Bigger vs smaller tires and wheels

Grit dog wrote:

06Fargo wrote:
As an example if you look at this chart Goodyear offers 16in Duratrac tires with up to 3800lbs load capacity:

Goodyear Wrangler Duratrac

It is a Great Mystery why 17in light truck tires seem to stop at 3100lbs +/-

We bought some take off 18in wheels for our outdated 3500 to get some 3800lbs capacity tires.

I ran 19.5's for a while - they are awesome when you load the truck heavy but less desirable handling and stiffness wise when running around empty. The steel construction is nice and quick for airing up and down vs fabric tires which ride better but are more balloon like...

Toyo 295-70-17 MT is rated for 3950lbs. But yeah the choices are very limited in 17s for some reason. Which is weird since 17s were the new 16 about 15 years ago. Prolly a greater percentage of 17s on the road on HD pickups right now than any other rim size, although 18s in particular and 20s are catching up.

Like the specs on those Toyo's

Steve_in_29 wrote:

jimh425 wrote:
I'm pretty sure the OP was talking about rim size not overall diameter. Ford, for instance, has stock trucks with 3 sizes of rims that I know about with nearly identical outside diameter.

The difference in weight of the rims/tires vs the others in OEM form is probably nominal. Of course, if you go aftermarket, it's a whole different story.

Ford's wheel/tire combos are as follows;
17"/32"
18"33"
20"/34"

Ford has more than 1 tire size in each wheel size. So some of the tire diameters are the same, with different wheel sizes, and some are not, depending on the exact size that is ordered with the truck, which sometimes depends on which option packages the truck is ordered with. It's very confusing.

If you go to the Build Your Own Truck section of Ford's website, you can see which tire and wheel sizes are available with which trucks and option packages.

jimh425 wrote:

Steve_in_29 wrote:
Ford's wheel/tire combos are as follows;
17"/32"
18"33"
20"/34"

Thanks for the specs. I was wrong, and they clearly aren't nearly identical although 3 percent isn't much to me.

An interesting tid-bit, unless something has changed since 2007, if you have the 18" or 20" combos the stock jack WON'T lift the truck enough to replace a flat tire. It goes high enough to get a flat off but NOT to reinstall the aired up spare. Luckily I found this out in my yard and not alongside the road.

Steve_in_29 wrote:
Ford's wheel/tire combos are as follows;
17"/32"
18"33"
20"/34"

Thanks for the specs. I was wrong, and they clearly aren't nearly identical although 3% isn't much to me.

jimh425 wrote:
I'm pretty sure the OP was talking about rim size not overall diameter. Ford, for instance, has stock trucks with 3 sizes of rims that I know about with nearly identical outside diameter.

The difference in weight of the rims/tires vs the others in OEM form is probably nominal. Of course, if you go aftermarket, it's a whole different story.

Ford's wheel/tire combos are as follows;
17"/32"
18"33"
20"/34"

Aluminum is lighter then tire rubber, so a 20" wheel with the same outside diameter tire will weigh less then a 16" wheel(ESPECIALLY if steel as many are) with the same diameter tire.

The OP still hasn't checked back in to clarify the question a poster asked about if he was actually asking about going from 16" to 19.5" setup.

I'm pretty sure the OP was talking about rim size not overall diameter. Ford, for instance, has stock trucks with 3 sizes of rims that I know about with nearly identical outside diameter.

The difference in weight of the rims/tires vs the others in OEM form is probably nominal. Of course, if you go aftermarket, it's a whole different story.

Bigger wheels is harder on the running gear. More leveraged force against trans and U joints.

I would hate to try and get the odometer recalibrated too.

You will get better mileage not spinning larger diameter wheels too.

...I'm always cognizant of out-board weight at the end of axles **gross wheel weight** (the actual weight of the tire and wheel) that will really negatively affect performance/fuel mileage (if there are any Formula 1 racing engineers here, they could explain this better than I LOL!)...

...so, I look at OEM tire + rim weight, then play with any new tire/rim combo, to determine if they will be "heavier" or "lighter" than the OEM set-up...etc...etc.

There is no one blanket statement about 20" wheels and tires.

Many of the tires and rims are just for show and do not have any better load rating than the stock 16" and 17" tires that come on trucks now. In fact, many have a LOWER rating.

It's buyer beware. Bigger is not necessarily better. You have to look at the specifications of the wheels and tires you are interested in to see if they are rated for more, the same, or less than what you have.

19.5" tires are a different animal. They are commercial truck tires and definitely have a higher load rating than stock 16" or 17" tires. They are in no way shape or form related or "close enough" to 20" tires.