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Re: Higher MPG's on lower octane gas... Posted by Ari [Email] (#2847) [Profile/Gallery] (more from Ari) on Tue, 18 May 2004 13:43:53 In Reply to: Higher MPG's on lower octane gas..., SR, Sat, 15 May 2004 22:50:01 Members do not see ads below this line. - Help Keep This Site Online - Signup |
A few things-
To prevent knock, the engine control modifies engine timing and limits maximum boost. On the newer cars, this is pretty sophisticated and non-intrusive.
By retarding the timing, knock is prevented. You also get a slight improvement in gas mileage. Yes, there is a performance hit, but it's slight.
Second, max boost will be reduced. Again, this isn't the big "drop to base boost" of old, but a very subtle change. Less boost means less fuel. Less fuel is higher mileage.
Lastly, I put a LOT of stock in the 'lighter foot' theory. A few MPG improvement is very easy to see with minor modifications to how you drive. Most of the MPG improvement of aftermarket mileage improvers is due to folks paying more attention to how they drive, which increases mileage. Not the super-vortex-magnoflux-proton duplicator they stuck in the intake.
Without some pretty sophisticated test equipment, you can take a minor performance hit and never know it.
posted by 192.249....
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