Tires

Many people ask me about tires. I have tried to answer these questions, but since I repeat myself so often, I believe questions about tires are shared by many Willys owners.

Rims

Tires mount on wheels or rims, so you can't really talk about tires without talking about rims. The stock rims were either 16" diameter and 4 ½" or 5" wide. The width measurement is from inside of the lip to inside of the lip. It's pretty tough to measure the inside dimension when there is a tire on the rim, and the ½" doesn't make a big difference anyway. I vaguely remember that the 4 ½" rims were used on wagons and on CJ2A's. The pickups had 5" rims. Reproduction rims are available for about $100 each.

The bolt pattern is 5 on 5 ½. That means 5 lugs evenly spaced around a 5 ½" circle. This same bold pattern was used on Ford trucks. The hole in the center of the rim to go over the hub is about 3 ½". The Ford rims have a slightly smaller hole and these rims won't fit over a locking hub unless the center is cut out. Other than the center hole differences, any 5 on 5 ½ rim will work on a Willys.

Later Jeeps had 15" rims. The width was 6" or 7". These rims will work fine on a Willys. I have a set of 5 rims from a mid 70's CJ on my wagon. I got these at a junk yard for $25 each. The Jeeps after 1987 have 5 on 4 ½" lugs. Several years ago, I found some stock rims that the yard wanted $45 each. I couldn't afford them that day, and when I went back several months later to get them, the owner told me he had crushed the truck! It made me sick. The truck had good fenders, bed, grill, doors and other parts (drive train had been compromised ;-). Why would someone crush a 50 year old historical vehicle to make way for some 10 year old trash that isn't worth nearly as much in terms of aesthetics, intrinsic quality, or long term value? Anyway, if you find stock rims in decent shape, grab them!

Common aftermarket rims are available in 15x7 - 5 on 5 ½. These will work on either a Ford or Willys. I had some used 15x8" chrome spoke wheels on my truck for a couple of years. I traded them to a guy for stock rims. He was happy. I was happy.

Tires

Stock tires were 6.50, 7.00, or 7.50 by 16 bias-ply tires. Many people think that the original tire was the bi-directional, large lug military tread. Some promotional literature from the 50's shows tires that are clearly not this pattern. Since the wheels were the same as the CJ's and MB's, it is possible that some had military tread originally or people chose this tread for their particular use of their Willys.

I had some 7.50x16 bias ply tires on my truck. They are about 30" tall and the 7.50 is inches of tread width. The widest point of the tire is on the bulge of the sidewall and is about 9". Most bias-ply tires use tubes.

Bias-ply tires have a couple of drawbacks:

First, they tend to develop flat spots when sitting. Any tire flattens on the bottom where the weight smashes it. When a warm bias-ply tire cools, it stiffens. When you start out in the morning, you have "square wheel symptom". After a mile or two, depending on temperature, the flat spot goes away.
Second, bias-ply tires tend to deflect off bumps in the road. As you are driving, you notice the vehicle following ridges or cracks in the pavement. Steering takes constant corrections and the wheels wander down the road.

Radial tires have a few important advantages over bias-ply tires. They flatten more, but flex easier, making for lower rolling resistance. The flat spot doesn't stay when the tire is cold. No "square tire" on start up. They handle better, not being affected by unevenness of the road surface. They ride smoother. All in all, they are superior. The whole automotive industry figured this out years ago and all new autos have come with radial tires now for 20 or 30 years.

Popular radial tires tend to be wider than the old bias-ply tires. A typical 15" inch tire is made to fit on a 7" rim and has a tread width of 9". Over the years, people have learned that wider tires are better for traction on pavement. Off-road enthusiast have also favored wider tires for most uses. You can put wide tires on a Willys, but with the following undesirable results:

The tire may stick out past the fenders, spraying water and mud all over your vehicle;
They may rub on the drag link of the stock steering behind the left front wheel.

I had 31x10.50's on 15x8 rims on my truck and experienced both of these problems.

Tall narrow radial tires are available and will work well on a Willys. A 215/85R16 tire will mount on a stock rim and have about the same height and width as a stock tire. They look right, stay inside the fenders and drive much better than bias-ply tires. You probably won't find these tires in stock at most tire stores. Most modern vehicles are made for wider tires. But you can order them. I got some Dunlop Rover R/T 235/85R16 tires from Discount Tire. They work well on my Willys mounted on stock rims. Their minimum approved rim width is 5.5" which the narrowest I have found in any radial tire. That is just barely over the stock rim. They mounted with no problem. I run them tubless. They have large-lug, aggressive tread on the side for mud and snow, but denser tread in the center for highway use. They are rated as 6 ply. Weight rating is E, which means about 3000 lbs maximum load at 80 lbs pressure. My truck weighs about 3600# total, which means about 900# per wheel. I run them at about 25 lbs. to support the normal load. If you do mostly off-road driving, you could get a more open tread pattern for better traction on soft and rough surfaces. If you rarely go off-road, you could get a more dense tread pattern for better pavement handling. Oh yeah, I almost forgot to say that the 235 rubs the drag link, but only in a tight, slow turn, like getting into a parking space. 215/85R16 should be the right size.

5/02