Not Happy with Toyo 265/70/18 OEM Tires

[MikeUtah]

Have run KO2/K03 and other AT tires on several 4Runners. First experience with Toyo tires.
Comments:
1. ) Driving in my neighborhood (road is under construction) and ripped sidewall out of a tire. Very surprised tire could not handle rocks.
2.) Disappointed Toyo Open Country A/T III only have 13.4/32" tread depth when new.

Would like to replace with KO3 (265 70 18) but they are not available in C rating. Suggestions?

Thanks

Mike

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[fur_runner]

Well keep in mind the OE Open County is just a p-metric tire. The LT tires is an E-load tire w sidewall reinforcement

 

[MikeUtah]

Well keep in mind the OE Open County is just a p-metric tire. The LT tires is an E-load tire w sidewall reinforcement

As you pointed out, the 2025 4Runner Trailhunter OE Open Country A/T III tires are passenger tires, with a standard load (SL) rating.

Toyo does offer a few LT Open Country A/T III tires in a ‘C’ load rating. But not in 265/70R18. Many LT tires available in ‘E’ load rating. I have run many KO2/KO3 LT tires with a 'C' load rating.

 

[fur_runner]

I wouldn't be too scared of an E-rated tire (which is what the OE sized LT-version of the OC3 is) because while The Internet points out they ride worse, the sidewall reinforcement is a "rating" not a fact of life. As the ply rating goes up, so does the load range, and so does the pressure that load is measured at. People who get a much higher load rated tire and then run it at the same pressure as stock probably DO have a harsher ride.

Size	Load Index	24	27	30	33	36
P265/70R18	116	1982	2178	2392	2579	2668
LT265/70R18	124	2538	2788	3064	3296	3527
LT275/65R18	113	1824	2004	2205	2370	2535

Using the data here you can see that the OE load at set at 2579lbs per tire (which is why the pressure is set for 33psi.) Going up to an E rated 124 load index tire (the LT version of the OC3s or KO3s) raises the load rating so much higher that to maintain the load capacity you would want to drop down to 24psi, and if you did a C rated 113 load index tire you would need to go up to 36psi.

Personally, I think an E rated tire at 24psi gets you a lot more sidewall reinforcement, while also maintaining a decent ride. I totally get where ppl put them on and maintain the stock pressure and get beat up. To be clear, I have no dog in the fight for an OC3 or KO3, its just that all the OE sized rugged ATs are E rated and the same load range, they're all in the same boat

 

[MikeUtah]

I wouldn't be too scared of an E-rated tire (which is what the OE sized LT-version of the OC3 is) because while The Internet points out they ride worse, the sidewall reinforcement is a "rating" not a fact of life. As the ply rating goes up, so does the load range, and so does the pressure that load is measured at. People who get a much higher load rated tire and then run it at the same pressure as stock probably DO have a harsher ride.

Size	Load Index	24	27	30	33	36
P265/70R18	116	1982	2178	2392	2579	2668
LT265/70R18	124	2538	2788	3064	3296	3527
LT275/65R18	113	1824	2004	2205	2370	2535

Using the data here you can see that the OE load at set at 2579lbs per tire (which is why the pressure is set for 33psi.) Going up to an E rated 124 load index tire (the LT version of the OC3s or KO3s) raises the load rating so much higher that to maintain the load capacity you would want to drop down to 24psi, and if you did a C rated 113 load index tire you would need to go up to 36psi.

Personally, I think an E rated tire at 24psi gets you a lot more sidewall reinforcement, while also maintaining a decent ride. I totally get where ppl put them on and maintain the stock pressure and get beat up. To be clear, I have no dog in the fight for an OC3 or KO3, its just that all the OE sized rugged ATs are E rated and the same load range, they're all in the same boat

Thanks for the great comments and info! I also have no dog in the fight, just trying to get myself educated before buying replacement tires.

I have run LT KO2 ‘E’ rated tires before, at a reduced air pressure, but not down to sub 30 PSI. Any concern running 80 mph with such low air pressures? If I run low PSI, I would have to adjust the TPMS warning level, I think it is adjustable on the 2025 4Runner?

Since I live in the very snowy mountains, I REALLY like the addition tread depth on LT “E’ rated tires!

 

[fur_runner]

Its tricky. ETRTO has guidance that says for every 10% from the maximum pressure, you should reduce the speed rating 10%. So that would work out:

Tire	Rating	Speed	Max Pressure	Load Pressure	Reduction	Safe Speed
P265/70R18	T	118mph	44	33	25%	89mph
LT265/70R18	Q	99mph	80	24	70%	30mph
LT275/65R18	T	118mph	50	36	28%	85mph

So, ETRTO says maybe air those E loads up a bit...

Doing the math backwards, and saying what pressure would you need to be at to maintain the same effective safe speed as OEM (which as an aside is a little low to me) would be 64psi which seems unlikely that most ppl who run E loads on the highway actually run

If one were to slap some Q speed rated E loads on and put them at the OE 33psi, it would still only be safe to 47mph. I think thats a pretty common scenario, and I don't see tons of blow outs (yet!)

 

[MikeUtah]

Its tricky. ETRTO has guidance that says for every 10% from the maximum pressure, you should reduce the speed rating 10%. So that would work out:

Tire	Rating	Speed	Max Pressure	Load Pressure	Reduction	Safe Speed
P265/70R18	T	118mph	44	33	25%	89mph
LT265/70R18	Q	99mph	80	24	70%	30mph
LT275/65R18	T	118mph	50	36	28%	85mph

So, ETRTO says maybe air those E loads up a bit...

Doing the math backwards, and saying what pressure would you need to be at to maintain the same effective safe speed as OEM (which as an aside is a little low to me) would be 64psi which seems unlikely that most ppl who run E loads on the highway actually run

If one were to slap some Q speed rated E loads on and put them at the OE 33psi, it would still only be safe to 47mph. I think thats a pretty common scenario, and I don't see tons of blow outs (yet!)

Yep, I agree may folks are running ‘E’ at reduced PSI with no apparent problems.

A few observations:

• Wonder why the LT265/70R18 ‘E’ loading, are rated at ‘Q’ or 99 mph? Most other ‘E’ Open Country A/T III are ‘S’ or 112 mph.
• The P265/70R18 has a max load of 2756 (lbs.) whereas the LT275/65R18 113/110T, ‘C’ has a max load of 2535 (lbs.). I’m not sure I understand this.

Thanks for your time!

 

[fur_runner]

Yep, I agree may folks are running ‘E’ at reduced PSI with no apparent problems.

A few observations:

• Wonder why the LT265/70R18 ‘E’ loading, are rated at ‘Q’ or 99 mph? Most other ‘E’ Open Country A/T III are ‘S’ or 112 mph.
• The P265/70R18 has a max load of 2756 (lbs.) whereas the LT275/65R18 113/110T, ‘C’ has a max load of 2535 (lbs.). I’m not sure I understand this.

Thanks for your time!

Yeah, the C rated OC3 is a lower load rating than the P-metric OEM tire. I think that is something ppl who just go with "get an LT tire w a lower ply rating to maintain ride quality" way of thinking get caught out with.

The ply rating is an equivalent sidewall reinforcement, which doesn't mean the load rating is increased - in this case it goes down! And it's important to point out that all tires have their max load rating measured at max pressure. For p-metric tires thats usually 35psi, and for C/D/E rated its usually 50/65/80psi, which are all outside of the normal operation for most ppl

And I'm glad to help, I'm literally in the same boat flipping a coin on OC3s vs KO3s, so I'm on the same journey as you, just a couple steps ahead

 

[fur_runner]

Also, I made a math error on the safe pressures. For the Q speed rated OC3 you would need to be at 72psi to maintain the OE safe speed rating, and 64psi to maintain it with the KO3s since they start with a higher speed rating. Both are pretty extreme though

 

[MikeUtah]

Also, I made a math error on the safe pressures. For the Q speed rated OC3 you would need to be at 72psi to maintain the OE safe speed rating, and 64psi to maintain it with the KO3s since they start with a higher speed rating. Both are pretty extreme though

Definitely a coin toss between OC3s vs KO3s (E). Since I live in the mountains, the slightly higher rating (Tire Rack) for winter and wet conditions, I will probably go with the KO3. But the OC3 weigh a little less (6 pounds) and have a tiny bit deeper tread (0.3”).

Tire Rack comparison:
https://www.tirerack.com/tires/Comp...17&sortCode=null&rearSortCode=&tireIndex=null
Did not copy as a continuous link?

Best!

 

[Ramsfan611]

I have KO3’s, 265/70/18 on TRD pro wheels. Run at 35 PSI all day. No issues at all. Air’d down to 20 psi on beach, no issues.

 

[Fredot]

As you pointed out, the 2025 4Runner Trailhunter OE Open Country A/T III tires are passenger tires, with a standard load (SL) rating.

Toyo does offer a few LT Open Country A/T III tires in a ‘C’ load rating. But not in 265/70R18. Many LT tires available in ‘E’ load rating. I have run many KO2/KO3 LT tires with a 'C' load rating.

 

[tyrenurd]

As you pointed out, the 2025 4Runner Trailhunter OE Open Country A/T III tires are passenger tires, with a standard load (SL) rating.

Toyo does offer a few LT Open Country A/T III tires in a ‘C’ load rating. But not in 265/70R18. Many LT tires available in ‘E’ load rating. I have run many KO2/KO3 LT tires with a 'C' load rating.

Just to earmark this- the SKU 356310 is actually not the OEM SKU. The OEM Toyo AT3 only starts at 10/32", not 13/32. Kinda like what they did with the Falken AT3W on the Tundra TRD Pro. The OEM tire is also a totally different compound than the 356310 SKU- the factory installed Open Country is a 360 AA UTQG, and the one you have above is a 600AB. They perform and handle differently.

The OEM SKU is 310810.

Sorry, I saw this and wanted to make sure you have all the info to look at everything in the correct lens. A true Toyo Open Country handles totally different than the factory ones do.

 

[MikeUtah]

Just to earmark this- the SKU 356310 is actually not the OEM SKU. The OEM Toyo AT3 only starts at 10/32", not 13/32. Kinda like what they did with the Falken AT3W on the Tundra TRD Pro. The OEM tire is also a totally different compound than the 356310 SKU- the factory installed Open Country is a 360 AA UTQG, and the one you have above is a 600AB. They perform and handle differently.

The OEM SKU is 310810.

Sorry, I saw this and wanted to make sure you have all the info to look at everything in the correct lens. A true Toyo Open Country handles totally different than the factory ones do.

Thanks for the info! Had no idea there are two 'versions' of the 265 70R 18 SL Toyo AT 3. That explains my bewilderment when I replaced a OEM tire and the new tire had different tread depth!

 

[AZTrail]

BFGoodrich is scheduled to release in 2026 a KO3 265/70R18 load range D tire. Join me and others in requesting BFGoodrich to make a 265/70R18 load range C KO3.

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