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Old 04-18-2014, 10:07 AM   #3 (permalink)
Miller88
Master EcoModder
 
Join Date: Jul 2008
Location: NY state
Posts: 501

XJ Cherokee - '00 Jeep Cherokee Sport
90 day: 12.96 mpg (US)

FoFO - '11 Ford Focus SE
90 day: 36.78 mpg (US)
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Quote:
Originally Posted by Daox View Post
Congrats on the better mileage. Do you think temperature had something to do with it too? It does seem like a huge gain for what was done.
The fan clutch was responsible for 3-4 of it. It's pretty routine to take a 3 or 4 MPG hit when switching to the grand cherokee ZJ fan clutch.

I think it was a compounded issue. The fan clutch moved such a massive amount of air that the coolant never came all the way up to temperature (causing it to go open loop quite a bit).

The temperatures had a bit to do with it. I Think running a 5w-40 oil didn't help. At MOST temperatures, it's significantly thicker than a conventional 10w-30.
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