Gears

Stangman04 · **Gears**

I have a '04 GT with and an auto. I am looking for specs on adding 4:10 gears. I would like to know what changes in RPM, MPG, HP/Torq, etc... I am looking at.

**SpectorV** · **Re: Gears**

the rpms increase by 250 if i remember correctly for 3.73s so a bit more for 4.10s

I lost 2mpg~ hwy and gained like 1 city with 3.73s

HP/TQ wont really increase it will just alter its multiplication via the rear wheels~

whipster24 · **Re: Gears**

there are calculators all over the internet. You won't lose that many mpg with gears on the highway unless you rev it really high. And you will likely gain mpg in town.

**SpectorV** · **Re: Gears**

you will notice the gas difference on the highway at more than 55mph.

Stangman04 · **Re: Gears**

Thanks to all. As far as the HP/TQ, I wanted to know the WHP/WTQ. I found the caculators. I'll post my specs in the next month or so.

**bbunt302** · **Re: Gears**

The rwhp and rwtq will also remain the same. Gears don't change the amount of power the car is making. They change the rate at which that power is applied to the ground. The ratio of the gears is simply the number of times the rear axle(s) will be turned based on how many times the driveshaft is turned.

So at any RPM, you won't actually be making any more power. But for any given speed in a given gear, a move from stock gears to a lower ratio (higher numerically) will cause an increase in RPM. Thus effictively putting you in your power band more quickly.

This is why some people are afraid that they will "lose top end" because of gears. They will indeed lose some of their "theoretical" top end. But what they don't understand is that this theoretical top end really doesn't matter in most applications. Most cars that any of us deal with don't top out due to lack of gear, but rather due to lack of power to overcome wind resistance. That's why gears in some many instances will actually increase a car's top speed. When the car is doing 140 mph, the engine will now be at a higher rpm (thus hopefully making more power).

Anyway, hope some of this made sense.

neatofrito1618 · **Re: Gears**

Id go with 4.30's on a GT auto.

whipster24 · **Re: Gears**

Heck, my car should do 150 still with the gears. I went 3000 rpm @ 75 mph. I'm pretty sure I could hit the rev limiter in 5th if I wanted to


Quote: Originally Posted by bbunt302 This is why some people are afraid that they will "lose top end" because of gears. They will indeed lose some of their "theoretical" top end. But what they don't understand is that this theoretical top end really doesn't matter in most applications. Most cars that any of us deal with don't top out due to lack of gear, but rather due to lack of power to overcome wind resistance. That's why gears in some many instances will actually increase a car's top speed. When the car is doing 140 mph, the engine will now be at a higher rpm (thus hopefully making more power). Anyway, hope some of this made sense.

tealstangman · **Re: Gears**

i got 4.10's and if i did it again id go with 4.30's

Danger Dude · **Re: Gears**


Quote: Originally Posted by tealstangman i got 4.10's and if i did it again id go with 4.30's

Not if you drive the interstate much. Unless you are a avid track hound getting 4.30s is a waste of fuel. Since Gas is really never going to get a lot cheaper and is only going to keep going higher do you really want to lose 4 mpg or more.