TexaStang

I do a ton of highway driving. But, I hear that the 4.10 gears really improve the feel of the car ( manual GT ) -- Would gas mileage be affected adversely by the new gearings, or, would there be any other adverse affects?

Martin123

If you have a manual gt you will love the feel of the 4.10's. As far as gas milage let's see:

More highway or no highway + 4.10's = more gas

4.10's + Adverse affects = Wear your seatbelt!

TexaStang

With a C&L CAI, UDP's, Xcal2 and the 4.10's, will it be a huge drop in gas mileage? We talking 10 mpg highway, 15? I don't think I can handle that. My 73 Z28 got 8mpg, just couldn't take the gas price even with it being driven rarely. You seem to have the same mods roughly for what Im shooting for, if you could get me your milage, that'd be awsome.

gregsdart

The worst i could emagine would be the differance in rpms you have to turn. If you go from 2000 to 2300 at cruise, i would bet you will only go from 23 down to 20?
If you have the mileage computor in the info part, then try it in overdrive, go back over the same stretch of road the same time, and in the same direction, and reset the computor at speed each time, and drive at least five miles at the same speed with the cruise control on. That is about as accurate as you will ever get, for the differance in rpms. The 4th gear rpms will be a bit higher than the 4.10 gears and 5th, so you shouldn't lose as much as it will show in the test.

Martin123

I only really use the car on the weekends so for that reason I really don't pay to much attention on gas milage. I will try to get some results. Although, I will tell you that on the highway at 80mph the rpm's are running at 3K so I hope that kind of gives you an idea of the difference in gas milage.

ScreamingYellow

Good grief 4.10's! That is what came stock in my S2K and it had a redline of 9k rpms. I went from 4.10's to 4.57's and my gas mileage dropped from 26 to 22. I think it is safe to say your gas mileage will decrease by 25%.

OICW

With 1 lb-ft of torque at 2,000,000 rpms, I'd get 40.10s if I were you

ScreamingYellow

That's funny. I like that.

There is no doubt that gears are the best mod for the money. I just couldn't imagine having 4.1's on my Mustang. I might consider something like 3.83's. I guess though you already have to make a shift to 4th with stock gearing in the 1/4, so might as well get the most out of it.

gregsdart

On the way home tonight i put the GT in fourth and reset the mileage meter, which would be like going from a 3.55 to a 5.25 gear, quite a change! The revs are up 50%, mileage down from 25/26 to 19/20, and that was over about a two mile test. The 4.10 ratio isn't near as drastic a change, so my guestimate would be your average would drop about 2 or 3 mpg max.

bahbahblacksheep

aside from your gas mileage going down (probably into the mid teens), go and purchase a frequent buyers card at your local tire shop. THey will love you

and the guys at the local brake shop are gonna love ya too! [8D]