3.21 gears and Larger tires

[Truckguy]

I’m trying to get some feedback on anyone running 275/65/20 or bigger tires with the 3.21 gears as I’m trying to decide on the exact tire I need to order. Thanks

 

[kittyjo]

I’m trying to get some feedback on anyone running 275/65/20 or bigger tires with the 3.21 gears as I’m trying to decide on the exact tire I need to order. Thanks

I have 35/12.5/20 nitto ridge grippers they are quite with a little hum but not bad. Definitely have to get a tire recalibrated for the gears tho works a little harder with the 3.21 gears and transmission shift points not adjusted for the bigger tires

 

[puba08]

Have the same size tire and no complaints with the 3.21’s.


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[smckelvey89]

Has anyone noticed a huge performance decrease? I'm between a 305/65R18 (33.6 X 12) or a 295/70R18 (34.3 X 11.6). I also have a 3.5 RC lift waiting to put on

 

[Truckguy]

Have the same size tire and no complaints with the 3.21’s.


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Which tire did you go with?

 

[Krootz]

Subbed, need pics @puba08
Your truck in the profile pic still has the stock tires

 

[puba08]

Subbed, need pics @puba08
Your truck in the profile pic still has the stock tires

Here you go

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[puba08]

Which tire did you go with?

Federal Xplora RT 275/65R20. No rub whatsoever


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[Krootz]

Love the tire choice BTW, this is the same tire and size I decided to replace my AT3WAs with. Thanks for the confirmation pic, def gonna get these tires soon

 

[Neurobit]

Here you go

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Looks awesome.

 

[Truckguy]

Federal Xplora RT 275/65R20. No rub whatsoever


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What kind of lift did you go with?

 

[puba08]

What kind of lift did you go with?

Had the Motofab 2” spacers and Zone UCA’s installed originally. I already had the UCA’s that I never installed on my 4th Gen. Needless to say the ride was absolutely awful with the spacers. All sorts of noises and bangs were coming from the front end. The truck rode like sh!t. I wasn’t expecting the best ride with spacers but saw others raving about them and took the cheaper way out.
So those had to go ASAP! Couldn’t order 5100’s anywhere (which was weird?). So I saw someone mention the Eibach shocks. I new about their shocks and springs from the other forum. So...I ordered them as I didn’t want to wait for the Bils to get restocked in every place I looked. I got the Eibachs for $215 shipped for the pair.
I had them installed (I don’t mess with spring compressors) and the ride is perfect! I highly recommend them. I set them at the 3rd setting (@1.8”) because I have the ORP which nets 1” from the springs. Gave me a 3” lift/level which is exactly what I wanted.
Now if I only went with my gut on the exhaust.....SMH.


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[Catamount50]

Has anyone noticed a huge performance decrease? I'm between a 305/65R18 (33.6 X 12) or a 295/70R18 (34.3 X 11.6). I also have a 3.5 RC lift waiting to put on

I just installed 305/65r18 Nitto Ridge Grapplers along with essentially a 2" level, and if you consider gas mileage as a part of performance, I was surprised at how much my gas mileage was affected. I would estimate at least a 3+ mpg decrease, based off what my dash is saying anyway. If you're asking more about acceleration, I can't say as I don't really have a lead foot anyway.

 

[Krootz]

I just installed 305/65r18 Nitto Ridge Grapplers along with essentially a 2" level, and if you consider gas mileage as a part of performance, I was surprised at how much my gas mileage was affected. I would estimate at least a 3+ mpg decrease, based off what my dash is saying anyway. If you're asking more about acceleration, I can't say as I don't really have a lead foot anyway.

Did you recalibrate your speedo and all that for the new tire size? Might be why you saw such an MPG dip. Might try the “Fuelly” app and see if it’s off

 

[Catamount50]

Did you recalibrate your speedo and all that for the new tire size? Might be why you saw such an MPG dip. Might try the “Fuelly” app and see if it’s off

I have not recalibrated it. I did figure the new size could throw off the numbers, but I wasn't sure by how much. Thanks for that app suggestion. I've never heard of it, but I'll definitely give it shot! And if you have any suggestions on the best way to get that recalibration done, I'd love the advice. Not something I've spent any time researching in the forum yet.

 

[Krootz]

I've heard the dealer can recalibrate it, but I can't confirm that for 5th gens. Honestly, I'd rather pay a couple hundred bucks for the dealer to recalibrate than to get a programmer that does the same thing (and have to undo it every time you bring it in.)
My neighbor got a 2018 and had his 5100s and 34" tires installed at the dealer and they recalibrated his stuff there, so I know it's an option for the 4th gens.

I'd like to someone to confirm whether or not the 5th gen RAMs can have this done because I'll need it pretty soon myself!

 

[smckelvey89]

I just installed 305/65r18 Nitto Ridge Grapplers along with essentially a 2" level, and if you consider gas mileage as a part of performance, I was surprised at how much my gas mileage was affected. I would estimate at least a 3+ mpg decrease, based off what my dash is saying anyway. If you're asking more about acceleration, I can't say as I don't really have a lead foot anyway.

Thanks! I’m not as much worried about the gas mileage because I only drive 3 miles to work. I was worried it would have been sluggish on the highways

 

[Krootz]

Yeah, but you can always fix that with performance upgrades

 

[Catamount50]

Thanks! I’m not as much worried about the gas mileage because I only drive 3 miles to work. I was worried it would have been sluggish on the highways

Well in that regard, I can say there hasn't been a significant difference for me. Certainly not enough to get my attention anyway. And in case I didn't mention it, I also have the 3.21 gears.

 

[kittyjo]

I've heard the dealer can recalibrate it, but I can't confirm that for 5th gens. Honestly, I'd rather pay a couple hundred bucks for the dealer to recalibrate than to get a programmer that does the same thing (and have to undo it every time you bring it in.)
My neighbor got a 2018 and had his 5100s and 34" tires installed at the dealer and they recalibrated his stuff there, so I know it's an option for the 4th gens.

I'd like to someone to confirm whether or not the 5th gen RAMs can have this done because I'll need it pretty soon myself!

I was told that it’s 340$ 140$ in labor and 200$ for the tool or what ever they use but the tire size will stay in the system and under warranty..