Tire pressure question

MNRon wrote:
I wouldn't get too carried away trying to find an "optimum" pressure less than the max rated one. Not sure where the 'pressure formula' quoted comes from, never seen it before and don't believe it's that simple (it would suggest a 6psi inflation if only carrying 250lbs ??). They are accurate that full inflation pressure (65psi) will do best to protect the tire, with trade offs of poorer ride quality and potentially worse wear in middle of tread. Given that you won't wear out tread on a trailer before needing to replace because of time (4/5yrs), the tread wear argument is moot. On a TT I view the minor ride quality benefit as a poor benefit to trade against everyone's concern of tire failure.

Don't overthink it, run what the tire manufacturer recommends as max capacity rating.

Why is running proper pressure overthinking? I don't know of any tire manufacturer that reccommends max pressure for any load.

The formula is a relativly well known one for determining pressure. Sure if you had 250lbs on a tire it may only need 6 psi; however, most tires have a minimum pressure (15-20 for ST, 20-25 for P or LT tires, 70-80 for LRF+). That forumla is a quick reference guide and actually puts a little more air in the tires than most inflation charts do for loads less than max. You can see in the link below that only 45 is needed per the chart, but if you don't have access to the chart the simple formula is plenty of air. The only caveat is extended high speed running, where an additioal 10 psi is reccommended by many tire manufactures. Goodyear even lets you run up to 10 over the sidewall pressure on the Marathon for speeds of 66-75.

It really isn't complicated to run the proper pressure. The only true benefit to running max pressure for any load is the ability to be lazy with pressure adjustments. But for most people 5-10 psi above chart gives the wiggle room for load changes and speed variances, as well as a little cooler running tire while not compormising traction, tread life, handling, and increasing road hazard susceptibility.

Not sure how often you tow with your trailer but wearing trailer tires out in 4-5 years is easy if you camp enough. Heck in 3 season I did a 6 tire rotation on my tandem axle trailer and 4 of the 6 are worn out.

http://toyotires.com/sites/default/files/page-files/LoadInflation_Table_P-LT_102913.pdf

http://www.goodyearrvtires.com/pdfs/rv_inflation.pdf