Tire Size for stock wheel:

[40ford]

Since there is plenty of 16 inch radial tires out there today,I was just wondering what would be the best and biggest size tire(radial) for a stock 40 wheel with out causing any problems?I am looking for just black walls.My Cokers are aging and time to change!Looking to keep same size on front and rear.I figure you don't have to pay over $200 a tire to get just a decent tire for a driver car without buying a reproduction tire?

 

[rotorwrench]

The width of the rim will have a lot to do with what width tire you select. The 1940 wheels were available in two widths. Tires were built differently in that era. The aspect ratio isn't all that different but the tread widths were a lot smaller on the old prewar and immediate post war tires. The early narrow wheels work best with narrow tread widths and the wider rim works with a bit wider tread width but they really don't compare well with modern radials.

Modern radials have several normal modern tread widths that are inexpensive due to being popular sizes, Less popular widths tend to increase in price a good bit. A 6-inch width may be about as wide as a person would want to go on a narrow rim and that equates with around a 155-mm width. A 5-inch tread width is around 127-mm so a person will have to settle for a happy medium somewhere. Popular widths in the modern era are wider than that. Aspect ratio would likely be around 70 to 80 to get close to the original aspect ratios back in the day.

A person may find that lower aspect ratios change the speedometer calibration and slow the car down due to smaller overall diameter of the tire so choose carefully. You may find that there aren't that many choices in the sizes you may want. Stay away from the spare rated tires.

Compare Diamondback and Coker. At least these have original sizes in radial or biased ply.

 

[GB SISSON]

I have been running 215 85r 16s on my woodie. They often come stock on dually pickups and are widely available. This is a narrow tread with an 85 aspect ratio.(Tall and skinny). I bought 4 like new 'take-offs' from a dually pu guy wanting to go to big off-road wheels and tires. Paid 150.00 for the set. I run them tubeless on what I think are stock 47 pickup wheels. I would never go back to bias ply tires as it steers easily and tracks well down the road with a comfortable ride. I priced a similar sized radial at a classic tire specialty house for something like 265.00 each. There is one similar tire called something like 'excalibur?' that I would love to run if I had a bunch of extra money to spend on my hobby trucks, but these 215s are a huge improvement over the bias. Edit: In reading the previous post, the 'excalibur' were 'Diamondback'.

 

[RB]

Ck. the Cooper Trend Setter line, clean side walls & 235x15's were $88 not sure on 16"

 

[V8COOPMAN]

Since there is plenty of 16 inch radial tires out there today,I was just wondering what would be the best and biggest size tire(radial) for a stock 40 wheel with out causing any problems?I am looking for just black walls.My Cokers are aging and time to change!Looking to keep same size on front and rear.I figure you don't have to pay over $200 a tire to get just a decent tire for a driver car without buying a reproduction tire?

700-R16s all day long....'40-'41 wheels are 4" wide. '42-'48 wheels are 4-1/2" wide and will easily accept 7.50-R16s, but they are almost TOO big looking. DD
.

 

[frnkeore]

While it's not to dangerous to run wide sidewall tires on narrow wheels, there are things to consider.

These cars ran a aspect ratio of 1/1, meaning the side wall was as tall as it was wide. The factory recommended wheel width to tire width, was 2" wider tire, that wheel. i.e. 4" wide wheel and a 6.00 tire. That 2" wider tire than wheel, still, mostly applies today.

In tire catalogs, it will list the narrowest wheel to be used with a tire and in general, they won't mount it on anything narrower. There are exceptions to that I have a couple of places here, in my area.

1" is 25.4mm, you can round that off to 25 for this stuff. So, a 4" wheel is ~100mm and what the factory would recommend is would probably be a 155 wide sidewall. I think, personally, that a 185 is ok. What happens is that if you go much beyond that, is with normal air pressure, the tire will crown and you will loose tread contact and sidewall stiffness to some degree.

There is no problem getting the right tire width today but, it's the sidewall height is the issue, I don't see any 185 metric tires with more than .80 aspect ratio and that's even hard to find.

The 215/85/16 is a good tire but, is for trucks (that's what is on my F350) but, should be run on at least a 6" wide wheel.

Also, keep in mind, that a 215 tire, is a 8.50 size tire and in car applications, you can run into fender problems. The 185 size is a 7.25 size.

I did find 185/80/16 tires but, they are 6 ply trailer tires, they are 27.65 tall. Close to original size and only 1 1/4 wider. The 215/85/16 is 30.39 tall and 2 1/2 wider.

 

[frnkeore]

Besides the 7.00x16, there is also some 6.50x16's, they are both truck tires.

Another option is the car, 215/70/16. I wouldn't put it on anything narrower than 5.5 wide wheel. It's 27.85 tall but, would have a more modern look and maybe fender clearance issues.