Downsizing Wheels on 2020 Ram 1500 Big Horn

[Haystacks]

I did some searching and couldn't find this exact issue addressed. I have a 2020 Ram 1500 Big Horn 4x4 Ecodiesel, and I'm looking to give it a moderate off road set up. Nothing crazy, just a 3.5" lift with 35" tires. It comes stock with 20" rims, and when I told the guy at the off road shop I was looking to downsize to 17", he said that's a no go. They had a 2020 Rebel in the shop and were trying to put 18" wheels on it. They had to grind down a particular spot on the outside of the brake calipers to get the 18" wheels to fit. When I called a couple Ram dealerships and spoke to the service department, they confirmed that there is not an aftermarket 18" wheel that will fit my truck. Has anyone here found an 18" wheel that can successfully replace the stock 20"?

 

[CheechDogg.0n37s]

Here is a list of the 18" wheels that will fit your 2020

1. Vision Rocker 18x9 -12 offset
2. Fuel Rebel 18x9 -12 offset
3. Fuel Zephyr 18x9 +1 offset
4. Fuel Clash 18x9
5. Fuel Trophy 18x10 -12 offset
6. Method Envy 18x9 -12 offset
7. Method MR305 18x9 -12

Look for wheels that are 18x9 with -12 offsets ... You wont have a problem with them .. Those dealerships are full of $Hlt!!!

 

[CanRebel]

I did some searching and couldn't find this exact issue addressed. I have a 2020 Ram 1500 Big Horn 4x4 Ecodiesel, and I'm looking to give it a moderate off road set up. Nothing crazy, just a 3.5" lift with 35" tires. It comes stock with 20" rims, and when I told the guy at the off road shop I was looking to downsize to 17", he said that's a no go. They had a 2020 Rebel in the shop and were trying to put 18" wheels on it. They had to grind down a particular spot on the outside of the brake calipers to get the 18" wheels to fit. When I called a couple Ram dealerships and spoke to the service department, they confirmed that there is not an aftermarket 18" wheel that will fit my truck. Has anyone here found an 18" wheel that can successfully replace the stock 20"?

My 2021 Rebel come with 18 from Factory.
I put 20's on my truck.

Both dealer and off road place you went to are stupid. As it was mentioned above. there are many that would fit.

 

[Haystacks]

Thank you both for your help.

 

[brian42]

OEM 18" wheels will fit since they are the same brakes on on all trim levels (don't know about the TRX though).

The don't clear the calipers by much but they do fit (I have 18" OEM wheels).

You have to be careful with aftermarket wheels as they might have clearance issues based on their specs (as you have read above).

18" is the smallest you can go. My 18s clear the caliper by 1/4" - 3/8" inch.

 

[Quick_Shifter]

I originally put 18’s on @b8ascrub truck with a 2” leveling kit and 35 x 12.5’s so I can absolutely confirm 18’s can be done. Now his truck has a 6” lift riding on full length fox 2.5 coilovers with reservoirs dialed in with the same wheel and tire combo

 

[brian42]

OEM 18" wheels will fit since they are the same brakes on on all trim levels (don't know about the TRX though).

The don't clear the calipers by much but they do fit (I have 18" OEM wheels).

You have to be careful with aftermarket wheels as they might have clearance issues based on their specs (as you have read above).

18" is the smallest you can go. My 18s clear the caliper by 1/4" - 3/8" inch.

I revise my statement. After looking at the clearance this weekend I've got 1/8" at best between the caliper and wheel.

The tape weights my shop uses to balance my wheels go off-center inside the rim otherwise they would probably rub on the caliper.

 

[aeromax4]

My 2020 Laramie came with 18's and I'd like to upgrade to OEM 20's. Would this change affect the computer or the calipers? TIA

 

[Rlaf75]

My 2020 Laramie came with 18's and I'd like to upgrade to OEM 20's. Would this change affect the computer or the calipers? TIA

As long as you use the factory size 20" tires you should have no problems. The overall diameter of the stock size 18" tires are the same as the stock size 20" tires. The 20" tires have a shorter sidewall than the 18" tires but the overall diameter will be the same. My ram came with 20" and I swap to 18" for the winter and the speedometer is exactly the same for both. I checked with a GPS to verify

 

[aeromax4]

Thanks for your response. I'll look up the tire size.

 

[aeromax4]

Thanks for your response. I'll look up the 20" tire size.

 

[Ssamt75]

I revise my statement. After looking at the clearance this weekend I've got 1/8" at best between the caliper and wheel.

The tape weights my shop uses to balance my wheels go off-center inside the rim otherwise they would probably rub on the caliper.

Do you happen to know if 285/65/18 will fit factory wheel without contacting upper control arm. Seems like they will.

 

[brian42]

Do you happen to know if 285/65/18 will fit factory wheel without contacting upper control arm. Seems like they will.

I wouldn't think so. The Rebel runs that size.

The wildcard is the wheel. The OEM 18x8 is the smallest wheel that fits so there's not much wiggle room outside of OEM specs for an 18" wheel.

My Big Horn had 275/65-18 tires and had some room to "breathe" on the stock 18" wheel. With the Rebel only have a +1 tire on the same 18" wheel (same specs, different visual design) there shouldn't be any rub unless you start modifying the suspension also.

 

[TestPilot57]

You have to be careful with aftermarket wheels

Key point.

Aftermarkets are not just "18 x 8", 18 x 9", 18 x 10" etc. The dimensions spec'd are for the ID of the TIRES. In addition to offsets, there is the profile of the metal that makes the wheel.

 

[drmoreau]

Thanks for your response. I'll look up the 20" tire size.

The wheel specs and tire sizes are on the inside of the driver door opening. Its an analog fix

 

[brian42]

OEM wheel specs:

2020 Ram 1500 - Wheel & Tire Sizes, PCD, Offset and Rims specs

Wheel size, PCD, offset, and other specifications such as bolt pattern, thread size (THD), center bore (CB), trim levels for 2020 Ram 1500. Wheel and tire fitment data. Original equipment and alternative options.

www.wheel-size.com

 

[aeromax4]

The wheel specs and tire sizes are on the inside of the driver door opening. Its an analog fix

I put a set of 275/55/20 with sensors. Great fit.

 

[drmoreau]

My truck came with 20" wheels but I want more sidewall height so I can air down offroad. Has anyone tried the LT235/80 R18 size without it rubbing? My 1500 crew cab truck came with the offroad package, but I've searched and am not sure if it has the 1" lift like the Rebel. Anyway, I've bought some 18" factory wheels and am looking at tires. The BF Goodrich All Terrain are E rated and have three ply sidewalls. I live in the west and we see a lot of sidewall cuts from rocks in the desert. The Falken Wildpeak is also a good tire, and could this size might work: 33x12.50R18LT Anyone have experience with it?

 

[RamDiver]

My truck came with 20" wheels but I want more sidewall height so I can air down offroad. Has anyone tried the LT235/80 R18 size without it rubbing? My 1500 crew cab truck came with the offroad package, but I've searched and am not sure if it has the 1" lift like the Rebel. Anyway, I've bought some 18" factory wheels and am looking at tires. The BF Goodrich All Terrain are E rated and have three ply sidewalls. I live in the west and we see a lot of sidewall cuts from rocks in the desert. The Falken Wildpeak is also a good tire, and could this size might work: 33x12.50R18LT Anyone have experience with it?

My Warlock came with 20" alloy wheels, and I added a set of OEM 17" steel rims for winter tires.
Gen 4 uses 17" while Gen 5 uses 18".
I have E-rated 245/75R17 BFG AT KO3s. Who makes an LT235/80R18?

It's not so much the smaller tire that's going to rub, but the smaller rim might contact the calliper or calliper mounting brackets.

Check your spare rim size for a clue on the minimum size. Either 18"x7" or 18"x 8", if I were guessing.

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