Tire pressure

LOL man the OP is just gonna love this thread when he reads it. Taking bets on whether he posts again?

My apologies.

 

What else is TW for? lol

 

Ya it's 2am and I just got off a flight to bean town. Might explain my crankiness.

 

Or maybe it's that ridiculously stiff ride you took from the plane to your house

 

I have that soft tuned OR suspension working overtime!

I need to jump off. I'm sure I'll have a bunch of posts to wake up to tomorrow about this lol.

 

Not everyone has 275 70 18s.
These hold less volume, therefore more pressure is necessary than a tire with less volume; to obtain the same load rating.
PSI is a means to an end; not the be all, end all.

 

18s? You must be new here....

 

False

 

hey all! side question re: TPMS... so I've never really monitored my TPMS but lately I have and the numbers have been jumping around. Is this normal? Or should it be consistent and stick to a certain number? It ranges from 35 to 39. Thanks!

 

Your stock tire recommendation has a requirement of 2,149 lbs P/ISO metric; or, 1,954 lbs LT metric.
Your new LT tire size attains this at 33 psi.

 

I am able to calculate a pressure-range for you, in wich the tires dont overheat, and comfort and gripp is still acceptable.

For this you "only "need to give me for the situation, 100% acurate next.
1 weiht on seperate tires/tirepair, speed you wont go over for even a minute.
From tires next: 1: Maximum load or loadindex, 2: kind of tire to determine the AT-pressure, and 3: speedcode of tire.

Ofcource this 100% acuracy is never possible, so in the end the pressure calculated with a maximum reserve, can be by the inacuracy ( also in pressure device) end up to be yust enaugh to prefent overheating tires at the speed you drive.

But hovered over the 20 posts here, and some remarks.
Indeed a E-load tire ( AT 80 psi) needs for the same load ( and speed) , a higher pressure then the standard load P-tire ( AT 35 psi), but estimate it myself not to be 50 psi if P-tire needs 30 psi, but havent checked it so can be proven wrong.

And even for a normal car the pressure is given for GAWR's so assumed fully loaded, but with only driver and a little load, the pressure can be lower savely.

Give data neede as acurate as you can( so instead of seperate weighed weelloads , axleloads or GAWR( gross axle weight rating) and this "pigheaded Dutch selfdeclared tirepressure-specialist"will calculate it for you.
Greatings from Holland ( Europe)
Peter

 

I upgraded to BFG K02 e-rated 265/70R16 on my OR DCSB. Door sticker indicates 30PSI for OEM P265/70R16. Per the load inflation table linked below:

PSI 26 29 32 35
P265/70R16 2105 2216 2326 2403

Difference between 29 PSI & 32 PSI isn't that much, roughly 36 lbs per PSI, and puts 30 PSI at roughly 2250 lbs. That works out to 2045 lbs LT if I converted correctly.

PSI 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | 75 | 80
LT265/70R16 Single 1820 | 2000 | 2170 | 2335 (C) 110 | 2500 | 2655 | 2835 (D) 117 | 2955 | 3105 | 3195 (E) 121

It seems that it's roughly an additional 34 lbs per PSI between 40 and 45 PSI on the LT tire. 41 PSI (2034 lbs) would seem to roughly equate to the equivalent of the OEM load rating.

That being said, when I asked BFG they said to go 50 PSI both on road and off.

https://toyotires-1524598101.netdna...ication_of_load_inflation_tables_20170203.pdf

 

It's not a P-metric; it's an ISO- metric 265 70 16 with a load index of 112.
2,149 lbs @ 30 PSI...

The Sport tire is a P-metric 265 65 17 110SL with a recommendation of 29 PSI(2,149 lbs).

The SR has a P-metric 245 75 16 108SL with a recommendation of 32 PSI(2,172 lbs).

 

The lists of toyo are made with the formula America used for P-tires up to H/W division of 50% up to 2006.
After 2006 the TRA stept over to the calculation of European ETRTO, and this calculation is used since decades in Europe for all kind of tires , up to trucktires even.

This wrong formula leads to way to high loadcapacity.s for the the lower pressures, and this is also the reason why America stopped at a pressure of 26 psi , while Europe went as low as 1.5 bar/21.5psi.
If I check the calculation it gives not exact the values given in list above for P tire , but I think there has been some conversion and double roundings that courced that.
I placed in red below the values for the 265/70R16 calculated with the European formula( wich America stepped over to as late as 2006, saying it was for globaly having the same system).

The maximum load is calculated by the tiremaker for 160km/99m/h, and for higher speed the 35 psi AT-pressure has to be highened up with a system depending on speedcode.

The list for the LT tire with 80 psi , is still made with the old formula for LT , wich was a bit better then that for P-tires, but still gives higher loadcapacity's then the European calculation. Also in European lists the different loadranges are not placed in one list, but for instance C-load is made a seperate list for then D-load.

I made pressure/loadcapacity-lists with my own formula wich is even saver then the European calculation .
Are PDF's and can be found in next submap on my public map of one-drive that belongs to my hotmail.com adres with same username as in this forum (so jadatis). The USA map is filled , but the european map only few PDF's.
So beter use my lists , because they are save to laws of nature , wich are the same all over the world , also for tires.

https://onedrive.live.com/?id=A526E0EEE092E6DC!904&cid=A526E0EEE092E6DC

 

Quick question related to PSI...
What should I run my 6 ply 265 70 17 BFG KO2s at?

I don't haul anything normally just me and a single passenger.

 

@ JM.Taco
To less information to calculate it for you.
But I googled your sises and found Loadindex 112R wich stands for maximum load 1120kg/2469 ( 2470) lbs.

Speedcode given was R wich stands for max speed for tire = 170km/106m/h but best is to go from 160km/99m/h for wich that maximum load is calculated( Not an issue , who drives over 99m/h).

The 6PR( plyrated) is the European system and stands for AT 3.8 bar/55 psi for wich the maximum load is calculated.
Mayby you even find LRC or C-load on the sidewall , but this is AT 50psi/3.4 bar, and has given ( and still does) many conversion problems of to low pressure advice.
Other loadranges/plyratings are aproximately the same AT-pressures, though 8PR/D-load mostly 65 psi but also 69/70 psi used , and a single 4.25bar/62 psi , E-load/10PR AT 80 psi/5.5 bar , but also 5.25 bar/77psi seen . What counts is what is written on sidewall, so "maximum load Single 2470lbs AT 55psi( cold)" in this case. but be ware of European Tyres that are set on the American market and so give for instance C-load , sometimes they are conversed to 50 psi , and it would give on sidewall "maximum load single 2470 lbs AT 50 psi ( cold) "wich is wrong and leads to to low pressure-advice( and tire-failure, and the missery it can cource).

Also found 10PR tires in same sise with 121S , so loadindex 121 and max speed 180km/112m/h.

So knowing all this you can follow the link of my former post to get PDF's of pressure/loadcapacity lists.
Once you determined the loads on seperate tires , or axles , You can search back the needed pressure for that for up to 99m/h.

I can help you with that determining the loads , for that find GAWR's( gross Axle Weight Ratings) , GVWR( G Vehicle WR, Empty weight, and the way you load it ( so 2 persons in the front and a little load. Configuration of car is most likely front 1 axle/2 tires on it( havent seen else) and rear also 1 axle/2 tires on it, but can be Dual load so 4 tires on it.
Also give maximum speed you drive and wont go over for even a minute.
Best would be to weigh the car per wheel in the loading you use, but above data can make a rough estimation, wich you can compensate by using a adding of enaugh resserve to the loads.

But the pressure advices on car are given for the original ( OEM) tires and for GAWR's filled in in the formula ( sometimes the old American), and mostly up to maximum technical car speed.
So for your use it can be lower savely, and mostly front higher pressure then rear. Carmakers advice is mostly Rear higher then front.

Sorry I gave a slow answer to your quick question.

 

Fwiw I changed to general grabber at2's 245/75-16 load range e tires on my 17' dcsb or, stock suspension, I run them at about 38 psi cold, the ride still seems pretty soft.

 

I just put on 265/70/R17 BFG KO2s C Rated on my 2017 DCSB and was battling over what PSI to use. When I emailed BFG all my details, they said I should be running 45 PSI on front and back. I've seen other TW users post similar responses from BFG. Anything over 40 still seems high to me but wouldn't the tire manufacturer know best? IDK.

 

check again dude.
The oem tires are LTs just 6 ply.

and manufacture (toyota) recommends 30psi.
I run 32psi for no load. found its been best so far for the duratracs in C rated.


at 50PSI the ride would be terrible.
Are you one of those people that would look at the side of a tire and inflate to that PSI?
because that PSI is what the tire can handle, not what you have to run.

 

no they know best what their tires can handle.
NOT what the specific truck needs.

Given you're running a C rated you can basically follow what the sticker in the door says.

When my tires were installed I told the shop 32 psi and them being dumb cunts (they did more than just screw up PSI, also destroyed my lug key) filled to 45 like the duratracs said.
Ride was fucking terrible. Felt every little bump.

Tire manufacturer rating is simply what the tire can take under full load capacity. And when you get closer to that load capacity you should be at that PSI, but the tacomas are so light you don't need to be that high.

a 112 load index (c rated) is good for around 2200lbs PER TIRE. Your truck is no where close to putting that much weight per tire. your truck is only what 3500lbs? spread over four wheels. Maybe 4200 with passenger and mild load?