Tire pressure for BFG KO2's
- Thread starter tomdez
- Start date
stphnman20
Member
C-Rated 265 running at 40psi for me.
2010 Trail KDSS: C-load KO2's; I run 34 PSI front, 32 PSI rear. Did that for 65K on TA KO's, and still doing it on replacement TA KO2's. Live in a steeply hilled area with twisty roads. Perfect "wear pattern" and excellent ride quality. Lots of volcanic basalt based roads on my fly fishing sojourns and never had to mess with pressures for that. I just don't buy into running 40 PSI on C-load tire with our rigs. The extra 2 PSI up front helps with the cornering.
Gclark949
New member
I run my KO2s, stock size, C rating at 36 psi.
The correct answer is to look up the load inflation tables with reference to your GVW sticker info on the drivers door sill. Just calculate how much weight per axle (tire) and follow the instructions in below link. I really like the toyo 101 load inflation literature. They explain everything. I figured 35 psi for C-rated met the GVW.
https://www.toyotires.com/tires-101/tire-load-and-inflation-tables
The correct answer is to look up the load inflation tables with reference to your GVW sticker info on the drivers door sill. Just calculate how much weight per axle (tire) and follow the instructions in below link. I really like the toyo 101 load inflation literature. They explain everything. I figured 35 psi for C-rated met the GVW.
https://www.toyotires.com/tires-101/tire-load-and-inflation-tables
jkrueger2020
New member
So I've been wondering about this for a while. I have the 275 KO2 E rating. I've been running 38 psi, and I would describe my ride quality as harsh. Anything less than 38 and it drives like a slug.
Could the harsh ride be caused by my aftermarket rims (MB Vortex) somehow? Or am I too used to a car's suspension and need to readjust my expectations?
Could the harsh ride be caused by my aftermarket rims (MB Vortex) somehow? Or am I too used to a car's suspension and need to readjust my expectations?
I drove up to the mountains this past week and my tire pressure was almost 50psi in my 275 KO2 E rated tires once I was at elevation.
On-road it felt fine, but when I went off-road with that tire pressure on bumpy/rocky roads it was a little jarring.
38psi on regular roads should not result in a harsh ride.
jkrueger2020
New member
Thanks for the reply. Yes, 38 is my on road psi - not off road. Any ideas what could be the cause? I have the SR5 non KDSS with stock suspension. Could the wheels I bought have reduced the amount of air volume compared to stock wheels?
jkrueger2020
New member
Aren't E loads the only option when you plus size?
brian0128
New member
Factory Dunlop's load inflation table show 2425lbs at 32psi.
I called BFG and asked for the load inflation for stock size 265/70-17 Load Range C KO2's.
40psi 2075lbs
45psi 2255lbs
50psi 2470lbs
55psi 2595lbs
60psi 2760lbs.
Her recommended psi was 45psi and she wouldn't give me numbers any lower because she said it wouldn't support the weight of the vehicle safely.
Curb weight is 4750 and GVWR is 6300. Using 6300/4=1575lbs per tire. This tells me I could go as low as 38psi safely. I run 39 front and 38 rear and have even wear
I called BFG and asked for the load inflation for stock size 265/70-17 Load Range C KO2's.
40psi 2075lbs
45psi 2255lbs
50psi 2470lbs
55psi 2595lbs
60psi 2760lbs.
Her recommended psi was 45psi and she wouldn't give me numbers any lower because she said it wouldn't support the weight of the vehicle safely.
Curb weight is 4750 and GVWR is 6300. Using 6300/4=1575lbs per tire. This tells me I could go as low as 38psi safely. I run 39 front and 38 rear and have even wear
SirBarton
New member
I am running stock size KO2s and I concur with everyone who says around 40 is the sweet spot for on road..
Tire shops and Toyota service seemed to put them at 35 or 36. I notice improved mileage and smoother ride at 40-42psi. Now I tell them up front to keep them at 40 when they rotate or service them during dealer scheduled maintenance.
Tire shops and Toyota service seemed to put them at 35 or 36. I notice improved mileage and smoother ride at 40-42psi. Now I tell them up front to keep them at 40 when they rotate or service them during dealer scheduled maintenance.
e60ral
Banned
aren't the factory tires load index 113 at 32psi, so 2299lbs? EDIT: then divide by 1.1 since its a P-tire in a LT application so 2299/1.1 = need to match 2,090 lbs
i'm also confused about the ratings they gave you, i thought the C range KO2's were load index 109 which doesn't match what you posted.
also, keep in mind that the factory tire rating is not only based on GVWR, but also on fuel efficiency and handling characteristics like rollover prevention
day to day i run my c range KO2's at ~40psi, and inflate them more if i'm loaded up for a road trip. wear so far seems even
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It's hard to say without actually riding in it. It's possible you're more sensitive to the additional harshness of having an E rated tire and that there's nothing wrong.
It's possible the rims are contributing, but I don't think that's likely. I'd try to find someone else with a 5th gen and KO2s and see if their ride is the same.
brockvond
New member
I think the stock size bfgs in C are load rated 112 when not used in a dual wheel application. LT tires are rated to carry weight per inflation psi, without discount like a p-metric used in light truck or SUV applications. It looks per the BFG load chart that 40-41 psi is needed to carry the GVWR of the 4R.
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e60ral
Banned
so i checked, mine (stock size load range C) are definitely 109 load index and that definitely doesn't match what BFG posted. All the load ratings should be standard per ISO, right? so I'm not sure why BFG is providing a greater rating than the chart for a 109 load index in c load range
and that is a good reminder though when checking the capacity of the factory p-metric tires to compare you have to remember to reduce by a factor of 1.1. so to match the factory load index 113 p-tires at 32psi you need 2299lbs/1.1= 2,090 lbs per tire and for a c-range tire with a load index of 109 that is about 45psi
(i personally run lower pressure than 45psi if i'm not loaded)
03_4x4Runner
Senior Member
The wheels should have nothing to do with it unless they are much heavier than stock. I run the same 275 tire as you and there is no getting around the fact that they are stiff. Around my small town I run them at 32-33. Anymore and they are annoyingly harsh. When I am going to be on the highway on longer drives I run 36-38. When I get to my sons house in Tucson I go back to 32 because the roads are so rough it sounds like my 4runner is going to break from all the harhsness. 32 smooths it out. Off road 25 is the sweet spot for me for a smooth ride. Just experiment and see what works for you. I have also run 32 on the highway will no problem.
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brian0128
New member
The description for Load Range C is
Size: LT265/70R17
Sidewall Style: Raised White Letters
Load Range: C
Serv. Desc: 112/109S
112 is for single rear wheel and the 109 is for dual rear application.
That is correct from what the BFG rep told me.
brian0128
New member
I called BFG again and got the numbers again. The load Range C is 112 in single wheel application.
Factory Dunlop 113 Load Index
26psi 2194 (1994 after dividing by 1.1 for metric to LT conversion)
29psi 2315 (2104)
32psi 2425 (2204)
35psi 2535 (2304)
BFG is a 112 Load Index
35psi 1890lbs
40psi 2075lbs
45psi 2255lbs
50psi 2470lbs
55psi 2595lbs
60psi 2760lbs
Curb weight is 4750 and GVWR is 6300. Using 6300/4=1575lbs per tire. This tells me I could go as low as 35-38psi safely. I run 39 front and 38 rear and have even wear. On the local truck scale my 2015 4Runner weighs 5780 loaded with a full tank of gas, dog, wife, and camping supplies for 3 days.
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