ultimate or Optimax. I swear though the last few goes of Optimax have been most odd - car seemed slower. I though I was loosing the plot until I read Paul-C's comments.

I may have to go further afield - nearest Shell garage surrounded by fields - guess not many tractors need RON 98.

[AM04ARO]

silly question.

Am I right thinking that it takes a couple of tanks to get the better out of high octane fuel? I have filled up after standard, noticed little difference and gone back. Am I mistaken and should use two to three tanks and then decide?

Waitrose Super is best for convenience - any opinions?

[ringram]

You will only benefit from higher octane if the engine is tuned for it.
MBT will differ for each fuel. Higher octane actually has less engery than lower octane. It depends on how close your chosen fuel gets you to MBT (Min Best Timing or Max Break Torque). If higher octane gets you closer to that point you are better off with it.

Anyway if you want to test pull the PCM relay/fuse out and it will reset to best timing. Then try a tank of each and see what runs best. If you have had an aftermarket tune ask the tuner what they recommend as they may have designed the tune to be optimal with a certain octane.

[HSV FAN]

Very interested in all your comments, thanks. Think ive sorted it now? Can anyone tell me (or ringram) what he does for a job?
your comments were great cheers