Loosing more and more MPG!!

[GreyStone]

So....is there a chance they replaced my front differential with the wrong gear? Is that even possible?

anything is possible - but I would hope not,. Do you drive around mostly in 2wd or 4wd?

 

[Jolly Roger]

Both, summer its mostly in 2wd. Winter is in 4wd...

https://www.differentials.com/gm-axle-ratio-identification-codes/

 

[Jolly Roger]

If I recorded myself rolling over my cell phone, would I see the front drive shaft turning faster or slower compared to the rear one if the wrong gear was put into my front diff?

 

[Jolly Roger]

Im sure I can find the paperwork of when they changed the frt dif, I wonder if the part number is listed on the receipt......hold on..

 

[GreyStone]

GT8 Axle Rear (Dup of GT5) 4.10
GU1 Axle Rear 2.41
GU2 Axle Rear 2.73
GU3 Axle Rear 2.93
GU4 Axle Rear 3.08
GU5 Axle Rear 3.23
GU6 Axle Rear 3.42
GU7 Axle Rear 2.77
GU8 Axle Rear 3.90
GU9 Axle Rear 3.91

 

[GreyStone]

Did you change load range when you changed tires? Ranges D and E are exceptionally heavy tires. - compared to P or SL

 

[Jolly Roger]

Did you change load range when you changed tires? Ranges D and E are exceptionally heavy tires. - compared to P or SL

Nope, replaced load range E for E..

 

[Jolly Roger]

 

[GreyStone]

Nope, replaced load range E for E..

Honestly with 4.10 gears fuel mileage is mostly an afterthought. They are powerful gears but are about the lowest you would want on any passenger truck.

 

[GreyStone]

DP