setUout

i put in a few gallons over this past weekend. and i must say i really liked the outcome. you could feel a bit of diff. anyone else try this yet?

Chappy

Last fall, I put 10 gallons of 100 unleaded in an empty tank @ $4.99 per gallon. The next day I was at the drags and still could not best my previous runs on good-ol Amoco 93.

$50 bucks down to drain. Never again to a stock engine....to get the benefits, I need ECU tuning or boost

awiner

Using high octane gas is something that I have always wondered about. Everyone in the tuning industry I talk to however has told me the same thing. They say that unless your ECU's fuel map is updated and programmed for the increased octane there will not be a difference.

AaronC

I have run unleaded 100 before. It made a difference, but I was not at the track so I cannot quote times. I think 100 is overkill. The ECU will adjust timing to accomodate the higher octane, to a point. I remember a guy here on the site got 300+WHP on a completly stock C32 using 98 octance. That is 10-20 more then normal. When I go to the track in March I am gonna mix my gas to 98 octance too. In case you dont know how to figure it, here is the formula:
(Gallons of 93 * 93) + (Gallons of 100 * 100) / Total Gallons = Combined octane of gas

Examples:
(2 * 93) + (5 * 100) / 7 = 98 Octane
(3 * 93) + (4 * 100) / 7 = 97 Octane
(4 * 93) + (3 * 100) / 7 = 96 Octane
(2 * 93) + (3 * 100) / 5 = 97.2 Octane
(1 * 93) + (2 * 100) / 3 = 97.6 Octane

BlackC230Coupe

I put like 5 or 6 gallons of 100 octane in my C55 at the track after i had about 1/4 tank of my regular 93 octane, i must say, i honestly didn't feel a difference at all. Also, my best times i got at the track was when i used just 93 octane. The 100 didn't affect my times. All though that was when i was on the stock wheels with no traction, so it would be better for me to try when i am on my better tires or drag radials.

ronnie0738

damn, you guys are complaining about 93??? we here in cali are stuck with 91 and I mix in 100 just to get 93-94!

setUout

thats what im doing. im also in cali. from time to time i put in 101 like 5 gallons to 5 gallons of my 91. i wish we had 93 here.