Need new tires. Questions about upgrading..!
Stock tires on my truck are 275/60R20 (40lbs). Wrangler SR-A's. They are horrible. I have my eye on Goodyear Duratrac 285/60R20 (59lbs) or Toyo Open Country AT II's in 295/60R20 (62.4lbs). Do yo...
Forum Discussion
Heavier unsprung weight is harder on shocks etc. You may want to go to a stiffer shock with a heavier tire.
Tire diameter matters more for towing power. A larger diameter tire effectively reduces (numerically) your rear axle ratio.
For example, Good year lists the diameter of the 275-60-20 tire at 33". Sice that is stock that becomes the baseline. The diameter of the 285 tire is listed as 33.5".
The formula is old diameter / new diameter x axle ratio. So 33/33.5= .985 x 3.55 = 3.497 effective axle ratio. Said differently, going to 285 tires would be like having a 3.49 axle with your stock tires.
Look at 325 tires and they have a diameter of 35.4. In that case 33/35.4=.932 x 3.55 = 3.30 effective axle ratio.
You can go the other way on the formula too...take a minute and read this tech page from Tire Rack.
My 4.10 axle is now an effective 3.94 after going from 245 to 265 tires. I lost a little power but was OK for me since I have towing capacity to spare.
Tire diameter matters more for towing power. A larger diameter tire effectively reduces (numerically) your rear axle ratio.
For example, Good year lists the diameter of the 275-60-20 tire at 33". Sice that is stock that becomes the baseline. The diameter of the 285 tire is listed as 33.5".
The formula is old diameter / new diameter x axle ratio. So 33/33.5= .985 x 3.55 = 3.497 effective axle ratio. Said differently, going to 285 tires would be like having a 3.49 axle with your stock tires.
Look at 325 tires and they have a diameter of 35.4. In that case 33/35.4=.932 x 3.55 = 3.30 effective axle ratio.
You can go the other way on the formula too...take a minute and read this tech page from Tire Rack.
My 4.10 axle is now an effective 3.94 after going from 245 to 265 tires. I lost a little power but was OK for me since I have towing capacity to spare.
