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Old February 15th, 2008, 09:01
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birchlakeXJ birchlakeXJ is offline
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Join Date: Jan 2008
Location: Melrose, MN
Posts: 2,779
Re: 0331 head swap, mpg change?

I would calculate your mileage pump-to-pump with a calculator and a notebook for a few weeks. See if there is any difference. Concentrate on just the MPG calculation, not the amount of miles. MPG tells the whole story.

Also remember that winter brings lower gas mileage with colder temps, longer closed loop, reformulated oxygenated fuels, etc. I highly doubt that the head is responsible for a significant mileage decrease.

You could try replacing your "upstream" oxygen sensor if it's old as they become sluggish and can't optimize the fuel/air ratio as well over time. Simple tuneup stuff too can help optimize gas mileage. Oh and easy on the right foot can't hurt right??
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