FRPP 4.10's installed last month on my GT Auto. I wouldnt buy another Mustang with out them.

 

My overall gas mileage with 3.73:1 gears in my auto is about the same. The engine doesn't have to work as hard when pulling away from a light.

My highway mileage is down a solid 2 mpg. That makes sense, too. (3.73:1 will increase your RPM about 12% over stock.)

You can't get something for nothing. If you do a lot of city driving, then 4.10:1 probably won't hurt your overall very much.

That said, 4.10:1 in an automatic means 20% higher RPM at highway speeds. So, instead of loosing 1-2 mpg, you're going to be dropping about 3-4 mpg on the highway. If you do a lot of long highway drives at a constant speed, then you'll especially notice the difference.

I'm very pleased with the 3.73:1 ratio in the car. I often drive the car 90 miles (round trip) to visit relatives, all highway mileage. 4.10:1 would not have been a good match for me.

 

no the shifting was good. took a few days to get used to 1st being so short. but then in 5th gear going down the highway i was waiting for it to shift again when they were first in. i noticed a increase in city mpgs and a drop in highyway. i think i was averaging 20 city and 24 highway. i only cruiz at 70 or so.

 

Anyone know why Late Model Restoration has FRPP 4.10 gears so cheap? Only $150.....They are NOT Motives!

http://www.latemodelrestoration.com/...1&comp=LRS

And for just $260 you can get the gears and installation kit together!

http://www.latemodelrestoration.com/...1&comp=LRS

 

That is not enough oil for one, and for 150 those are not FRPP gears, hell most places sell the motives for higher. They would have to be used or something

 

i think im ordering that kit thanks man!

 

hmm..http://www.buyfordracing.com/shop/index.php?cPath=3_37 they are 150 bucks here.

 

Says "FRPP" on the ad. I dont see how the could be Motives, thats false advertising. Free shipping too. I was gonna pick up a set at Mustangsunlimited here in Atlanta, but that deal is pretty sweet. Getting them installed next sat for $285. Still on the fence about ratio 3.73, 4.10, 3.73, 4.10,... Seems about 50/50 on the opinions here.

Howarmat, why is the auto tranny geared better for 3.73 as you stated? I don't understand.

 

These are the internal gearing numbers for the trannys. Since the auto and manual transmission have different internal gearing, the rpms and such are different in different gears.

Automatic transmission gearing
1st: 3.22 .1
2nd: 2.29 .1
3rd: 1.55 .1
4th: 1.00 .1
5th: 0.71 .1
Rev: 3.07 .1

Manual Transmission gearing
1st: 3.38 :1
2nd: 2.00 :1
3rd: 1.32 :1
4th: 1.00 :1
5th: 0.675 :1
Rev: 3.38 :1

The final drive gear is calculated by using the tranny ratio times the rear end ratio

So in 5th gear you would have
M: 4.10*.675= 2.76
A: 4.10*.71=2.91
A: 3.73*.71=2.64

Ideally a 3.90 gear set in the auto would equal the 4.10s in a manual but they are NOT a FRPP gear so that is one reason most people don't use them.

Notice other gears besides the final gear too......some of those numbers are much different in the auto than the manual. Its really personal preference but usually you are stepping up from 3.31s in the auto and going up to the 3.73s will give you a nice kick in the pants and the RPMs on the highway aren't terribly high this way.

 

since you have to drive 50 miles a day I really would recommend you not get gears but instead put the money into other mods. A tune, CAI, headers, exhaust, etc.

Unless you enjoy spending the extra money on gas for as long as you have those gears in... and taking a roll of the dice that the install will come out fine.
We've had some bad gear installs on MF. Many come with the whine. All will come with higher rpms.
If you had just a weekend fun car I might say try it... But not for a daily driver, IMO