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911st 911st is offline
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Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
I suspect the best opportunity for improvement is not on the fuel side!

However, a good working lambda system with the AFR's / CO adjusted to a working range that the lambda can adjust around should keep the AFR's near 14.7 at cruse which would be a good place to start in search of better MPG.

To improve on this look to the ignition for the best gain in MPG!

Most US 911's do not have anywhere enough timing advance at cruse. Usually it is something like 25 deg total advance by about 2500 to 3000rpm. In many cases we are not even going to see our total advance on the freeway at legal cruse speed to run efficiently.

Get total advance to around 33 deg at lite cruse and there will be a measurable improvement. The motor should also run cooler.

A low restriction exhaust for less pumping loss and stock light weight wheels with the right tires for lower rolling resistance can also help.

Last edited by 911st; 09-18-2010 at 10:52 AM.. Reason: spelling
Old 09-18-2010, 07:29 AM
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