Optimax vs. Ultimate

[Dippy]

so Dippy,

you saying i will not suffer any problems, if i get the car remapped (AmD RR) while running millers ?
ie if i decide to stop using millers in the future?

Yes that's what I'm saying.

What I don't actually know is how far the ECU can actually advance the timing to take advantage of the octane level used. I know that the OEM setting will work with 98 RON because that's standard in Germany, but clearly there are limits to the range of octane that the ECU can cope with. Mitch from Revo explained that the Bosch ECU does indeed have a finite window, but that this can be set to start anywhere, and therefore a tuner can advance it. Although I don't know where AmD set their's too, I have no doubt that they are aware that their customers use Optimax with Millers, so I'm sure they set it to be able to advance to at least 100 RON.

Again, I don't fully know the details about APR & Revo's fuel-specific maps, but I can hazard a guess: Either it is because the window is so small that it can't cope with the entire range of fuels (but I really doubt this), or it is a more optimised map for the fuel: Advancing timing to near the knock point is only one aspect of ECU engine control. I am sure there are others. So by producing a selection of maps suitable for different fuels, you will always be optimised.

I myself am not really interested. I usually only use Optimax + Millers or another brand 97 RON + Millers. If I am forced to use 95 RON then I will simply expect lower performance until I can get back to the good stuff.

[Paul-RS]

cheers! [img]images/graemlins/thumb.gif[/img]

[s8n]

Found some info on performanceforums.com..

Ultimate

50 ppm max Sulphar
1 % Max Benzene

Optimax

500 ppm max Sulphar
5 % Max Benzene


As you can see, alot more sulphar and benzene in optimax!

[peterb]

As you can see, alot more sulphar and benzene in optimax!

... and is that good?

Probably good for performance, bad for polution?

[s8n]

Well, its performance properties if any could be debateable.

However, benzene is extremly hazardous..

Here is a bit from http://www.osha.gov/SLTC/benzene/

Benzene is an aromatic hydrocarbon that is produced by the burning of natural products. It is a component of products derived from coal and petroleum and is found in gasoline and other fuels. Benzene is used in the manufacture of plastics, detergents, pesticides, and other chemicals. Research has shown benzene to be a carcinogen (cancer causing). With exposures from less than five years to more than 30 years, individuals have developed, and died from, leukemia. Long-term exposure may affect bone marrow and blood production. Short-term exposure to high levels of benzene can cause drowsiness, dizziness, unconsciousness, and death. The following commonly asked questions link to resources that provide information about benzene.

Sulphur is just as bad..

http://www.hse.gov.uk/pubns/chan34.htm#2

Both bad gases, and both present in petrol.. We are doing ourselves and the environment a favour by using a fuel that isn't as harmful to the atomosphere..

Also BP was found to show 98.8RON on average

[wazza]

Also BP was found to show 98.8RON on average

In Australia?

[s8n]

Im unsure where the studies were performed..

[Joules]

My thoughts on the performance benefits for Optimax were validated mostly after running heavily modded Subaru's. My last a Steve Simpson tuned STiV. There was no doubt that Optimax reduced detonation WRT all other fuels I tried. I could see the difference when hooked into the laptop or with the knock sensor I had permanently fitted.

My choice Optimax...