anybody have an opinion? 18" wheels vs. 20"

In 3/4 ton and 1-ton vehicles I prefer higher profile tires on smaller wheel sizes, even preferring 16 inch and 75-85 profiles over the 18 inch. This is because of how I use them, much of the time riding light. The higher profile tire usually has a better ride on small harsh bumps than a wider low profile.

I know low profile tires handle better, and I prefer low and wide on my passenger car, but I don't drive the car and truck the same way. Most larger trucks are going to roll, or trigger the roll stability programming, long before I get to the cornering limits of a 50-series or 40-series tire.

Hybridhunter wrote:
20's should give better handling, less sway, and crisper response. Actually lower profile tires are a better alternative to the perceived squishy handling that all (and almost exclusively) 3/4 & 1 ton truck advocates perceive in "1/2 ton" trucks.
Others have listed possible drawbacks, so I'll leave it at that!

In theory everything you say is correct. In real life I experienced the opposite. I loved the empty handling of my half ton with the 20's but it became very squishy when towing or with a load. That was a major reason why I went to a 3/4 with 18's when I traded.

wintersun wrote:
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A secondary consideration is having a complete tire failure while traveling. Lot easier to find replacement tires at a local shop for the more common wheel sizes.

That's what the spare is for. But a failure on a larger rim, smaller sidewall is much less dramatic, so I would count that as a plus....

Larger rims usually mean a lower profile tire to retain the same overall tire diameter. Lower profile tires flat a lot more easily as their is less sidewall to flex and absorb road shocks.

There are the most high load capacity tires for 16" wheels which are commonly used with commercial vehicles. Fewer exist for 17" wheels and even fewer for 18" wheels. When you get to 20" wheels you are in light truck territory.

The one advantage of 18" over 17" or 16" is that the rims are wider and better support higher load rated tires.

Check this for yourself by doing a tire search and see what is available for various wheel diameter and width sizes for different load ranges.

A secondary consideration is having a complete tire failure while traveling. Lot easier to find replacement tires at a local shop for the more common wheel sizes.

Dunno, but my truck came with factory 20's with P275/55/20 Bridgestone tires, but the spare is an 18" with LT275/65/18 Goodyear Wranger tire on it..

Towing the same TT I towed with my old 97 F150 with 16" wheels on it with LT265/75/16 tires all I can say is the 20's perform better than those LT 16's...

I can corner better and it handles the trailer just fine and I don't see any reason to get LT 20" tires for it at all... :)

It's not the wheel diameter that determines the overall tire height size... It's the size of the tire on that wheel that makes the difference..

My 20's are the same height as my 18" wheel spare and basically the same height as what those 16" wheels were... It's the sidewall of the tire that makes all the difference..

Good luck!

Mitch

For same diameter tires, the 20" lower profile tire will allow less side-to-side squirm, so it will handle better overall in towing situations.

But if you were taking the truck onto rough trails, the extra sidewall flex in the 18s would be better for avoiding punctures.

20's should give better handling, less sway, and crisper response. Actually lower profile tires are a better alternative to the perceived squishy handling that all (and almost exclusively) 3/4 & 1 ton truck advocates perceive in "1/2 ton" trucks.
Others have listed possible drawbacks, so I'll leave it at that!

I have the 20's on my f150, I love the look, but I park in Boston all day long, the curbs are all Granite 4" high. Trying to squeeze and 20 foot truck gets bait close to the curbs. I have scratched my aluminum rims, and wish I had the 18's. As for towing, no opinion, haven't done enough to judge.

I had a choice of 18 or 20 inch wheels when I did my factory order. Both tires are effectively the same diameter so there was no impact on towing. I chose 18s for the wider tire selection and cheaper replacement cost when the time comes.

Our truck has the 20's, but if given the choice I would have taken the 18's based on replacement tire selection. When we first bought our truck, GY had 2 tires available, the stock SRA, the new(er) AT Adventure. Cooper now has one as well (all stock sizing).

I have also wondered if there would be a slightly different ride between the two. Our '10-1500 had 18's LR C 275/65/18, but it is not a fair comparison, to many variables.

I would choose depending on where your travels take you, and tire needs (mostly hwy, or one that is rated for off road/snow) and go from there. See what is available for replacement tires.

But then again, if you buy a truck off the lot sometimes the choices are limited.