4.10's & Gas Mileage
 

For all you 4.10 guys out there: I'm wondering what kind of gas mileage you all are getting? My car is basically stock (flows & FIPK), so I would like to get an idea for a mostly stock automatic 2000 GT. One more question: why are 4.10's better for an automatic than a stick?

You will lose 4-5mpg :eek: with 4.10s. Sitting in the fast lane on the freeway you will be cruising at 2900-3100. You will love the around town getup, but when you hit it from a roll on the freeway, you wont have much to work with. If I could do it over, I wouldnt put the gears in my GT....Instead, I'd save for a blower. Please, if you can afford it, heed my warning!

You would go blower before gears?? Hmmm...I dunno. You're the expert, but I would recommend for lower budgets to get the gears. Stoplight, don't you still need gears even after the blower?

I went from 20 MPG to 19MPG in the city and 27.5 MPG to 27 MPG on the freeway with 4.10's. It's not nearly that much of a difference.

Bill

Bill, you have a stick, toppchef and I have autos. In the cobra, with the 3.73's, I didnt notice any loss in MPG...in the GT, I did lose 4mpg. I dont know what else to say, that's the case.

Titan: With an auto, if you go with gears, and then get forced induction, you will run into problems with your computer shifting at WOT. With a stick, if you're making crazy power, and you put steeper gears in, you're gonna have that much more trouble getting off the line, cause you'll sit there spinning like crazy. But you're right, if you're on a budget, the gears are a great mod.

You got a light foot there bill. I'm only getting 17 or so and I'm running 2:73s. But I'm pretty heavy on the gas just about all the time.:D

I actually got better mileage in my 91 LX 5.0 5spd when I changed from 2:73's to 3:73's. Thats because I never really did any highway driving, and the gears let me get into 5th when driving around at 40-45mph. Where as before 5th gear was only good for 60+, a speed I was hardly ever at.
But for an auto, I don't think you should lose anymore then 1-2mpg around town, but definately a lot more if you do highway driving.