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- Location
- Wauchula, FL
Down to the wire, as I’ve started this project of installing Eco Hubs, replacing front axle housing seals, and pinion seals. My plan is / was / I’m not sure to remove my 3.07 gears and put the original 3.90 gears back in.
I’m second guessing my decision, based on a good friend driving a 2007 M1078 with 3.90 gears and eco hubs weighing in at 26,500lbs, converted into an expedition vehicle. He just finished a 10-12 thousand mile trip out west and back. The best mileage he got was 8 mpg on just one of his many fill ups.
Chris another fellow member here on I believe a 2003 FMTV 6x6 converted into an expedition vehicle running eco hubs but with 3.07 gears and weighing about the same. He has reported getting up to 9 mpg.
My top speed has been 60 mph on the interstate roads over the last 24,000 miles but typically on the smaller side roads averaging 55 mph always getting 6.5 mpg.
Looking at the chart from another post it looks like with eco hubs and 3.90 gears, cruising at 60 mph it would be running in 6th gear just under 1600 rpm’s.
With eco hubs and 3.07 gears, cruising at 60 mph would be 5th gear at 1600 rpm’s.
Just talking fuel mileage what would be better?
Pros and Cons?
I’m second guessing my decision, based on a good friend driving a 2007 M1078 with 3.90 gears and eco hubs weighing in at 26,500lbs, converted into an expedition vehicle. He just finished a 10-12 thousand mile trip out west and back. The best mileage he got was 8 mpg on just one of his many fill ups.
Chris another fellow member here on I believe a 2003 FMTV 6x6 converted into an expedition vehicle running eco hubs but with 3.07 gears and weighing about the same. He has reported getting up to 9 mpg.
My top speed has been 60 mph on the interstate roads over the last 24,000 miles but typically on the smaller side roads averaging 55 mph always getting 6.5 mpg.
Looking at the chart from another post it looks like with eco hubs and 3.90 gears, cruising at 60 mph it would be running in 6th gear just under 1600 rpm’s.
With eco hubs and 3.07 gears, cruising at 60 mph would be 5th gear at 1600 rpm’s.
Just talking fuel mileage what would be better?
Pros and Cons?