The Stovebolt Site Forums The Shop Area General Truck Talk Tires & Wheels

Hello all,

New guy here, have a question about tires & wheels for anyone with some insight. I just bought a '65 shortbed stepside that currently has 15 inch wheels with 235/75-R15s. I bought a set of 17x8" Rallye's and am wondering if a 225/55 R-17 will support the truck, or would I be better off with a 235/65. I won't be hauling large loads and I like the look of a low profile tire, but don't wanna take a chance. I've been getting mixed reviews from different tire stores. Some say the 225/55 is OK, some say the tires would be overloaded.

Any help - GREATLY appreciated.

tim

Should say one the tire what the max load is and at what PSI. You want that to be more than 1/4 of what the max gvw of your truck is. Or better put, the max load on the tire X 4 should be over the total weight you ever expect your truck to weigh when loaded and even when overloaded.

Grigg's on the right track, but you must also consider that most tires list the max load at a given pressure, usually between 44-50 psi on low profile tires. You wouldn't want to run that high of pressure as the ride and handling qualities would be very poor. I have seen where a local kid wanted the 225/55/16 on a '72 3/4 ton. He was back within a week with a blowout from insufficient load capacity. The 4 tire together was barely enough for the weight of the empty truck. They also caused problems in the drivetrain from excessive rpm (307, sm465 trans, ans a 4.56 rear) from the tire diameterbeing too small.
Personally, I'd suggest going with the 235/65/17 as they are available in a truck rated tire that can handle the load at a reasonable pressure (35 psi). The 225/55/17 would have to run at 45 to get a close rating, and that is actually lower.

If you don't mind a truck riding like a truck then don't worry about the high air pressure, as long as you are under the max written on the sidewall.
I run 8R19.5 tires on my 1 ton, I fill them to 75PSI when empty and about 90 or 100 when loaded, they are rated for more than that.

What ever you decide to use be sure you don't overload them, and I personally want a pretty large safety factor / tire capacity compared to loaded vehicle weight.

Thanks Guys!

I think I'm gonna go with the 235/65 R-17s, just to be on the safe side. When I get the truck, I'll post some photos in the gallery. (I bought it on E-bay and am still waiting for it to show up.) I'm having a hell of a time not buying everything I want for it until AFTER it arrives. The new rims are already ordered, along with chrome bumpers, new grill, new mirror, other little stuff. Thanks again.

Hey Olchevynut, where in Wyo? I'm a native. So is my truck.

Hey Bigmacdaddy,

I've lived in Rock Springs for about 15 years, but originally grew up in Sheridan. Funny, I've got a SUBE too. Gotta tell ya, I love this forum stuff. A plethora of knowledge. Did I read right, you're in Seattle now?

Tim