18s or 20s with 37s for towing

[Mulely]

Okay, so I'm 100% aware that with 20s I will have less sidewall and a stiffer tire. However, the only thing I really tow is my boat on a gooseneck trailer, maybe 15k all said. It doesn't sway and the pin weight isn't bar considering most of the weigjt is on the axles. I currently have 37s on 20s and I got no complaints. But I'm not towing every day (maybe 4x a month and 20 miles) and I like the look of 37s on 18s.

For you that have experienced the 18s with 37s, what do you think? Does the 1" sidewall difference really make that much of an issue?

Load capacity on the 18×37" tires is higher than the 20x37s by a couple hundred pounds each, same pressure.

Truck is a 3500 with the factory air.

Sent from my SM-G975U using Tapatalk

 

[BikePilot]

I have 37s on 17" wheels on my 3500 with factory air. Have not towed heavy since installing them, but I have driven around in the mountains with a couple thousand pounds in the bed and it felt rock solid. Tires are Falken RT-01s which are a 128 load index (3900lbs and change).

 

[elephantrider]

I run 37's on 18" wheels and have no issues when towing.

 

[tchur1]

I also run 37s on 18s and have no issues when towing at all.

 

[MI RAM]

I have 35's (not 37's) on 18's and tow a good amount, and I like them a lot! No lift/leveling kit and no rubbing.

 

[LI Guy]

I have 35's on 20's ,no leveling kit on 2500, 14000lbs

 

[DesertRacer]

I swapped from the factory 20”/33s to 18”/37s on my 2022 HO and haven’t had any issues with stability towing my toy hauler fifth wheel that’s typically 12-15K loaded with ~3K pin weight.

There was a small reduction in power though by losing about 10% gearing advantage. I now cruise in 5th instead of 6th and need a little extra throttle to maintain speed in the mountains.

A throttle sensitivity booster helps hide the loss in power, if you don’t already have one.

 

[g00fy]

I have 37s on 17" wheels on my 3500 with factory air. Have not towed heavy since installing them, but I have driven around in the mountains with a couple thousand pounds in the bed and it felt rock solid. Tires are Falken RT-01s which are a 128 load index (3900lbs and change).

Looks great, you running a lift or level? and what offset are the wheels?

 

[BikePilot]

Looks great, you running a lift or level? and what offset are the wheels?

Thanks, 0.5" taller springs up front from Thuren which leveled it out (factory air assist in the back so the rear is lower unloaded than a truck without air). Wheels are 17x9" +18mm offset. I also swapped in 4.10 gears which makes the gearing/power feel like the stock 3.73s in a 4.5 gen Cummins (and a bit better than the 3.42s that were stock in my '18).

 

[phatboy64]

Thanks, 0.5" taller springs up front from Thuren which leveled it out (factory air assist in the back so the rear is lower unloaded than a truck without air). Wheels are 17x9" +18mm offset. I also swapped in 4.10 gears which makes the gearing/power feel like the stock 3.73s in a 4.5 gen Cummins (and a bit better than the 3.42s that were stock in my '18).

Unloaded how many MPEG’s did you loose going to the 4.10s?

 

[BikePilot]

Unloaded how many MPEG’s did you loose going to the 4.10s?

I don't know. Didn't drive it enough with the big tires and without the gears, and just put the gears in so no good data on that yet. These keep in in the stock rpm range for a given speed and gear selection, so should actually help mileage as compared to being geared too tall and lugging everywhere.