Question about air pressure with 35's
10-04-2010, 10:32 PM
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Question about air pressure with 35's
Recently got my Goodyear Wrangler Duratracs put on and was wondering what you guys were running air pressure wise in these? They are 315/70/17. Thanks
10-05-2010, 03:43 AM
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10-05-2010, 04:33 AM
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Here is a real simple way to figure out a starting point for new tire inflation.
Look up the Service Description of the OEM tire. For instance lets take a Goodyear Wrangler SR-A with a 113 Service Description.
Check the tire inflation rate on the door Placard. It can be different for different vehicles and installed option, but for demonstrative purposes lets say it reads 35psi.
Now take the Service Description of the new tire. Lets use a BFG KM2 35x12.5x17 with a Service description of 119.
Subtract the new Service Description number from the OEM Service Description number and we end up with -6. Reduce your new tire psi by this amount and it will give you a decent starting point to find the appropriate inflation rate.
There are more exacting ways to do this, but this is very close and reliable. It also gives you a tire spring rate that matches your stock spring rate. Most importantly it is where the manufacturer believes your tire inflation rate should be set to insure your safety. For more exacting numbers you can use an ETRTO inflation rate table.
Look up the Service Description of the OEM tire. For instance lets take a Goodyear Wrangler SR-A with a 113 Service Description.
Check the tire inflation rate on the door Placard. It can be different for different vehicles and installed option, but for demonstrative purposes lets say it reads 35psi.
Now take the Service Description of the new tire. Lets use a BFG KM2 35x12.5x17 with a Service description of 119.
Subtract the new Service Description number from the OEM Service Description number and we end up with -6. Reduce your new tire psi by this amount and it will give you a decent starting point to find the appropriate inflation rate.
There are more exacting ways to do this, but this is very close and reliable. It also gives you a tire spring rate that matches your stock spring rate. Most importantly it is where the manufacturer believes your tire inflation rate should be set to insure your safety. For more exacting numbers you can use an ETRTO inflation rate table.
