What psi should i run?

new to this thread but, when you guys are advocating running pressures of say 34 lbs per tire, are you generally advocating this for daily driving, city and highway? offroad is of course a whole different thing obviously. Also I am guessing that tire pressure depends upon the sidewall stiffness, etc etc.
Is it fair to say there is a "range that most tires fit into say 32-36 lbs, etc etc.
I have obviously been erroring in my calculations. I have been running more like 40 on my Goodyears Wranglers, thinking that I will get better mileage out of them.

 

Yes, most recommendations are for daily drivers.

Different sizes and/or load index require different PSI to achieve the same inflated load capacity. The PSI could range from 28 PSI for a 265/70/17/115 SL to 43 PSI for a LT/235/85/16.

I'm going to assume you're talking about the OEM Goodyear tire @ 40 PSI...
What you're essentially doing is making less contact patch. Everyone makes a big deal about the latitudinal patch, but, you actually lose a lot more on the longitudinal patch.
FWIW, inflated load capacity for your tire maxes out at 36 PSI. Any inflation beyond this point is done to attain the speed rating.

 

still not sure I understand the relationship or the ideal sweet spot for load rating vs speed rating vs noise vs longevity etc.This appears to be a complicated subject,
car tire vs truck tire, vs?
P rating, A/T, LT, etc etc.
Must be something that is ideal for the way most of us use our trucks.
I am going to guess the most common use of our trucks is a daily driver, limited off-road, limited weather issues, and a mix of highway and city driving.

 

Can I suggest checking inside door frame for PSI recommendations and not without saying do a chalk test to confirm...I did; it confirmed 30psi
Good Luck

 

I DO PLAN ON TRYING TO CHALK THING YES.
However I didn't think the factory recommendation would be of much value since I am completely changing tire size and type

 

What size and load rating?

 

285 70 17.
This is the size I've decided upon but have not bought the tires yet pending a decision over what specs to buy

 

The psi on the door attains a 2,149 lb inflated load rating from P and euro metric tires; or 1,954 lbs from LTs.

It looks like 285/70/17s come in load ratings of 117SL for P-metric, 116-117SL for euro-metric and 116-121 for LT-metric.


2,149 lbs for a P-metric is way off the chart...I'd chalk test.





For euro metric...
27 psi for 116 load rating
26 psi for a 117 load rating






You could extrapolate a value of 42 lbs/1 psi between the values given for 35-40 psi.
This would give you 32 psi and 1,979 lbs of inflated load rating.

 

For S and T rated tires, the adjusted psi speed rating doesn't come into play until you reach an excess of 100 mph.
https://m.tirerack.com/tires/tiretech/techpage.jsp?techid=72

 

All depends on what your doing.. What kind of tires/ what their rated at.

Stock tires. Id say 38-40 front 36-38 rear for regular street use. Just my opinion.

But every tires different.

 

I run 35 psi all around.

 

I’m going to do the chalk thing, but curious if anyone has an opinion (haha, it’s TW) on running 265/75/16 on an 8in wide rim. Currently they’re at 34psi but they spread so much more than when they were on the 7in wheel they look kinda flat-ish! Thanks much

 

What's the load index?

 

Thanks. Pardon my ignorance. Should I consult the tire for that, or is this something to do with the weight of my vehicle, loaded, or both?

 

Is it an LT?

If not, what exactly does the sidewall say?
Examples:
265/75/16/116
P265/75/16/114

 

LT265/75/16 123/120R Load Range E
Method 701 16x8

Thanks man!

 

37 psi

 

Thanks. That's the cold pressure you recommend? It gets up to 37 when running down the highway.

 

Yes; cold.

 

Sorry to bother... what's the recommendation when fully loaded for adventure? Also since I have you, what would you recommend airing down to after driving on highway for several hours (because, California) when we get to trails?

Curious about 37psi, not that I doubt you and you seem really knowledgeable - the tables above don't seem to even go that high. What's the science behind it? Thanks much! Owe you a beer in the brave new world haha. Sis lives out your way.