4.10 to 3.08
 

just wondering how much difference would i notice from 4.10s to 3.08s in mpg on a 3.0 also would it become really slow .. my dad a ford service manager like 27 years experience said it would help the mpg alot and a guy got the gears from a mustang brand new too that he would give to me but im nervous about it hurting everything else with mpg gain any advice?

idk what it would do in terms of hurting things and of course this isnt a 3.08 but my 95 ranger 4x4 with a 3.27 in the rear didnt do too bad. i just ran stock size tires on it. got somewhere like 23 or 24 mpg's on the highway with the 4.0 V6, so i'm sure it'll help with gas big time. just down know if it'll hurt things

The 3.0 get better gas mileage in higher rpms. I think 4.10's are better for it. What will increase mileage is accelerating slower and driving slower in general.

My grandpa get 29 mpg city/highway with his 87 Grand Marquis (5.0) by driving like, well, an old man. Thats how you save the MPG.

he's right, the 3.0L doesn't do that great in lower RPM's. Depending on the tire size I'd say 3.55's to 3.73's would probably fit you better.

yea smaller displacement engines do better at higher rpm. The engine does not have to work as hard to pull itself around since its in its powerband more often.

So the free 3.08s would be a bad idea thats kinda what i though too was thinkin like 373 but my dads friend was like hey i got a new pair of 3.08s and i was like ok haha but i most likely wont change from 4.10s unless its to maybe 3.73

im running 3.73s with 26 inch tires. puts me at a 4.12 gear ratio. i get 18 on average city/highway. and i have some get up and go too.

yea you'd lose probably 5-8 MPG at least by dropping to a 3.08.