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Discussion Starter · #1 ·
Over the last 5 months my mpg’s have dropped. I’ve lost about 2.5 mpg.
Recently did new thermostats, fuel filters, air filter, pitman, idler, alignment and they haven’t came back any. Last I checked codes I didn’t have any. What else should I check?
 

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Are you running fuel additives?

Have you changed fuel sources?

Do you get fuel from a discounter?


Changed tires? Lift or level change?
 

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Discussion Starter · #3 ·
Been leveled with roughly the same size tires, run opti summer and the same gas station the whole time. I thought the new thermostats would help now that I’m running at temp.
 

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Been leveled with roughly the same size tires, run opti summer and the same gas station the whole time. I thought the new thermostats would help now that I’m running at temp.
I see your in Idaho, are you guys running winter diesel already? MPG tends to drop on winter diesel since it has a lower energy density than summer diesel, thus you must burn more for the same power. May not explain the 5 month trend but it might explain any recent drops. Otherwise there are so many factors that impact mileage it would be nearly impossible to cover them all.
 

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Discussion Starter · #5 ·
Checked my balance rates, all were within 1% -1 to 1. Ran opti lube injector cleaner through also. Cleaned the maf. My last tank came out at 14.4 mpg running on flat ground with no load.
 
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