PSI on tires - what do you run?

[RichardH]

Lots of things can affect gas mileage including temperature and even where the gas was purchased and different batches of gas from the same station but it is amazing sometimes how much a few pounds lower on the tires can suck the fuel mileage down. However, people will still argue and want to put very low inflation pressures due to the placards inside the door.

I don't give a whole lot of credit to the manufacturer's recommendation even with the tires that came from the factory on the vehicle but once you remove those particular tires then all recommendations really go out the window.

To me, it is much more logical and important to take the tire maker's recommendation then it is a manufacturer of the vehicle.
I just can't imagine a tire that has a rated maximum pressure of 51 pounds or greater printed on the sidewall being run and only 35 PSI.
For me, I even find that 35 PSI in a tire rated for 44 Max is too low. I much prefer 42-42 in those.

You still need to keep an eye on the mill because if you are running a few pounds higher than optimal , you might get better fuel mileage, but you will notice increase wear on the center of the tires so that means you are slightly over inflated.

Good points. For reference temps have been consistent with old mpg vs new, and I've had a full tank so old #'s/new #'s are with same gas, so the comparisons are as close as apples to apples as I can get.

But again, you make good points re: psi - mfg oem tires/stickers vs replacement tires. I already do check the tread wear with a homemade depth gauge - so far so good, and thanks for reminding me.

 

[TobyU]

Good points. For reference temps have been consistent with old mpg vs new, and I've had a full tank so old #'s/new #'s are with same gas, so the comparisons are as close as apples to apples as I can get.

But again, you make good points re: psi - mfg oem tires/stickers vs replacement tires. I already do check the tread wear with a homemade depth gauge - so far so good, and thanks for reminding me.

Sounds like you have eliminated most of the possible variables.
There is also the chalk method which gives you a fairly accurate idea of proper inflation with how the chalk wears off of your tires when you draw a heavy line across them but any small amount is really extrapolated over the course of thousands of miles so by keeping an eye on your tires you can kind of tell if they're wearing more on the edge or than the center.

 

[RichardH]

Sounds like you have eliminated most of the possible variables.
There is also the chalk method which gives you a fairly accurate idea of proper inflation with how the chalk wears off of your tires when you draw a heavy line across them but any small amount is really extrapolated over the course of thousands of miles so by keeping an eye on your tires you can kind of tell if they're wearing more on the edge or than the center.

Interesting. I have never heard of that but will try it. I thought weekly pressure checks and depth inspection is good, but I like the chalk method. One more way to check. I need to find some chalk.

Thanks!

 

[Aspen03]

I have the navigator at 40 in all corners right now. Its only had about 12mi put on it since the tires went on and hard to judge ride quality based in that. The LTX M/2 are the first tires I've had on a vehicle of this type rated at 51. It'll primarily be family hauler for running around locally so itll pretty well full most times. Easily 800lbs inside w 6 of us and the gear...car seats, stroller, etc.

I run the expedition at 37 but they are General Grabber HTS60 w a 44 max inflation. With just me cruising in it for work that seems to be the best compromise between stiffness and ride quality. At 35 the sidewalls are noticeably more soft. You wouldn't think 2psi would make the hig of a difference but it does.