Tire pressure for BFG KO2's

[Ventura_Hondo]

I'm running an E Rated 285/75/17 and driving around SF I typically see a range from 38-42 from temp changes. I'm in the heart of today's Tahoe storm and it dropped down to 36.

Yah that’s what I’m usually used to (4 psi) fluctuation 7psi just seems much. Yah stay dry I’m in SoCal so this rain is much needed for us.


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[MIKE969]

What I don't understand is this. The limited with 20" wheels comes with P245/60r20 @ 32 PSI. The load rating is 107 and at 32 PSI this equates to 1973 lbs, much lower than the other trims with 265/70r17.

Then subtract 10% to convert to an "LT" rating and that comes out to 1794 lbs.

Looking at the inflation table below for a LT265/70R17, 35 psi gives a load rating of 1890 lbs, which exceeds the Limited's stock tire load rating at the suggested inflation pressure.

https://www.toyotires.ca/sites/default/files/application_of_load_inflation_tables_20170203.pdf

Does the limited have a significantly lower payload rating than an SR5/TRD Off Road or TRD Pro?

If it does not, it means that the payload rating limitation does not come from the tires, it comes from the chassis/suspension/stability control tuning dynamics and you can safely run an LT 265/70R17 at 35 psi up to the 4Runner's maximum payload rating. Toyota therefore recommends 32 PSI on the 265/70r17 tires not for payload capacity but rather to maximize fuel economy.

Unless I'm completely lost

 

[Jivewalker]

What I don't understand is this. The limited with 20" wheels comes with P245/60r20 @ 32 PSI. The load rating is 107 and at 32 PSI this equates to 1973 lbs, much lower than the other trims with 265/70r17.

Then subtract 10% to convert to an "LT" rating and that comes out to 1794 lbs.

Looking at the inflation table below for a LT265/70R17, 35 psi gives a load rating of 1890 lbs, which exceeds the Limited's stock tire load rating at the suggested inflation pressure.

https://www.toyotires.ca/sites/default/files/application_of_load_inflation_tables_20170203.pdf

Does the limited have a significantly lower payload rating than an SR5/TRD Off Road or TRD Pro?

If it does not, it means that the payload rating limitation does not come from the tires, it comes from the chassis/suspension/stability control tuning dynamics and you can safely run an LT 265/70R17 at 35 psi up to the 4Runner's maximum payload rating. Toyota therefore recommends 32 PSI on the 265/70r17 tires not for payload capacity but rather to maximize fuel economy.

Unless I'm completely lost

You need to look at the load chart for the specific tire. My original P dunlops were rated at 2425lbs at 32psi, then derated to 2204lbs being on the light truck (4runner). Cross that over to the TAKO2's LT chart, and 44psi makes sense, 45psi would be 2255lbs.

 

[MIKE969]

You need to look at the load chart for the specific tire. My original P dunlops were rated at 2425lbs at 32psi, then derated to 2204lbs being on the light truck (4runner). Cross that over to the TAKO2's LT chart, and 44psi makes sense, 45psi would be 2255lbs.

Yes I understand that, the load chart for the oem limited 20” tire at 32 psi indicates a much lower load rating than the 265/70/17 equipped on the sr5/TRDOR/trdp.

What doesn’t make sense is that the owner of a limited t4r installing k02s will inflate them at 35 psi to match the OE 20” tire load rating, and the owner of an SR5/TRDOR/TRDP will inflate them at 44 psi to match the OE 17” tire load rating, yet as far as I know all t4rs have quite similar vehicle towing and payload capacities (the exact numbers are in my previous post).

It seems like the 265/70/17 oe tire was designed for larger vehicles with higher tire load rating requirements that far exceed those of the 4runner. Toyota would have kept the “overkill” inflation of 32 psi on the 17” tires for the sake of fuel economy, rather than out of necessity to achieve the tire’s specific load rating at that pressure.

At the end of the day, my point is that it appears that one could safely run LT265/70/17 k02s (or any other LT265/70/17) at 35 PSI as long as they don’t exceed the t4rs overall payload capacity, since the tire’s load rating exceeds the limited’s 20” tire load rating.

 

[Ben84]

Sorry for the n00b question but did any of those who got the 265/70/17 C rated had any problems?
Just got a new '21 Off Road with KDSS and I'm considering getting the 265, but I see that the load index is lower than the stock (112 vs 113) and wondered if this could cause any issue

 

[Johnrg]

Tested 35psi cold and hot peaked at 40.

I purchased stock size KO2's last week and 35 was suggested at the shop, so I made sure to accurately set them the next morning to 35. I remember seeing a post suggesting BFG stated 40psi to a question for a 4Runner using the c-rated tire. I have tended to make my adjustments based upon tire expansion when up to temp as a guide seeking 10-15% expansion/increase in pressure. There is also the temp variations and elevation but just seeking a balance of factors.

Today it was fogged in and 60 degrees on the coast at sea level. Drove 20 miles inland at 55-60 mph with temps approaching 80. Pressure after a dfew miles at speed was 38 on each wheel. Increased in temps to near 100 degrees on Figueroa Mt. and tires reach 39. A long downhill under braking tires reach 40 and at the very bottom, the rears at 41. In time and back at 55-60 mph in 80 degree temps and lower elevation tires settled at 39 and back on the 101 on the coast at highway speeds one dropped to 38.

So 35 seems to ride well and maybe loaded will bump them up but 35-37 seems a good start for me.

 

[TrailRunnin14]

I always ran mine at 36 psi. I tried 40 but it felt too rough for me. I put on 25k, set at 36, and they wore even.


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[5thToy]

I purchased stock size KO2's last week and 35 was suggested at the shop, so I made sure to accurately set them the next morning to 35. I remember seeing a post suggesting BFG stated 40psi to a question for a 4Runner using the c-rated tire. I have tended to make my adjustments based upon tire expansion when up to temp as a guide seeking 10-15% expansion/increase in pressure. There is also the temp variations and elevation but just seeking a balance of factors.

Today it was fogged in and 60 degrees on the coast at sea level. Drove 20 miles inland at 55-60 mph with temps approaching 80. Pressure after a dfew miles at speed was 38 on each wheel. Increased in temps to near 100 degrees on Figueroa Mt. and tires reach 39. A long downhill under braking tires reach 40 and at the very bottom, the rears at 41. In time and back at 55-60 mph in 80 degree temps and lower elevation tires settled at 39 and back on the 101 on the coast at highway speeds one dropped to 38.

So 35 seems to ride well and maybe loaded will bump them up but 35-37 seems a good start for me.

I am right there with you. I ignored the 40+ psi recommendations and employed the chalk test, keeping a close eye between rotations on inside/middle/outside tread wear. 35-36 PSI on 265 C KO2s with Al RCI skids and RSG sliders has maintained even tread wear.

 

[Jivewalker]

I've been running mine at 44psi cold per the load rating spec for my 2012 TE. Got 91,000 miles on first set and just put a second set on. Don't really consider it a rough ride, just a normal truck ride to me. I did all of the load calculations and the 44psi for my vehicle as stated by BFG is correct.

All that being said, airing down for wheeling and sand or driving unloaded can change where you land on psi. If you never load the vehicle or carry passengers it may be possible to subtract the payload weight and then do the calcs to come up with where it should be unloaded. I like to know that when road traveling fully loaded with 4 bikes on the back that my tires are at the correct psi. My .02

 

[2021nightshade4x4]

45 in my KO2 E load tires gave me similar ride to factory.

40 felt like I was in a DREAM, worth trying.

I wouldn’t not, however, go lower than 40 in an E tire.

If you get C’s, knock yourself out.


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[honda250xtitan]

45 in my KO2 E load tires gave me similar ride to factory.

40 felt like I was in a DREAM, worth trying.

I wouldn’t not, however, go lower than 40 in an E tire.

If you get C’s, knock yourself out.


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youre backwards...lmao. you think an e rated tire at less then 40 psi is a hazard on a small suv????


anyways


read this...
Tires and Wheels: How Do They Affect My Ride? – Carli Suspension, Inc.

 

[Glenn Goodlett]

I run E rated stock size at 32 psi. On a freezing morning they start at 28 psi.

 

[21_4runner]

I replaced the stock Bridgestone Duelers with the same size BF Goodrich KO2's on my 2017 Trail Premium. The Toyota recommended tire pressure for the Bridgestones was 32 psi. What pressure should I run in the KO2's? I asked BF Goodrich on their helpline, and they said 50 PSI, which seems ridiculously high.
Any help?

i have C rating 265/70/17 psi is 41-42. its pretty smooth to me. i had the bridgestone duelers and psi was 32-34.