Thread: MPG
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Old 08-11-2006, 05:32 AM
Michael1 Michael1 is offline
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Default Re: MPG

Quote:
Originally Posted by ChevyHighPerformance
The H3 has two spark timing tables - high octane and low octane. The data in 2D tables are arranged by RPM and cylinder airmass. The PCM starts on the high octane table and if knock is detected reduces the timing until knock is gone. The working timing table usually falls in between the high octane and low octane tables. However, the H3 is the only vehicle that I have seen that primarily stays on the high octane table which means there is no room for timing advance to take advange of higher octane gas. This is why you don't feel a power/MPG improvement with the higher octane gas.

Are they using a wideband knock sensor on the I5?

Michael
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