FleetOwner - Tires

Mixing G and H Load Rated Truck Tires on Same Axle
Posted by George on April 17, 2007

I seem to remember that the mixing of different ply rated medium radial truck tires was not recommended in years past. Is this still the case? If so, besides not knowing what the inside dual carrying capacity is, what other tread wear and or safety concerns are effected?

I don't think that mixing G and H load range tires would cause any significant problems. If the diameters of the tires are matched within a 1/4 inch and the tread patterns are the same or at least very similar, tire performance and wear should be fine. Structurally, the tires are similar with the higher load range tire capable of running with a highter inflation pressure that allows it to carry a higher load. When inflated to the same inflation pressure, two tires with the same or similar tread patterns should run fine.

G622 in Steer Position
Posted by Lin from Pagosa Springs,, CO, US on April 14, 2007

I have a Ford F450 4X4 on which I just recently put the G622 - 225/75R19.5 tire on both front and rear. The local dealer indicates he sells a lot of these for all positions, fire department 4X4 and oil field trucks, etc. The steering response with these tires seems to be mushy as compared to the previous tire, General LMT460’s. The info Goodyear sent me indicates these are Drive position tires. In terms of steering response would I be better served if I put G149’s on the front? For my winter time use I like the agressive tread (don’t like the noise) of the G622 and don’t really want to change unless the steering continues to be an issue for me. Also, I would like to ask what is the difference between steer position and drive position tire. Is it, from a safety stand point, acceptable to use a drive position tire in the steer position as I have.

We do sell the G622 RSD as a drive tire. Technically, for a 4 X 4 truck, all the wheel positions are driven so, that should be fine. Steer tires are generally have a shallower tread depth and rib type tread designs. It is not surprising that a "lug" type tire might feel a little mushy, especially when new (full tread depth). Internally, steer and drive tires of the same size are very similar so, there is no real reason not to use drive tires on steer axles when the steer axle is driven.

Tires and Rims
Posted by Hien from Corvallis, OR, US on April 13, 2007

I have an 06 honda Civic with the digital speedometer. Originally, the car came with 15″ wheels/rims. I went ahead and replace it with an 18″ wheels/rims.

I understand that with larger tires, the speedometer will show slower than the actual MPH. I was wondering if you can tell me how reliable are the digital speedometer, and if it were to affect my speedometer, how many percent would it affect?

For instance, is it possible that my speedometer is reading 63mph, but my actualy speed is 67-70 mph?

Thank you for your help, and i’m sorry if i couldn’t provide you more information about the tires and such

This is not a truck or truck tire question but, I'm going to take a stab at it anyway. No matter what kind of vehicle you drive, if you don't think the spedometer is correct, it is fairly easy to check. Nearly every highway in North America has markers every mile. Find a friend with a watch with a second hand. Take him or her on a ride down an uncongested piece of smooth, flat Interstate highway (or any limited access highway). Hold your speed at a steady 60 MPH. Have your friend look at the watch as you pass a mile marker. It should take exactly 60 seconds to get to the next marker. If you consistantly reach the next marker in less that 60 seconds, your speedo is reading too slow. If it take longer than 60 seconds, your speedo is reading too fast.

tire question
Posted by jacob from ravenswood, WV, US on April 13, 2007

I have some 18′’x7.5′’ rims, what is the tire size I need for these?

Most people have a tire and wonder what size wheel they need. You seem to have things reversed. I would think there could be many sizes of tires that could fit, the real issue is what will fit under your wheel wells without hitting anything. To answer that, I would consult your car or truck dealer to be sure.

Vintage Goodyear Bias Tires
Posted by Randy from Tucker, GA, US on April 13, 2007

I restore late 60s and early 70s cars and pickups. I found 4 new old stock Goodyear Polyglass Custom Power Cushon G78-15 white wall tires with the marking V-1 DOT and MDVV dot DD3248. Can you help with decoding the date code ? I want to use these for shows of coarse and not for driving all though they are in excellent condition.

It pays to be old. I called a retired Goodyear tire design engineer I know. Just by chance, he happens to be one of the people who designed this tire. The date code on your tire indicates that it was made during the 24th week of 1968 (the 248 at the end of the DOT code). I figured it had to be either a 1968 or 1978 tire and the original designer confirmed that it would have to be 1968.

Search Tires

Q/A Archives

April 2007

Related Experts

Sign-up for RSS

Tires

Archive for April, 2007