Is it a myth that your fuel effeciency suffers as the result of going with 4:10 rear end differentials on your 4 valve? I need several responses and thoughts on this please.
Well theoretically it should. Any time your engine RPM is higher at cruise speed will result in higher fuel consumption. For example, if the car was turning 2000RPM's at 70MPH with the stock gears and you swap those out for 4:10's your RPM's at 70MPH will now be higher. Higher RPM burns more gas.tama said:Is it a myth that your fuel effeciency suffers as the result of going with 4:10 rear end differentials on your 4 valve? I need several responses and thoughts on this please.
Snakestress said:true story, i just went from 3.27 to 4.10 in my 97 cobra. I used to get 20 mpg (i drive all highway). after the gears i got 21.5. seems like my mileage actually improved and i dont know why but im not complaining..
Uncle Meat said:Well explain to me why Ford doesn't install 4:10's at the factory if they are so great for gas mileage? It would raise their overall C.A.F.E. ratings which would be better for the company overall.
U.M.
Cavallo said:FACT:
Gas mileage will go down on the freeway.
City MPG will go up a little.
I agree with UM on this one, Ford knows what the right ratio is for MPG and 4.10 are not it.
The only reason a Vett is getting great MPG is the 6th gear and only 1600 rpm cruise rpm at 60.
THINK ABOUT IT !!!