facacc

I did some searching and then I got tired and lazy and then decided to post. I am just wondering what kind of gas mileage I should expect or "lose" when I go from my 3.31s to the 3.73 rear end? I am not sure if it matters but I am getting about 19 in town when I am keeping my foot off of the gas. But I feel thats good for a v8. I had a f150 and only got 12mpg I dont want to install these gears and be there again.

wingless

Here is a reply.

matt8998nm

I get 20 miles to the gallon in town with my 3.73s

wilkinda

I get 20.3 in town and I get 24.5 to 25 on the highway on average.

I used to get 27 with my '05 with standard GT gearing. My fun factor is higher so to me it's worth the 3.73 gears

GrayGhost01GT

3:73 FTW Defiantly!!!

SirKnightTG

How do the 3.73s feel compared to 3.31? I always hear about 3.31 vs 4.10 but never about 3.73.

facacc

thanks. I was told that 4.10s feel great but are not that streetable. SO that is why I chose 3.73s. any recomendation on oil? and anything else I will need to get for installation. I want to have everything ready for the guys to do the install. I bought the ford racing gears and the install kit.

Gene K

On the 4.6L 3V: 3.73 is the gear for real street tires in my opinion. 4.10 wont gain anything without stickies. (Just my opinion).

3.73 might cost 2-3 mpg highway and run the same to 1 mpg better in the city. If you dont already have one you will need a Handheld Tuner or some other way to reflash the PCM for the gears.

I like the factory Motorcraft Synthetic Lube that comes in the diff along with the factory Motorcraft Friction Modifier for the Limited Slip. I always start with only half the recommended amount of additive and only add more if it chatters going around corners. The LSD bites a little harder with less modifier.

cidsamuth

I had 3.31 and upgraded to 4.10. I love them. You run out of 1st gear quickly, but it feels oh-so-good.

If I had 3.73, that would be find and I wouldn't upgrade. But, if I was upgrading anyway from a 3.31, 4.10 is the way to go.

ShadowLands

3.73 with an auto is a good choice. Lots of fun, very responsive, and still great on mileage. I manage 20 mpg in town and 25 on the highway with my automatic...even with the 3000 rpm converter. Once it locks, no problem.