Technical Radial Tires for 1947 Ford

I'm wanting to use 15" Ford wheels and Radial Tires on my 1947 Ford Business Coupe. Car is 100% stock. I have a complete set of mid-fifties Ford 15" rims that will fit the '47 Ford, but I'm not sure of the correct Radial tire that will fit without any issues. Any help is appreciated. Thanks

 

Here is the Coker cross reference chart.

https://www.cokertire.com/blog/tire-size-cross-reference

Lots of issues to consider:

The width of the original 1947 wheels vs the width of the mid-1950's wheels.

The offset of the original 1947 wheels vs the width of the mid-1950's wheels.

 

They must be truck wheels.
I think you will find P-235-75-R15 to be about right.
Personally, I like the bias-plys on my coupe. No issues so far. I like how they look and how the car drives, but that's just me.

 

235-75-R-15 tires would be the right diameter to sync with your speedometer but not knowing the width of your wheels I can't say if you have enough fender clearance. 5 1/2" or 6"wide would be no problem. You can also get a little more fender clearance by choice of wheel back set. You should be able to get 4" back set with no problem.

 

radials will make it steer like a broken tank at slow speed.

 

@charles williams

Having had the same model Ford as you, I would recommend either 215 or 225 max section width.
None of the previous recommendations are going to be the same diameter as a 6:00-16 and they are in the 80 to 83% aspect ratio range. And, you can easily get a speedometer correction ‘box’ to put inline with speedo cable. IMO, a 225/75-15 would be a ‘good’ compromise. Sort of the ‘Goldilocks’ choice.

p..s. yes, the radials will increase steering effort a little when parking, but the ride and handling improvements, which are realized when driving, which by far exceeds parking time, is worth the small effort increase when parking. Frankly, those that praise the ‘great handling’ of their bias plies wouldn't know ‘good handling’ if it bit them on the ass! But, if they are happy, I am happy for them.

Ray

 

Call Diamondback or go online and look at their Auburn Deluxe tires. Radial tubeless in the vintage tire sizes. They have the vintage look but have all the benefits of a modern radial tire. I have a set on my 32 Coupe and could not be happier with the look and performance. They are smooth and round and need very little balancing.

 

I use 215 75’s on the rear and 205 75’s on the front of a 56 and they are perfect. I’d think 235’s may be too large but it your using 4:11 gears they would be fine. If you could find an 85 aspect ratio they would be the closest to the original width.

 

235's will look like a 4x4.

Consider the Diamondback Auburn Deluxe radial 6.70/15

 

A bit dramatic....it will look like a truck maybe but not a 4x4

 

Physically measure diameter of one of your stock-sized tires as mounted, then find a matching-diameter replacement or as close as you can get. A 'typical' 235/75R15 tire will be just under 29" in diameter, there will be minor size variation between brands. Those charts always end up giving a smaller-than-OEM-diameter in my experience, plus in your case don't cross from a 16" tire. No matter what you buy in a 'off the shelf' tire, it won't match your OEM tires in all dimensions, you have to pick just one, diameter is always my choice. A 235/75R15 will fit the rear no problem, I've got even larger 265/70r15 on the rear of my avatar with no clearance issues. Those won't fit the front of mine, but mine is also heavily lowered; on a stock-height car they should clear no problem although you may have slight rubbing at full lock turn.

The other issue is rim width. A 235/75R15 will require a 'recommended' minimum rim width of 6", I'd be hesitant to install them on anything narrower. In a pinch I'd use a 5.5" wide wheel, no narrower than that though. Note that rim width is bead area-to-bead area, not the overall outside-to-outside measurement.

Given the greater availability of 16" tires these days, that may be worth exploring but rim width will still be an issue.

 

Had a 46 coupe with 205 front and 215 rear. Handled great rode great and drove nice

 

I have 215/75-15 radials on the front of my car, I have to put 34 psi or it steers like a tank in parking lots. A good analogy.

 

Go with Diamondback. Not cheap, but great radial tire with the vintage look.

 

The 235-75r-15 seem way big to me. But if they match the circumference of the stock tires...you have a dilemma. Going to a smaller circumference tire will have that flathead screaming out on the hi-way, besides not looking right. Good luck..
Wish I had an answer for you.

 

May be apples and oranges, but my 47 Lincoln has 215-60R-15 on front and 255-60R-15 on back. Even with a worn out steering box with a half a round of play it steered good, even at parking lot speeds. Just had to turn the wheel a bunch of times in tight spaces, but with the big wheel for leverage it wasn't too bad. Now with power steering, the next set of tires will probably be 225-70 on front for a little more height to fill the fender a bit better, and might use 275-60 on the back for a little more rake.

 

Hear, Hear!

I've found when folks switch from Bias-Ply to modern Radials they do not adjust air pressure accordingly.
6.7-15 BP tires need ~25Psi.
205/75 R15 tires need ~35Psi.
Put 25psi in a radial it will wallow on the rim and feel like rolling on marshmallows, tread cups like a BP under load.

Not sure what the 'busted tank track' comments are relating to.
If you are cranking on the steering wheel without rolling the car, might want to re examine driving habits, that's blue hair technique.

It is easier to rotate a BP tire when unloaded it has a smaller contact patch(egg shape) than a radial(rectangle). So there will be more effort needed in steering. Best to simply roll the car while turning the steering wheel. Takes a lot of stress off the steering gear.

 

People are so used to power steering they forget this.