Range E tire pressure

That what we do when we off road

 

This^

Chalk test is useless and running E rated tires at lower PSI reduces the load carrying capacity and will actually wear the tires faster (the plies not the tread) due to heat build up. Yes the E rated tire is tough for off road driving, but it comes with the cost of high pressures and a jarring ride on road.

 

Unless you added weight to the vehicle, heavy bumpers, Roof tent, winch etc. You shouldn't go too much above stock pressure. For example I have a 96 land cruiser with front/rear heavy bumpers, heavy rock sliders, drawer system, sleeper platform, compressor and tank and I have Cooper Stt Pro's and inflate to 44 PSI. So when you add more weight the pressures should be adjusted accordingly.

 

These people are doing it on the road at 40psi. Ill take my more comfy ride at around 32

 

Yeah agreed 40 psi

 

https://www.tacomaworld.com/threads/what-psi-should-i-run.51690/page-15

 

35 front 33 rear on road. Towing 35 front 40 rear. Off road 18 all around.

 

Thanks for all the valuable tips guys. My bed is always filled up with camping stuff and/or scuba tanks, I have a bed rack and occasionally the RTT. I have them at 43 right now and yes the right is a little harder than it was, but I don't find it uncomfortable at all, although that is always subjective.

 

Okay, Fred flinstone

 

Running 265 /70-16 Toyo Open Country mud terrains at 28psi

 

Raising this thread from the dead. If your E rated tires are too harsh, lower the pressure. Went from 42 to 35 on my Geolandar X-AT 285-70/r17 today and it's night and day and I'm not usually the type that can tell a difference with tire pressures. I found a youtube video discussing this that made a lot of sense, the video is here: https://www.youtube.com/watch?v=TKOJK_tss7o

The video goes in depth with this but pretty much what you want to do is go to and put the OEM size and tire pressure from the door placard and then the specs of your new tires. Mine said to go to 35psi and wow it really is a lot nicer now. I think I will fine tune this with the chalk test eventually but pretty happy with this discovery at the moment. Lowering the pressure even cured the steering wheel vibes I had at 40mph. We will see about mileage, I'm at about 13 right now lol

 

Actually, you could probably go down to about 32 psi...
That calculator and the charts it's based off of, have a 'minimum' inflation of 35 psi.
You can fine tune it by extrapolating a load value(pounds) per psi based on the load values given between 35 and 40 psi. I wouldn't go below 30 psi using this method, though.

I say "probably" because I'm basing it off 3rd gen info...
If you know what your oem tire specs(size, p-metric vs euro-metric and load rating) and the door placard psi, I could give a more accurate answer.

 

The amount of people offended over someone else blowing more or less gas into their truck balloons is hilarious.

 

Stock size is P245/75r16 at 30 psi. Not sure what the original load rating is, probably around 110, whatever the third gen SR5 has is more than likely the same. Let me know. I might drop a few more PSI, didn't know I could run these so close to the stock recommendation. I'm still really interested in doing a chalk test though. I went through a small puddle coming into the driveway last night when it was at 42 psi and just from the water tire print you could tell it was over inflated which is what sent me down this rabbit hole in the first place.

 

Okay...

For a 2012, in that size, it was a 109 load rating.

A P245/75/16/109; @ 30 psi, gives a load value of 2,105 lbs. If it was a euro-metric 245/75/16/109, @ 30 psi, that gives a load value of 1,973 lbs.
Folks tend to conflate P-metric and euro-metric, or make no distinction. I just wanted to show the difference; and it is significant. If one doesn't enter the correct info in a calculator like you used, the answer will be incorrect.
I'm pretty sure yours came with a P-metric, so we will calculate from there.

When LTs are used on a truck or SUV, they are not de-reated like P-metric and euro-metric tires. So, LTs only require a psi to get a load value of 2,105÷1.1=1,913 lbs.

Here's the chart for a LT285/70/17...


@ 35 psi you have a load value of 2,105 lbs.
@40 psi you have a load value of 2,315 lbs.
So from that...
5 psi=210 lbs or 1psi=42 lbs

@ 31 psi you would be at 2,105-(42x4)=1,937 lbs load value.

 

Thank you so much for taking the time to write this up. I'll read it over and see where I want to go with it. Probably drop a few psi honestly but yeah thanks for giving me what I need to make an informed decision.

 

Here's a pdf link to Toyo's load inflation guide...
It'll explain the how and why of all that stuff I posted...and the p-metric and euro-metric charts I omitted.
https://www.google.com/url?sa=t&sou...4QFnoECB4QAQ&usg=AOvVaw0zaHumL9xB01d0CRYFLPCS

 

I am just seeing this. For my OEM 265/70/18 metric tires in standard load, I am rated for 2,153 pounds per tire at 30 PSI. To get to the closest equivalent in my brand new LT275/70/18s, the calculator says to go to 38 PSI, which can handle 2,190 pounds per tire (8,760 pounds for the whole truck). Given the GVWR of my truck is 6,835 pounds, I think that's overkill and the ride is crap at 38 PSI. I want to go down to 33 or so, as the ride is way better down there, but I am nervous to do so since none of the tables go below 35 PSI. If I extrapolate (not sure if you can), 33 PSI gets me to 1,990 pounds or 7,960 pounds for the truck, which is a full 1,125 pounds MORE than GVWR. Is there any reason I cannot go down to 33 PSI? Is there some safety issue with LT tires under 35? Like sidewall deflection or overheating? Or is 33 PSI sort of within the margin of error?

 

I've been running 30-32 this whole time based off splitbolt's recommendation. Seems legit, haven't had any issues just rides smoother. I put more air in if I'm going to tow something and take air out if I'm going offroad. Just send it, its not that consequential.

 

Seems like good advice.