18" or 20"?

[Mark Halwa]

The tires I'm looking at have a diameter of 33.2". Will a 35" tire fit a RAM 3500? Not a RAK 3500 - fat little fingers....

 

[LateToTheParty]

The tires I'm looking at have a diameter of 33.2". Will a 35" tire fit a RAM 3500? Not a RAK 3500 - fat little fingers....

The stock Transforce A/Ts are 33.4" diameter, so you will have no problem with the smaller diameter.

And in general, yes, you can fit 35s as well without an issue (though width plus whether or not you'd be keeping stock wheels plays a part in that equation as well).

 

[rossagge]

Not to HiJack the OPs thread here, but curious to know from those with experience of both, how much comfort is sacrificed going to a 20", 295/65R20 vs an 18", 305/70R18. Both are basically 35" diameter. Side wall is just 1" shy on the 20" (7.5") vs the 18" (8.4"). Is that enough to make the ride quality/comfort noticeable? I found some take-off 18" and 20" OE wheels for a good price. Don't want to pay for aftermarket wheel prices. Rather spend that on tires. Ready to get rid of the Trans-Farce tires and steel wheels. Thx.

To edit/add to this, my previous 2500 had 285/65R20's w/the Off-Road suspension (Gasser). Current 2500 wheels are stock 275/70R18 4x4 (no Off-Road) (Diesel). I do notice the ride quality improvement on my current 2500 Diesel. Side wall difference is the same, just shy of 1" more, but no Off-Road package. So apples to apples suspension, would 1" of side wall make a difference?

 

[Wmhjr]

In every instance of every vehicle where I've changed wheels, going to a larger rim with a reduction of sidewall did impact the ride. How much is hard to describe, given that each tire can have its own characteristics, etc. But at the end of the day, even a 1" reduction has measurable volume reduction, so if the sidewalls are relatively consistent stiffness, etc, it would be an impact. OTOH, I have no issues with the OEM tires, so....

 

[rossagge]

In every instance of every vehicle where I've changed wheels, going to a larger rim with a reduction of sidewall did impact the ride. How much is hard to describe, given that each tire can have its own characteristics, etc. But at the end of the day, even a 1" reduction has measurable volume reduction, so if the sidewalls are relatively consistent stiffness, etc, it would be an impact. OTOH, I have no issues with the OEM tires, so....

Thanks for that. Been leaning towards the 18" with a taller tire. More ammo for my decision.

 

[Mark Halwa]

Not to HiJack the OPs thread here, but curious to know from those with experience of both, how much comfort is sacrificed going to a 20", 295/65R20 vs an 18", 305/70R18. Both are basically 35" diameter. Side wall is just 1" shy on the 20" (7.5") vs the 18" (8.4"). Is that enough to make the ride quality/comfort noticeable? I found some take-off 18" and 20" OE wheels for a good price. Don't want to pay for aftermarket wheel prices. Rather spend that on tires. Ready to get rid of the Trans-Farce tires and steel wheels. Thx.

To edit/add to this, my previous 2500 had 285/65R20's w/the Off-Road suspension (Gasser). Current 2500 wheels are stock 275/70R18 4x4 (no Off-Road) (Diesel). I do notice the ride quality improvement on my current 2500 Diesel. Side wall difference is the same, just shy of 1" more, but no Off-Road package. So apples to apples suspension, would 1" of side wall make a difference?

I don't think you are hijacking - that was actually my next question. Any more responses would be much appreciated!

 

[JABLures]

The KO2s are a great tire, only thing I don't like about them is the square edge they have. I feel they catch the edge on asphalt more than a rounded edge tire.

I've used KO2's for the past 20 years and always had good luck with them, especially on slick clay. On my 2005 2500 Cummins I got about 70K miles out of them each time and sold the truck with it's 4th set on it. I've been reading that some folks are seeing a lot of premature wear on 4th generation trucks so I'm holding off buying a set until I figure out if it's the 20" rim driving the problem (different design?) or the something to do with the truck itself. If its because the 20's are the culprit, then I'll be getting 18's so I can put the KO2's on.

 

[H3LZSN1P3R]

I've used KO2's for the past 20 years and always had good luck with them, especially on slick clay. On my 2005 2500 Cummins I got about 70K miles out of them each time and sold the truck with it's 4th set on it. I've been reading that some folks are seeing a lot of premature wear on 4th generation trucks so I'm holding off buying a set until I figure out if it's the 20" rim driving the problem (different design?) or the something to do with the truck itself. If its because the 20's are the culprit, then I'll be getting 18's so I can put the KO2's on.

K02’s have only been out for 6.5 years mid 2014 they were released so how did you get them 14 years before they were made....

 

[kobra]

Not to HiJack the OPs thread here, but curious to know from those with experience of both, how much comfort is sacrificed going to a 20", 295/65R20 vs an 18", 305/70R18. Both are basically 35" diameter. Side wall is just 1" shy on the 20" (7.5") vs the 18" (8.4"). Is that enough to make the ride quality/comfort noticeable? I found some take-off 18" and 20" OE wheels for a good price. Don't want to pay for aftermarket wheel prices. Rather spend that on tires. Ready to get rid of the Trans-Farce tires and steel wheels. Thx.

To edit/add to this, my previous 2500 had 285/65R20's w/the Off-Road suspension (Gasser). Current 2500 wheels are stock 275/70R18 4x4 (no Off-Road) (Diesel). I do notice the ride quality improvement on my current 2500 Diesel. Side wall difference is the same, just shy of 1" more, but no Off-Road package. So apples to apples suspension, would 1" of side wall make a difference?

I believe the difference will be noticeable. Go here to check it out:

Wheel Offset Calculator

Use our wheel offset calculator to visualize the new tire position when changing wheel and tire sizes. Convert wheel offset and backspacing to calculate the correct setup for your vehicle.

tiresize.com

The difference is ~12% more sidewall in the 305/70/18 compared to 295/65R20.
I shared my experiences a few posts back on going from the stock 285/65R20 to 295/70R18. VERY noticeable improvement on my 3500.

And, I think you are already proving the point; you are seeing a noticeable difference with the current truck even though the sidewall difference is only 4% more than your past truck.

B

 

[rossagge]

I believe the difference will be noticeable. Go here to check it out:

Wheel Offset Calculator

Use our wheel offset calculator to visualize the new tire position when changing wheel and tire sizes. Convert wheel offset and backspacing to calculate the correct setup for your vehicle.

tiresize.com

The difference is ~12% more sidewall in the 305/70/18 compared to 295/65R20.
I shared my experiences a few posts back on going from the stock 285/65R20 to 295/70R18. VERY noticeable improvement on my 3500.

And, I think you are already proving the point; you are seeing a noticeable difference with the current truck even though the sidewall difference is only 4% more than your past truck.

B

Thanks much. I will definitely pull the trigger on a set of 18"s as soon as I find something I like.

 

[JABLures]

K02’s have only been out for 6.5 years mid 2014 they were released so how did you get them 14 years before they were made....

I had the KOs. I only had one pair of the 2nd generation. I looked at them as the same basic tire with some subtle differences. I like the rim edge on the originals and I like the side cleats on the new one but to me they're the same basic tire.

 

[Hawk375]

A little visual comparison between my stock 20” to 18” wheels with 295/70r18 tires

Sent from my iPhone using Tapatalk

 

[Mustangmike66]

A little visual comparison between my stock 20” to 18” wheels with 295/70r18 tires

Sent from my iPhone using Tapatalk

Hawk375 what’s the difference in the ride and towing assuming you towed with both? Also, what’s the make and model of those rims? Thanks for your help.


Sent from my iPhone using Tapatalk

 

[Jackmup]

I went with 20" Toyo open country AT3 they are similar to the KO2 tread pattern and at 50psi it rides nice, Carli recommends 45 but you have to reset the tpms warning threshold first. ( Can't do it after it's triggered have to reinflate then set threshold then deflate)

 

[T_J]

So, maybe a bit of a different take; I have a 2020 3500 ltd with the 20" rims that I upgraded from a 2016 2500. The 3500 is not nearly as rough riding as 3500s I've had in the past, but it was still noticeably rougher ride on any sharp ridges or bumps in the road than the 2500. (Up here in Canada in the winter it's frost heaves; down south you might have expansion cracks on the highway).
So, I began to do some research. Companies like CJC, Carli and Thuren all say that 20" rims are a bad idea if you want a smooth ride; in fact some say they wonder why manufacturers even offer them. I know those guys are off road biased, but they still do talk a lot about ride quality. And they recommend 18" for mostly highway trucks and 17" for mostly off road.
One other note is that I tow a heavy, ~17000lb 5th wheel, so no way would I go to a tire that was too soft or that had a lower weight capacity.

I ended up going with Fuel Blitz D674 18x9 rims and Falken Wildpeak AT3W LT295/70R18. The tires and wheels actually have a higher load capacity than OEM. And, the improvement in ride quality is very noticeable; far more than I expected! I would say that it made the empty ride quality of my 3500 improve to be almost as good as my 2500.

I am absolutely pleased with the choice and would highly recommend it. And, this from a guy who has not bought aftermarket rims for a truck for probably 20 years.

Here's a photo.
hth,
B

I appreciate this info as I have a ‘22 3500 4x4 SRW Limited that I want to put the same tire & wheel package you chose. Wheels are on the way so I hope they fit as I too wanted the look & a little more sidewall to improve ride quality. I went with the Carli 2.5” lift kit and their sway bar as the reviews were favorable especially for city driving.

 

[菠萝啤]

刚刚订购了 2021 年 RAM 3500 SRW，我希望在到达时更换库存轮辋/轮胎。感谢您对是否使用 18 英寸还是 20 英寸车轮的任何想法/建议，为什么？

它将主要在高速公路上行驶，牵引一辆旅行拖车。

我将RAM5500上的轮胎型号更改为365/80R20

 

[T_J]

I appreciate this info as I have a ‘22 3500 4x4 SRW Limited that I want to put the same tire & wheel package you chose. Wheels are on the way so I hope they fit as I too wanted the look & a little more sidewall to improve ride quality. I went with the Carli 2.5” lift kit and their sway bar as the reviews were favorable especially for city driving.

I appreciate this info as I have a ‘22 3500 4x4 SRW Limited that I want to put the same tire & wheel package you chose. Wheels are on the way so I hope they fit as I too wanted the look & a little more sidewall to improve ride quality. I went with the Carli 2.5” lift kit and their sway bar as the reviews were favorable, especially for city driving.

 

[kobra]

@T_J - looking good!

B