Tire width
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Tire width
My wife drove an 8" bolt through the right rear tire. The hole is so big, that the tire has to be replaced. So, I am thinking about replacing the original tires. As I was looking for tires that are 265/70/R17, I noticed they are mostly load range C. I do some occasional towing and thought load range D or E would be better, although, the only tires that seem to be range D and E are 285/70/R17. If my math is correct, the 285's would be about 1 inch wider. Would this cause problems when turning, or is there enough clearance to support this width? Any possible impact to fuel economy?
Thanks,
Joe
Thanks,
Joe
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Originally Posted by n4ziq
My wife drove an 8" bolt through the right rear tire. The hole is so big, that the tire has to be replaced. So, I am thinking about replacing the original tires. As I was looking for tires that are 265/70/R17, I noticed they are mostly load range C. I do some occasional towing and thought load range D or E would be better, although, the only tires that seem to be range D and E are 285/70/R17. If my math is correct, the 285's would be about 1 inch wider. Would this cause problems when turning, or is there enough clearance to support this width? Any possible impact to fuel economy?
Thanks,
Joe
Thanks,
Joe
Actually, 285's would both "wider" and "taller". Any time you increase one of the dimensions of a tire's size without also decreasing the corresponding dimension to compensate, the overall circumference increases.
For 285's, it looks like the circumference would increase by 3.49%, meaning your speedo would read 62.8 MPH when you're really going 65 MPH. Here's the size calculator I used:
http://www.sjdsm.com/tech/tire_size.htm
Given all the fenderwell space, they'll most likely fit (others here might know first-hand) and I don't think this would have a major negative impact on your truck's handling, towing capabilities, gas mileage, etc...but I do question what you're planning on towing which would be so heavy you'd need to switch to a Load Range D or E tire. Load Range C should be more than adequate I would think.
Just my $.02--hope that helps.
Tim
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Good point Tim. I tow my equipment trailer which comes in at 7,800 pounds loaded. I was always told when towing, that a load range D or E is better since the tire is being compressed and the sidewall is taking more pressure when towing. I am not a tire expert, but it sounded reasonable. I have a class IV hitch, so the tongue weight should never exceed 1,000 pounds, which would be 500 additional pounds per rear tire in the worst case scenario. If the vehicle GVWR is 7100 pounds, that would be 1775 pounds per tire, then add 500 for each rear wheel and the total would be 2275. Class C tires are around 2300 pounds max PSI. This of course is the sum of the worst case scenario. Am I drawing the wrong conclusion or going about this wrong?
Thanks,
Joe
Thanks,
Joe
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From: Sacramento, CA
Originally Posted by TimGinCentralNJ
they have some cool calculators! -THX
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Originally Posted by n4ziq
Good point Tim. I tow my equipment trailer which comes in at 7,800 pounds loaded. I was always told when towing, that a load range D or E is better since the tire is being compressed and the sidewall is taking more pressure when towing. I am not a tire expert, but it sounded reasonable. I have a class IV hitch, so the tongue weight should never exceed 1,000 pounds, which would be 500 additional pounds per rear tire in the worst case scenario. If the vehicle GVWR is 7100 pounds, that would be 1775 pounds per tire, then add 500 for each rear wheel and the total would be 2275. Class C tires are around 2300 pounds max PSI. This of course is the sum of the worst case scenario. Am I drawing the wrong conclusion or going about this wrong?
Thanks,
Joe
Thanks,
Joe
Nope, I think you're right on base. The application of the tongue weight on your rear tires will definitely come into play with your tires' Load Range, but at first glance--all your numbers look right. I can't imaging you would have any problems with a "C".
Not wanting to steer you wrong, I'm hoping we'll hear from some other board members, too who might have more experience than me--I always prefer either being proven wrong, or being validated--both are good
Cheers,
Tim G.
