PSI will be on the sidewall of the tire. If that can not be found, there is a sticker on the driver door jam that has a table for psi. If that is gone, then the owners manual (if it still was with the truck since it's used) would have it.

And in case, Nissan always has every owners manual for free on their website:
https://owners.nissanusa.com/conten...m/content/techpub/ManualsAndGuides/Frontier/2015/2015-Frontier-owner-manual.pdf

Edit: My apologies, I misread OP, this is backup and stock or just in case.

 

The PSI molded on the side of the tire is NOT the recommended pressure. Usually they list the MAXIMUM pressure and load the tire can take. The recommended pressure will vary by vehicle (how would the tire maker know what vehicle it’s going on) and be, as you stated, on a sticker and in the manual. As another poster suggested, the chalk test will help you determine the exact pressure you need for your particular vehicle, tires,and load.

 

For LT or MT tires, start at 42PSI and do an across the face tire-tread chalk test, three stripes roughly equally spaced around the tire's circumference. There are many YouTube videos explaining the procedure, but it's really quite simple, basically you are looking for the chalk or shoe polish to wear off evenly all the way across. Near the edges first, too low pressure, down the centre, too high. Adjust as necessary, then go drive it like you stole it.

 

Yeah... don't just guesstimate and add __-psi just because it's not a regular P-rated tire.

I agree with @RyanD1966 - if you don't have a tire manufacturer-recommended number to use, then the chalk test is the best way to go here.

 

If the placard gives a pressure for P tires, i.e P 265 75 R 16 and you are using LT tires, i.e LT 265 75 R 16, then you add about 15 psi to what is listed on the placard. otherwise you can overheat the tires due to excess sidewall flexing. In your case, about 50 psi should do it.

Edit: there is an organization who sets the standards that all tire manufacturers follow, but google wont tell me what it is. I have found it before but I don't have time to drill down through 200 or so pages to find sites that don't pay a fee to google for every hit. But there is a site that I did find that basically uses their charts although with a little less information.

LT-Metric Tire Load and Inflation Table

Tire load and inflation table for LT-Metric tire sizes with acceptable tire inflation pressures and corresponding load carrying capacities.

tirepressure.com

According to the P metric table, a P 265 75 R16 has a carrying capacity of 2601 pounds at 35 psi.

An LT 265 75 R16 has load capacities of:
35 psi - 1910 lbs
50 psi - 2470 lbs
55 psi - 2625 lbs

 

That chalk method is pretty neat. Reminds me of using string to align the wheels. Nifty!

 

What’s that tire pressure calculator website? I’ve seen it posted on the forum a time or two, but I don’t know the site. That would get ya close.

 

tirepressure.com link in my post above.

 

Many thanks for the practical input, everyone. I think I can dial in the right air pressure now, with your help. The tires don't have info on max PSI, and the Nissan sticker doesn't apply because these are knobby, bigger than stock tires, for mud & dirt. The Dick Cepek brand sold to Mickey Thompson (in 2012?) and neither web site is working now, though I've seen "Extreme Country" tires for sale at several other online sites at what seem to be good prices. Muchas gracias a todos!

 

If the tires are from before 2012, you should drive to the tire shop today and get new ones. 10 years is really long in the tooth for a tire.

 

Thanks, skramer, your concern got me to check the age of my tires. (I was wondering how they could look so "new"!) So I checked the DOT number: 1118, meaning they were made the 11th week of 2018. I was way wrong on when the mfr sold to Mickey Thompson. It was 2020. So my tires are still "youngish."

 

I bought my 2015 Frontier in 2021 and need to know the proper PSI for the tires that are on the truck. They're
Dick Cepek Extreme Country tires LT 265 75 R16. The company was bought by Mickey Thompson company, which I believe doesn't sell or manufacture these tires.

Thanks.

MAX Cold PSI is labeled on each tire man, if not the outside, check the inside. My Michelin motorcycle tires are only labeled on one side, for example.

Looks like you got some great replies already.

 

The PSI is 35. The tire manufacturer lost the max psi on the sidewall since it can be used on any vehicle. You should not run your truck at the max psi stated on the tire. The frontier is recommended at 35 as you know. 35 psi in any size tire is still 35 psi. Just because you changed sizes doesn’t mean you need to change your tire psi.

 

My Opinion- You shouldn't run the Max Cold PSI

Fact- but you definitely can run the max spec on the tire without any safety issues, that's the design specification and why it's written on the tire.

Other than the fact it'll ride overly rough, rofl, but it's definitely not unsafe. Just a little unbearable for driving your mom (lol)

10% under the max is where BFGoodrich said we should run tires designed for our work engines for maximum performance benefit on a year round average, which gives room for ambient temperature changes

Just really depends on tire manufacturer, sidewall stability, and what you are doing in that moment - grocery run? track? off-roading? driving grandma? hauling a load of mulch? towing a trailer?

If you put on oversized tires, the rubber in the sidewall acts as part of the suspension, so you may want to turn up the psi to your liking in that case. Even a half inch more sidewall is going to give you a more spongy feeling at the same psi if the construction of the tire is the same.

The manufacturer's label doesn't know the type of tires you have, but 35 is a common enough pressure to tell people who don't care to worry about all the other information. It gets you in the ballpark, but realize that's what it is, a ballpark figure that works with most tires.

Information is fun, isn't it?