Jreimnitz150

Mine are 8 ply (load range D) I haul my fishing boat, atv's, and snowmobiles around. Its all about proper inflation during towing. You can always go 10 ply (load range E) as well for a more stiff sidewall.

jplundma

Do I lose anything by going up in load rating? mpg?

Jreimnitz150

MPG in theory should not be affected by going up in rating. However, you will notice the difference when it comes to ride quality. E is more stiff. Some of us have range E on our trucks but thats most commonly for the 3/4 tons in my opinion. Do some research on the tire you choose though, and see what the tires are rated for weight wise. I attached the spec sheet for goodyear duratrac's in the size you have currently (265/70r17). The sheet shows two different load ranges of the same size tire. C and E. You can see that the max load is significantly different between the load ranges. Choose which is best for your application.