Best tire pressure for mpg on 285s?

You could do duratracs or general grabber at2’s if you are looking for an at tire.... you will just have to look up the specific tire and its weights to determine. I run my e load 285/75/16 duratracs and love them 38 psi gas mileage pretty shanty though. 14-15 best around town. Looking to go 4.88s

 

Without upper control arms I'd say yes set the alignment to stock settings and maybe have them put the caster to the high side. That will help with tracking and any tire rubbing you may have

 

I don’t have a link but it’s so easy if you understand what you’re doing. Which is looking for even contact between tire tread and the ground.

Find an asphalt or cement surface in good condition.

Grab some chalk - I stole a fat stick of my kid’s pink, for added visibility

Start with your tires over inflated a bit so you don’t have to keep adding air in order to find the right psi

Rub the chalk on say a six inch or so cross section of your tread on all four tires

Drive fifty feet in straight line - no turns!

Inspect the chalk marks:

Even wear to the chalk and you’re done

Greater wear on the shoulders and less down the center = too low pressure

Greater wear in the center = too high pressure

Repeat as needed.

Simple.

 

Dunno if it's been mentioned before but remember to calculate the ratio increase when you do the math to get your mpg. On e-rated 285 I was seeing a very consistent 17.5mpg and after switching to these p-rated falkens, I jumped to about 19mpg. Mixed driving, 80mph to work (early am), stop and go to the house.

 

Y'all need to regear or keep your foot lighter. Hell I get 14-15 on 315/75/16 duratracs with a supercharger

 

I like them a lot so far. Good ride, pretty quiet, and relatively light weight. We’ll see how they are on the road when the rain gets here.

I haven’t really had them on any rocks yet though but I’m pretty confident in Cooper.

I like them enough to pick up another for a total of six, to keep them all in rotation.

I have the OME 2.5” heavy coils and leaf springs. Ride is nice and firm but not at all jarring.

 

I drive a good many miles per year, on Cooper STT PRO (mud tire) 285/75r16's. PSI DOES effect mileage to some extent. You won't "gain" a great deal, but the wrong pressure will "lose" mpg's in a big way. I've done chalk test, "butt dyno ride test", life span of tires visual test, etc.... Long story short, I've done my homework on these tires on my truck, under the driving conditions I experience.

A few observations; Chalk test can give mixed results. It isn't always the end all final way of determining psi's that some would lead you to believe. There is no "set it once and never change it" number either. I've found with these tires, there is a wide window of opportunity as far as high and low numbers where chalk testing can lead you. I've determined that 33/34 psi as a low point, and 40/42 as a high point will show "X marks the spot" results. What the chalk tells you now may not hold true after 10K miles, or 20K.... I've been able to get results on better mileage by staying in the 38 to 40 psi range. Tire wear can be improved by varying psi over the life of the tire. I've managed to wear out one set of STT PRO's (44K +) and I'm probably 1/2-way through second set. I measure tread depth on both edges and in middle at every rotation, and make adjustments accordingly. As I understand it, I'm getting very high mileage (wear) from these tires relative to results by others.

But speaking to gas mileage only, my best results are in the 38 to 40 psi range.

 

Buy a Prius you mallcrawler

 

Agreed. The chalk test will give a good contact patch across a fairly wide range of pressures. Unloaded, I’m at 30psi per door placard for ride quality, handling and wear. But I could add a few more psi and still have a good contact patch. I started at 38 psi and settled on 30 to meet the aforementioned criteria.

 

Lol

 

Plus, rim width, truck weight, tire brand, and 20 other "minor details" can have a cumulative effect.

 

Right but I think those will be accounted for in the chalk test.

 

In the case of my truck, weight varies with each passing day. I carry a lot of tools on certain days. On camping trips, load varies according to where we're going, time of the year, etc....My point being, things change. Gotta find a psi that accommodates a variety of conditions, or be willing to change psi frequently.

Today as an example, I have roughly 500lbs of cargo that WON'T be there tomorrow.

 

I run 36 in front and 34 in rear. After 56000 miles of wear the center is worn a little more than the edges. I average 17.80 MPG with 33's and a 4 inch lift. I will be getting new tires in the spring and going with the Nitto Ridge Grapplers from the Trail Grapplers. I should reclaim about another .5 MPG with the change.

 

Yea, I wouldn’t necessarily make any changes for short distance load increase, unless it was really heavy, and necessary to avoid a blow out. But for longer distances I would. I’m about air up a few psi this am bc I’m about to drive a few hours with with an extra load.