Question regarding tires....
#1
JK Enthusiast
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I have been looking around and pricing out 35" tires. It has been my understanding that a 317/70/17 is basically a 35" x12.5 tire. So why are most tire brands that carry both a 315/70/17 and a 35x12.50/17 tire have such huge price differences between the two?
#4
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Load rating is part of it. Another part is whether the tires have a rated life and/or warranty. To get longer life, manufacturers have to use a combination of synthetic and natural rubbers. Synthetic is more expensive.
It is also more expensive for the manufacturer to make a lighter tire with the same load ratings.
Lastly, rolling resistance directly affects your gas millage. A heavier tire typically had a higher rolling resistance (lower mpg).
Another part is marketing. Tires specified as <diameter> times <width> are typically for the off-road crowd who might not be as concerned about the above issues. <metric width> / <aspect ratio> tend to be sold more into the consumer market and carry a different set of expectations.
Here's the formula for converting between the two:
- 317/70/17
Width = 317 mm
317/25.4 = 12.48 inches wide
12.48 width times .70 times two (it's a radius) plus 17 inches = 34.4720
Gives 35x12.5 r17
Going the other way:
- 33x12.5 r16
12.5 * 25.4 = 317
33 - 16 = 17
12.5/17 = .74
Gives 317/74 R16
LT317/74 R16
It is also more expensive for the manufacturer to make a lighter tire with the same load ratings.
Lastly, rolling resistance directly affects your gas millage. A heavier tire typically had a higher rolling resistance (lower mpg).
Another part is marketing. Tires specified as <diameter> times <width> are typically for the off-road crowd who might not be as concerned about the above issues. <metric width> / <aspect ratio> tend to be sold more into the consumer market and carry a different set of expectations.
Here's the formula for converting between the two:
- 317/70/17
Width = 317 mm
317/25.4 = 12.48 inches wide
12.48 width times .70 times two (it's a radius) plus 17 inches = 34.4720
Gives 35x12.5 r17
Going the other way:
- 33x12.5 r16
12.5 * 25.4 = 317
33 - 16 = 17
12.5/17 = .74
Gives 317/74 R16
LT317/74 R16