Tire pressure going from SL to Load Range E tire

I went from the stock 265/70R16 Goodyear Kevlar's to 285/75R16 Load Range E tires. I've always kind of wondered about what the correct tire pressure is. In my case, what tire pressure with Load Range E tires equals the same load carrying capacity of the stock tires?

When it comes to Load Range E tires, we know they are stiffer than the stock SL tires and this can impact the ride. We don't need to set our Load E tires to 80PSI to have 3,750lbs. capability on each corner (which is almost 3X the GVWR of the Tacoma). So, what do we do? Match the door panel at 30psi or set them at max capacity at 80psi? That's a big divide.

It has always been guys saying 'well I run 34 psi, I run 32 psi, 38 psi, 40 psi, etc.' which is empirical and is fine. Others use the chalk message which is equally fine and I have done that too.

I've always thought that there should be a load vs. psi chart per tire so we could all fine tune it. Turns out there is. There are industry standards that tire manufacturers adhere to for psi vs. load for all sorts of tires (P-metric, metric, flotation). The two main standards are from the TRA (Tire and Rim Association) and the ETRTO (European Tire and Rim Technical Organization). These two bodies are formed from industry and all of our tires confirm to one of their specifications for load vs. psi.

I confirmed that the Goodyear 265/70R16 OEM tire on my 2018 Tacoma Off Road conforms to the ISO Metric (ETRTO) load standard. The numbers match for the Standard Load 112. Further I confirmed that my Cooper Discoverer ATR3 XLT 285/75R16 Load E conforms to the TRA Light Truck Inflation Table chart.

I plotted both tables' data below. You can see the load vs. psi of the OEM Goodyear (blue) and the load vs. psi of the Cooper (orange). By plotting load vs. pressure, I found what the pressure 'should be' on paper relative to the specifications. Basically, to maintain the same load capability of the Goodyear set to 30psi (on door sticker) @ 2149lb, the corresponding Load E tire pressure is 35psi.

You may have already known this, it was informational to me and I like knowing the aftermarket tires are dialed to match the load capabilities of my Tacoma without overpressuring and making the ride too stiff.

 

I've always run 35 on E rated. Guess I'll keep running 35.

 

Same here. When I first picked my truck up, the dealer had the E rated KO2s aired up to 50 psi...thought I was going to die on the freeway ride home, every little bump in the freeway made the back end feel like it was going to jump sideways.

 

Says 50 psi right there on the side of the tire! - Dealer probably

 

Actually the KO2s say 80 max PSI on the sidewall, thank god they didn't put 80 in them lol

 

3d gen Tacomas have a load inflation weight of 2,149 lbs-2,172 lbs
265/70/16/112 @ 30 psi = 2,149 lbs
P265/65/17/110 @ 29 psi = 2,149 lbs
P245/75/16/109 @ 32 psi = 2,172 lbs

The vehicle manufacturer de-rates euro-metric and P-metric tires for use on trucks and SUVs.
If you switch to LT tires, the new load inflation weight is 2,149/1.1=1,954 lbs.
An LT285/75/16/E has a load inflation weight of 1,978 lbs @ 31 psi(extrapolated from 35-40 psi).

TOYO PDF
https://www.google.com/url?sa=t&sou...Vaw0zaHumL9xB01d0CRYFLPCS&cshid=1562890063059

NITTO PDF
https://www.nittotire.com/media/152964/TechBulletin_NTSD-12-011.pdf


https://www.tiresafety.com/en_us/choosing-tires/sizes-and-classifications/light-trucks-and-suvs


https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=195


https://www.moderntiredealer.com/article/311494/lt-or-p-metric-tires-for-light-trucksuv-applications


https://www.tirereview.com/tire-types-and-load-capacity/