gears

[akatoad]

I found a place to buy gears for my ram cheap but they dont come with new reluctor ring is there any way to adjust the speedo for gears?

[mikel]

What vehicle?

[Mike_Levy]

Ram

[mikel]

Can do for an 04-09 Ram...

[akatoad]

yes it is an 04 ram. so do i have to get a custom tune or what? cause i don't remember seeing anything about adjusting for gears when i installed the programmer. thanks for the quick reply.

[akatoad]

also i am running the stock 3.92 gears now. does anyone know how much my gas mileage will change if i go to a 4.56 gear. someone told me i could loose as much as 6 or 7 mpg that seems kind of drastic to me and was just wandering if anyone else had already changed gears and could tell me how much it will change.

[KJ2132]

What tire size are you going to? Or are you not changing

[Quick]

Hmmm,
let's assume you are in top gear most all the time (otherwise you would be accelerating and it would be about the same).
let's assume gas consumption is about the same through the operating rpm range (to simplify city vs. highway cruising)

So 3.92 to 4.56 would be about a 16% change in rotations. Do you think roughly a 16% drop in gas mileage would be about right?

[ElectricBlueHemi]

You don't need to fix your speedo when changing gears on the ram. The exciter ring on the ring gear is what is used for the speedo and you just use the old one on the new gear set. You only need to change your speedo for tire size change

[Mike_Levy]

Hmmm,
let's assume you are in top gear most all the time (otherwise you would be accelerating and it would be about the same).
let's assume gas consumption is about the same through the operating rpm range (to simplify city vs. highway cruising)

So 3.92 to 4.56 would be about a 16% change in rotations. Do you think roughly a 16% drop in gas mileage would be about right?

Not how it works. In fact, when I changed the gears on my 96 Trans Am, 3.23 to 4.10, the mileage actually went up. Weirdest shit ever.

[Quick]

Hmmm,
let's assume you are in top gear most all the time (otherwise you would be accelerating and it would be about the same).
let's assume gas consumption is about the same through the operating rpm range (to simplify city vs. highway cruising)

So 3.92 to 4.56 would be about a 16% change in rotations. Do you think roughly a 16% drop in gas mileage would be about right?

Not how it works. In fact, when I changed the gears on my 96 Trans Am, 3.23 to 4.10, the mileage actually went up. Weirdest shit ever.

That would imply that assumption (above) is not valid.
I'm thinking most of the mpg difference is going to come from where you spend most of your time in 5th/top gear. Pretty much, when you're cruising at 35 or above you're going to be in top gear. With the rear end change you're going to be going the same speed but turning a couple of hundred more rpm. So if your engine is a lot more efficient up there that might explain it?

[snakejr]

i have a 03 ram and went from 3.92 to 4.56 gears and actualy got better mpg as well as better off the line torque.

[akatoad]

thanks for the info guys. electricblue hemi how does that work, wouldn't the exciter ring turn different speed with different gears and cause your speedo to be off?