P285/70R17 Toyo ATII on Rock Warriors. Smart? (1 Viewer)

[bloc]

Hello all,

Finally acquired some Rock Warriors and am now considering tires for them. It's no secret here I don't like the ride quality of my LT285/65R18 -E KO2s, and am convinced a large part of that is the 42psi cold pressure required for them. I'm sure the 57lb weight doesn't help, 40lb for a stock "road" tire.

Also.. my trips are generally from central texas all the way out to southwest colorado, utah, arizona for relatively mild wheeling & camping. Gravel roads in Utah, passes around silverton/ouray are typical use-case. No crawling. As little mud as possible. I can't see adding a lift at this point as I really enjoy the driving dynamics of my rig as-is, and having rolled one rig (my 80) 1000 miles from home am pretty intent on avoiding that fate again. If I do lift it, I'd go to LTs.

Anyway.. the P285/70R17 Toyo Open Country ATII is 46lb, 1.6/32 less tread depth, and needs only 27psi to meet the 200 load-rating requirements. Rock Warrior low wheel weight might make this similar to stock. Being a P-metric my hope is I can recover some freeway mileage as well. The 18mpg I was getting on stock tires quickly dropped to 15 at the same speed on my 285/65s. Not sure how much of this is tire diameter, my 10mm strut spacers in front, or the e-rated LT-metric tire construction.

Am I making a big mistake considering this tire? Are the sidewalls going to be made of tissue paper? Is the 41 @gaijin or 46 (toyota) psi requirement for LT-metric tires on the same wheels needed to maintain stability and road-manners due to the larger sidewall? (as well as the load rating)

Give me your opinions..

_Bloc

 

[Borstar1]

I had the same size falken atw3 on my rock warriors, p rated for several years. No flats or other issues on south Texas ranch roads. Ride was much better than the previous e rated tires as well.

 

[bloc]

I had the same size falken atw3 on my rock warriors, p rated for several years. No flats or other issues on south Texas ranch roads. Ride was much better than the previous e rated tires as well.

What other mods did you have at the time? Suspension/rack? Any experience with fuel efficiency?

 

[gaijin]

Hello all,

Finally acquired some Rock Warriors and am now considering tires for them. It's no secret here I don't like the ride quality of my LT285/65R18 -E KO2s, and am convinced a large part of that is the 42psi cold pressure required for them. I'm sure the 57lb weight doesn't help, 40lb for a stock "road" tire.

Also.. my trips are generally from central texas all the way out to southwest colorado, utah, arizona for relatively mild wheeling & camping. Gravel roads in Utah, passes around silverton/ouray are typical use-case. No crawling. As little mud as possible. I can't see adding a lift at this point as I really enjoy the driving dynamics of my rig as-is, and having rolled one rig (my 80) 1000 miles from home am pretty intent on avoiding that fate again. If I do lift it, I'd go to LTs.

Anyway.. the P285/70R17 Toyo Open Country ATII is 46lb, 1.6/32 less tread depth, and needs only 27psi to meet the 200 load-rating requirements. Rock Warrior low wheel weight might make this similar to stock. Being a P-metric my hope is I can recover some freeway mileage as well. The 18mpg I was getting on stock tires quickly dropped to 15 at the same speed on my 285/65s. Not sure how much of this is tire diameter, my 10mm strut spacers in front, or the e-rated LT-metric tire construction.

Am I making a big mistake considering this tire? Are the sidewalls going to be made of tissue paper? Is the 41 @gaijin or 46 (toyota) psi requirement for LT-metric tires on the same wheels needed to maintain stability and road-manners due to the larger sidewall? (as well as the load rating)

Give me your opinions..

_Bloc

Let's start with the easy one - LT285/70R17's. My Recommended Cold Tire Inflation Pressure (RCTIP) for these on the LC200 is and always has been 40psi F/R. Toyota's original RCTIP was also 40psi F/R - see page 5 of this Toyota publication: Toyota 17" TRD Alloy Wheel Instructions. The 40psi is required to achieve the required design Load Limit of 2286 pounds for LT-Metric tires. In response to a FMVSS (Federal Motor Vehicle Safety Standard) that limits the minimum inflation pressure for all tires this size to 35psi, Toyota raised the RCTIP to 46psi so that even when the TPMS triggered at 25% below RCTIP it would still be at 35psi (rounded up from 34.5psi actual). This was nothing more than a CYA move on Toyota's part, not driven by any performance requirement deficiency of the tire when used at the RCTIP of 40psi. 40psi is required to operate this tire safely on road.

A concept that may be new to some is the characteristic of tire performance known as Tire Spring Rate (TSR). TSR is primarily driven by tire pressure - lower pressure = lower TSR, higher pressure = higher TSR. The lower the TSR, the more "comfy" or soft the "ride" of the tire is perceived to be. So, in most cases, a P-Metric tire will be perceived as providing a softer ride than an LT-Metric tire because the P-Metric tire has a lower RCTIP. In your specific case presented here, the P285/70R17 tires @ 27psi will provide you with a softer perceived ride than your current LT285/65R18 tires @ 42psi.

The elephant in the room for all these tire discussions is the law of physics. There is no getting around the fact that compared to a stock P285/60R18 tire; ANY tire that is larger in diameter, heavier, or has more rolling resistance (i.e. more aggressive tread) will yield:

- Slower acceleration
- Longer braking distance
- Worse gas mileage
- Poorer performance during aggressive maneuvers

These are the trade-offs we must consciously decide to make for better offroad performance and/or increased durability.

Your choice of a P285/70R17 tire @ 27psi will give you a more comfortable ride, but will still result (perhaps to a lesser degree than an LT-Metric tire) in all the trade-offs mentioned above - plus they will be less durable (resistant to puncture, etc.).

I can't tell you what is more important to you - you have to make that decision. But I can leave you with one word of caution: The P285/70R17 Toyo's you are looking at are an SL (Standard Load) tire. Usually, P-Metric tires for the LC200 are XL (Extra Load) tires. The SL tire will be more susceptible to failure under any dynamic load conditions like hitting a pothole, running over a curb, etc.

Make sense?

HTH

 

[RET2]

Thanks for the info, very informative.

 

[chilibit]

I run the P285/70R17 Toyo Open Country ATII at 34 PSI on the 17" RW wheels. Chalking and temperatures indicate to me that they are very happy at that pressure given my usage. Allowing for circumference differences the ATII is down slightly on MPG vs the OEM tire at 18" and that might reflect the tread pattern or construction or rubber compound. Hard to say. I am running Blizzacks on 18" right now and they are softer. As you would expect for lots of reasons. I occasionally tow a race trailer with the ATII but it is very aerodynamic and the whole rig with the car aboard is under 4000lbs. Tire temperatures on the tires rear seem to ignore the trailer which is only 450lbs at the hitch. If I only ran one set of wheels, or hauled heavier, or routinely visited sharp rock I would likely go with LT rated tire.

 

[Yossarian]

Nitto's very popular Ridge Grappler is also available in a P285/70R17, but not in an "XL". I've been meaning to get clarification on what exactly does the XL bring to the table from Nitto.

Ridge Grappler | Hybrid Terrain Light Truck Tire | Nitto Tire

The Ridge Grappler features a revolutionary dynamic hybrid tread pattern and provides a quiet and comfortable with off-road performance capabilities.

www.nittotire.com

For a non-built LC, i.e. no bumpers, winch, kitchen sink, shouldn't a standard P tire be sufficient over an LT? I would generally say yes for most users needs, but those who have placed additional demands on the tire may/do need the LT.

As a anecdotal data point, a completely stock LC on street tires did way more than just gravel roads in Breckenridge 2017.

 

[speyrod]

Bloc, I am looking for RW's now to replace my stock 20's and your concerns are similar to mine. I use my LX mainly as transport to hunting and fishing places. Things I don't wanted, a puncture while in the outback, decreased mpg, and significant change in handling. I am waffling between XL's and E but won't even look at P's I don't want to loose a the time changing a flat might take when loaded with all my crap. Everything is a trade off, that said every year I see trucks fixing flats on rough forest service roads due to speed and s***ty OEM tires.

Your 80 was my inspiration until a wind storm snapped a tree and totaled it. Funded my LX but still miss my 80 and she would have had an LS by now.

If I can't find RW's will get some Tundra 18" if I can find some ( hope with reasonable rubber) to give it a try and see how I like before fully investing.

 

[gaijin]

Nitto's very popular Ridge Grappler is also available in a P285/70R17, but not in an "XL". I've been meaning to get clarification on what exactly does the XL bring to the table from Nitto.

Ridge Grappler | Hybrid Terrain Light Truck Tire | Nitto Tire

The Ridge Grappler features a revolutionary dynamic hybrid tread pattern and provides a quiet and comfortable with off-road performance capabilities.

www.nittotire.com

For a non-built LC, i.e. no bumpers, winch, kitchen sink, shouldn't a standard P tire be sufficient over an LT? I would generally say yes for most users needs, but those who have placed additional demands on the tire may/do need the LT.

As a anecdotal data point, a completely stock LC on street tires did way more than just gravel roads in Breckenridge 2017.

Just FYI, that Nitto Ridge Grappler is NOT a P-Metric tire, it is an ISO-Metric 285/70R17 116Q SL tire which has a Recommended Cold Tire Inflation Pressure of 33psi F/R.

HTH

 

[Itsky]

Take a look at BFG 285/70/17 load range C if your considering rock warrior wheels, makes for a nice lightweight option.

I believe the stock wheels and tires weigh about 72 lbs, and the noted combination is about 74-76 lbs.

That’s the direction I went.

 

[bloc]

The elephant in the room for all these tire discussions is the law of physics. There is no getting around the fact that compared to a stock P285/60R18 tire; ANY tire that is larger in diameter, heavier, or has more rolling resistance (i.e. more aggressive tread) will yield:

- Slower acceleration
- Longer braking distance
- Worse gas mileage
- Poorer performance during aggressive maneuvers

These are the trade-offs we must consciously decide to make for better offroad performance and/or increased durability.

Your choice of a P285/70R17 tire @ 27psi will give you a more comfortable ride, but will still result (perhaps to a lesser degree than an LT-Metric tire) in all the trade-offs mentioned above - plus they will be less durable (resistant to puncture, etc.).

I can't tell you what is more important to you - you have to make that decision. But I can leave you with one word of caution: The P285/70R17 Toyo's you are looking at are an SL (Standard Load) tire. Usually, P-Metric tires for the LC200 are XL (Extra Load) tires. The SL tire will be more susceptible to failure under any dynamic load conditions like hitting a pothole, running over a curb, etc.

I have been doing a little digging and can't find a single P-metric 285/75/17 that is XL rated.. and yet these things are too big to go on passenger cars.. would need to be truck or SUV only.

What are the substantive differences between an SL and XL constructed tire? I know you can run more pressure in the XL, but does it have a 30% thicker casing or anything? Same question for euro-metric, for that matter.

And while I do understand the physics element, these tires being a very similar weight and pressure to stock should make the "ride" side of things similar to stock. I get that even with a similar weight wheel/tire, if it is larger diameter it'll impact gearing and torque at the wheel.. but I can deal with this.

Bloc, I am looking for RW's now to replace my stock 20's and your concerns are similar to mine. I use my LX mainly as transport to hunting and fishing places. Things I don't wanted, a puncture while in the outback, decreased mpg, and significant change in handling. I am waffling between XL's and E but won't even look at P's I don't want to loose a the time changing a flat might take when loaded with all my crap. Everything is a trade off, that said every year I see trucks fixing flats on rough forest service roads due to speed and s***ty OEM tires.

Your 80 was my inspiration until a wind storm snapped a tree and totaled it. Funded my LX but still miss my 80 and she would have had an LS by now.

Thanks for the kind words about my 80.. it's a testament to both how great this 200 is and how I use my cruisers that I don't really miss the 80 at all... as cool as it was.

What tires would you be getting XL but not P?

Take a look at BFG 285/70/17 load range C if your considering rock warrior wheels, makes for a nice lightweight option.

I believe the stock wheels and tires weigh about 72 lbs, and the noted combination is about 74-76 lbs.

I noticed that and seriously considered it, but two problems: still need to run 40+ PSI just like my LT-E tires which will give a similar (bad) Tire Spring Rate (thanks for the terminology Gaijin).. and this is 100% vain but I wanted the option of white lettering based on pics I've seen of rock warriors on other white 200s.

The lettering alone wouldn't be enough to get me but I think the tire pressure is too high for what I'm hoping to achieve.

 

[Itsky]

I have been doing a little digging and can't find a single P-metric 285/75/17 that is XL rated.. and yet these things are too big to go on passenger cars.. would need to be truck or SUV only.

What are the substantive differences between an SL and XL constructed tire? I know you can run more pressure in the XL, but does it have a 30% thicker casing or anything? Same question for euro-metric, for that matter.

And while I do understand the physics element, these tires being a very similar weight and pressure to stock should make the "ride" side of things similar to stock. I get that even with a similar weight wheel/tire, if it is larger diameter it'll impact gearing and torque at the wheel.. but I can deal with this.



Thanks for the kind words about my 80.. it's a testament to both how great this 200 is and how I use my cruisers that I don't really miss the 80 at all... as cool as it was.

What tires would you be getting XL but not P?



I noticed that and seriously considered it, but two problems: still need to run 40+ PSI just like my LT-E tires which will give a similar (bad) Tire Spring Rate (thanks for the terminology Gaijin).. and this is 100% vain but I wanted the option of white lettering based on pics I've seen of rock warriors on other white 200s.

The lettering alone wouldn't be enough to get me but I think the tire pressure is too high for what I'm hoping to achieve.

They need 40 psi. No bad ride characteristic. They’re a no brainer

 

[speyrod]

Thanks for the kind words about my 80.. it's a testament to both how great this 200 is and how I use my cruisers that I don't really miss the 80 at all... as cool as it was.

What tires would you be getting XL but not P?


I just feel the P metric is too light of duty and prone to punctures etc. I'm not certain what I am going get looking at my options. I ran E rated BFG A/T 33" on the 80 and loved them. Also in consideration is 2 set of wheels, something like fall to spring (fishing/hunting seasons) tow the boat, road trip season.

My 80 was very clean and I settled at about 75% of what my LX cost me. I am a believer in keeping it clean and well documented

 

[gaijin]

I have been doing a little digging and can't find a single P-metric 285/75/17 that is XL rated.. and yet these things are too big to go on passenger cars.. would need to be truck or SUV only.

What are the substantive differences between an SL and XL constructed tire? I know you can run more pressure in the XL, but does it have a 30% thicker casing or anything? Same question for euro-metric, for that matter.

And while I do understand the physics element, these tires being a very similar weight and pressure to stock should make the "ride" side of things similar to stock. I get that even with a similar weight wheel/tire, if it is larger diameter it'll impact gearing and torque at the wheel.. but I can deal with this.

As for the part of your post aimed at me:

Don't know where P285/75R17 tires came from, I thought we were talking about P285/70R17.

XL is rated for a higher Load Limit than SL. ISO-Metric (your "euro-metric") is a different tire standard and comparative Load Limits will vary based on the Load Rating (e.g. 114, 116, etc.) for any particular size.

If the effects of a larger diameter wheel/tire are OK with you, then go for it.

Don't misunderstand me, please. You can choose any tire you want. As long as it meets the minimum required Load Limit and doesn't rub anywhere on your truck you will have a safe ride. Just trying to let you know what some of the trade-offs are. SL is less durable than XL. P-Metric and ISO-Metric are less durable than LT-Metric.

Hope you find the best solution for you.

HTH

 

[TeCKis300]

Please fact check me, but IIRC, the Toyo Open Country AT II was first released sometime back in 2012. It was very high on my list of tires on my prior car when they were newly released. Toyo is Nitto's parent company, and the Open Country AT and Nitto Terra Grappler with shared technology both went to a "II" model at the same time. The change was largely due to the newly introduced harder wearing tire compound. That was both incrementally firmer riding and noisier, for the benefit of added tire life.

If your priority is tire NVH, there may be newer generation tires available in the market that supersede the technology in the AT II.

Otherwise, I think you have a great plan being realistic about what you want in a tire.

 

[bloc]

To further complicate things.. just realized not many tires carry the "3-peak" aka 3PMSF designation like my current KO2s. Could be important for future ski trips.

Starting to make the case for some C-load KO2s and hoping the fact that I save 13# per corner vs my current setup is enough to make up for not being able to lower the pressure (as I made clear in my first post.. I think that is a big part of the ride quality problem) and maybe that the lighter construction of LT-Cs will save some fuel.

Just a point of info for people wondering about my ride quality issues.. I'm using new OEM shocks and think they just aren't valved to handle the weight of an e-load tire and probably the TSR when you include the higher cold inflation pressure. Upgraded suspension might do better and address my complaints, but I want to keep stock height for now.

Don't know where P285/75R17 tires came from, I thought we were talking about P285/70R17.

XL is rated for a higher Load Limit than SL. ISO-Metric (your "euro-metric") is a different tire standard and comparative Load Limits will vary based on the Load Rating (e.g. 114, 116, etc.) for any particular size.

If the effects of a larger diameter wheel/tire are OK with you, then go for it.

Don't misunderstand me, please. You can choose any tire you want. As long as it meets the minimum required Load Limit and doesn't rub anywhere on your truck you will have a safe ride. Just trying to let you know what some of the trade-offs are. SL is less durable than XL. P-Metric and ISO-Metric are less durable than LT-Metric.

Your knowledge definitely helps. thanks.

Sorry, meant 285/70 not 75.

I guess what I mean to ask is within P-metric, is SL really "that much" more prone to failure than XL? Or are we talking a very small difference? And any idea why there wouldn't be any XL tires in this size?

Please fact check me, but IIRC, the Toyo Open Country AT II was first released sometime back in 2012. It was very high on my list of tires on my prior car when they were newly released. Toyo is Nitto's parent company, and the Open Country AT and Nitto Terra Grappler with shared technology both went to a "II" model at the same time. The change was largely due to the newly introduced harder wearing tire compound. That was both incrementally firmer riding and noisier, for the benefit of added tire life.

If your priority is tire NVH, there may be newer generation tires available in the market that supersede the technology in the AT II.

I have learned that mileage and NVH do actually matter.. five years ago it was MT or nothing. So yeah it is something of a priority, but it's a matter of finding the balance. I could put a street tire on it and cruise around in blissful silence, then slip 100ft off the side of a muddy powerline road into the canyon floor. (almost did that in my 80 with Defender LTXs)
There just aren't many AT tires in this size in P-metric or ISO-metric. And as mentioned the SL vs XL issue.

 

[Yossarian]

Just FYI, that Nitto Ridge Grappler is NOT a P-Metric tire, it is an ISO-Metric 285/70R17 116Q SL tire which has a Recommended Cold Tire Inflation Pressure of 33psi F/R.

HTH

Now I need to look up what the difference is between the two. Thanks for keeping it accurate gaijin.