Tire Pressure
Posted: Sun Mar 06, 2011 10:33 am
My Heep will never be a "fuel efficient vehicle" 
but every little bit helps
I've tried different tire pressures over the last year or so and all that I can say for sure is, lower pressures = lower mileage. But what's the 'recommended' pressure when you're running larger-than-factory tires? I found this on JeepForum.com. Anyone know if this is a good way to figger it out, or have another way?
Originally Posted by Muddeprived
Take the max weight that the tire can support (on sidewall) and multiply that by 4. This gives you the total weight that all four tires can support. Next take the weight of your jeep and divide that into the total weight. You should get around 1.8-2 something. Now divide this number into the max psi stated on teh sidewall and you'll have your ideal air pressure. most 31" or taller tires can support light-truck weighted applications and jeeps are just too light, requiring only 1/2 of the max psi.
For instance:
2000 lbs at 50 psi max
2000 x 4 = 8000
My 4 cyl's jeep weight with add-ons: 3800 lbs
8000 / 3800 = 2.1
50/2.1 = 23.8 psi
It's best to set the front tires a little higher due to the engine weight.
25 front 23-24 rear
but every little bit helpsI've tried different tire pressures over the last year or so and all that I can say for sure is, lower pressures = lower mileage. But what's the 'recommended' pressure when you're running larger-than-factory tires? I found this on JeepForum.com. Anyone know if this is a good way to figger it out, or have another way?
Originally Posted by Muddeprived
Take the max weight that the tire can support (on sidewall) and multiply that by 4. This gives you the total weight that all four tires can support. Next take the weight of your jeep and divide that into the total weight. You should get around 1.8-2 something. Now divide this number into the max psi stated on teh sidewall and you'll have your ideal air pressure. most 31" or taller tires can support light-truck weighted applications and jeeps are just too light, requiring only 1/2 of the max psi.
For instance:
2000 lbs at 50 psi max
2000 x 4 = 8000
My 4 cyl's jeep weight with add-ons: 3800 lbs
8000 / 3800 = 2.1
50/2.1 = 23.8 psi
It's best to set the front tires a little higher due to the engine weight.
25 front 23-24 rear