2020 Ram 1500 classic 6 in lift and 37’s what’s the best gear ratio to run with this setup??

[Californiaoffroad]

So I just bought a 2020 ram 1500 classic and I’ve got a rough country 6 inch mono tube coil over lift coming. Also have 22x10 rims and 37 inch tires coming. What’s the best gear ratio to bring the truck back to stock ratio with maybe a little more pulling power?

 

[olyelr]

I would go with at least 4.56’s or 4.88’s, but im not up on the half tons to know what is even available.

Is that a 6’4” box?! Looks good…pretty rare with the crew cab!

 

[Californiaoffroad]

Thanks I’ve already got the lift and everything ordered and it’s suppose to be here tomorrow. So 4.56 will be best gas mileage and like stock rpm’s and 4.88’s will have more power and torque but losing a little mpg correct? I just know stock 3.21 gears would bog her down and be rough on her

 

[olyelr]

The gearing for the 8 speed helps a lot in that department…light years better than the prior 6 speeds. That being said, a regear would certainly help get it back to stock feel. Also, not only are the tires quite a bit taller (which obviously throws the gear ratio off), but they will also weigh quite a bit more and most likely have a lot less rolling resistance, which makes it even worse.

 

[olyelr]

if stock is 33’s and 3.21’s, then with 37’s you would only need like 3.73’s to get it back close to the stock overall gearing…but who the hell would do something like that lmao.

 

[olyelr]

 

[Californiaoffroad]

So the stock tire size on my truck was equivalent to a 31.7

 

[olyelr]

So the stock tire size on my truck was equivalent to a 31.7

Stock tires on a 4th gen/5th gen classic are 33’s

 

[Mikethomas]

Thanks I’ve already got the lift and everything ordered and it’s suppose to be here tomorrow. So 4.56 will be best gas mileage and like stock rpm’s and 4.88’s will have more power and torque but losing a little mpg correct? I just know stock 3.21 gears would bog her down and be rough on her

Hope ya ain't go'n on the highway with 4.56s

 

[Mikethomas]

Stock tires on a 4th gen/5th gen classic are 33’s

Stock tires are 33's????????????????????????????????????

 

[olyelr]

Stock tires are 33's????????????????????????????????????

Yep. 275/60/20

 

[olyelr]

Hope ya ain't go'n on the highway with 4.56s

With heavy ass 37’s??

 

[Californiaoffroad]

No the tires i swapped are 265/70 17’s equivalent to 31.7 inches

 

[Californiaoffroad]

 

[olyelr]

View attachment 536643

Ahhhh, yea if you had the 20” wheels they come with 33’s.

 

[olyelr]

also, i will add, with that model truck, even though its a 2020, you really should be in the 4th gen section as that is what the truck really is.

 

[DA Smith]

Sounds like you need 4.56 gears!

 

[ppine]

Nice chart by olyelr.
So it looks like the real answer is 3.90 or 4.10.
4.88s put you at around 2900 rpms going down the highway like old Jeeps.

 

[olyelr]

Nice chart by olyelr.
So it looks like the real answer is 3.90 or 4.10.
4.88s put you at around 2900 rpms going down the highway like old Jeeps.

Id still go at least 4.56’s. Yea the higher 3.90/4.10 gears might be numerically equivalent…but remember, the bigger tires are also much heavier and have less rolling resistance. The truck might roll down the highway comfortably with the smaller/lighter oem tires at highway speeds…but that dosnt mean its comfortable with heavier tires that dont want to roll as nicely (even with a near factory gearing setup).

I guess if i was strictly highway driving i could see that being a better option. But at that point i wouldnt probly be looking at 37’s either (and also at least a lightweight/streatfriendly AT type tire).

 

[DILLIGAF]

I have 4.56 with 37s and it sucks, you want 4.88 at minimum. Heck i put 4.88 on the wife's jeep with 35s and couldnt be happier