Tire Questions

[CooperJohn]

Sorry if this has discussed before but I couldn't find much information on the subject. I'm currently running 17 inch rims on a 3rd generation truck and haul a 3000lb camper most of the time. A few years back both Toyo and Nitto had numerous E rated tires that had higher load indexes than 121 or 3195 lbs. Not so anymore. Why? Nitto has the Dura Grappler that tops out at 3750 for the LT285 75R17 size that I use but that's it. What happened? Are we to believe that the redesigned Toyos are no longer capable of the higher load ratings for 17 inch tires? The 16 inch and 18 inch tires still have options for a higher load index but the 17 inch tires seem to be left in the dust. Anybody know why? I'm really close to maxing out my rear tire load ratings (6000lbs) at the CAT scale with the camper and would like to find a tire with a higher load rating that has an all terrain tread without switching rim size. I have the OEM forged Aluminum rims that I believe are rated for 3500 lbs so a higher rated tire would be nice. Thanks!

 

[Jim W]

My reasoning is that the automotive industry has jumped to 18" or 20" tires for trucks. So, the tire companies have focused on the 18" and 20" tires that seem to have a higher load rating.

All I could find for the 17" tire with a higher load capacity was the Nitto Dura Grappler with a load rating index of 126R. I am using the LT285/70R/17 126R tires on my truck with the Mickey Thompson SideBiter II rims. The tires have a max weight rating of 3750 at 80 PSI and the rims have a max load rating of 3640 LBS.

I do run my rear tires at 70 PSI for a supporting load weight rating of 3415 LBS and the front at 50PSI for a supporting load weighting rate of 2755 LBS when towing my trailer.

If the Nitto Dura Grappler goes out of production and I still have my 2008 truck. I guess I will need to jump to the 18" tire and wheel for my needs.

 

[CooperJohn]

I did dig up some information regarding this issue on another forum. Apparently the Tire and Rim Association(TRA) mandated all 17 inch tires be limited to a load index of 121 or 3195lbs when they are redesigned. So when Toyo joined the TRA they had to limit the load rating printed on their tires each time a new design came out. I'm guessing the same will happen with the Dura Grappler if it is redesigned. Seems a bit odd that this would happen with 17 inch tires only and not 16 inch or 18 inch. I do wonder if the Toyo's that used to be rated at 126R or 128R would still be capable of those loads but just can't say they are? I guess for now if I want the higher rated tires I'll go with the Dura Grappler. Now to decide whether to get the LT285/70R/17 or the larger but much heavier LT285/75R/17. Any feedback on these two sizes from anyone who has run both?

 

[JR]

I know it isn't the info you want but I would be on the look out for a set of 18" OEM take offs from a gen 4 truck. They look good, don't change the offset enough to make a difference on your wheel bearings and have the needed weight capacity. Also lighter than a 285/75/17 that you are looking at which is a benefit all the way around. They can be had for a decent price on Craigslist, Let go, etc. if you aren't in a hurry. I don't have Facebook but Alot of my friends find good deals on their classifieds too.

 

[CooperJohn]

I know it isn't the info you want but I would be on the look out for a set of 18" OEM take offs from a gen 4 truck. They look good, don't change the offset enough to make a difference on your wheel bearings and have the needed weight capacity. Also lighter than a 285/75/17 that you are looking at which is a benefit all the way around. They can be had for a decent price on Craigslist, Let go, etc. if you aren't in a hurry. I don't have Facebook but Alot of my friends find good deals on their classifieds too.

I think you may be correct. Switching to 18" take offs might be the better long term solution. For those who have done this switch, what were the pitfalls if any? I know the bolt pattern is the same and the offset is slightly different. What about the lug nuts, caps and TPMS sensors. Do I use the TPMS sensors from my old 17 inch rims or will the new ones work? I see several 18 inch take offs on Craigslist in my area, both aluminum and clad steel. Most come with new or almost new Firestone Transforce HT tires. I see prices from $350 to $800. Most come with the LT275/70R 18 tires which are pretty close to the LT285/70R17 I have now so maybe my spare tire will be close enough to keep? Decisions?

 

[JR]

Can't answer your questions on the TPMS. But I put a set of 12's on my 98 with zero problems. Offset was negligible. Gen 4 studs did switch to metric thread but the cone of the lug nut didn't change. I used my 98's OE lug nuts for the better part of 75k miles at the time of sale with no problems.

 

[jhenderson]

The guy I sold my 3rd gen to put a set of takeoff wheels with Firestone A/Ts from a 17 on the truck. It was cheaper than buying new tires. He got them from a local tire and wheel store that advertises on Craigslist. They look great.

 

[Dan_69GTX]

Regarding TPMS - yes, it should work fine. I'm unaware of any that are not 433 Mhz sensors. Earlier ones were Schrader and new are TRW - either way who cares. You will need to reprogram the TMPS module for the code on the new sensor. The code is written on the sensor or can be read with a TPMS scan tool.

Another option is to just use your existing sensors in the "new" rims. The valve stems are replaceable. The stem is held onto the sensor by either a screw or pin (varies). Either way - easy to swap.

Or, have someone clone the old sensors so you will have 2 sets with the same codes. This is how almost ALL aftermarket sensors work. Very easy to do. When I put snow tires on my wife's Corolla, that is what I did. Sensors can be bought for about $25 ea. Not sure what the retail of them are.

Here is a site that will help figure out what sensor "might" be in what rim you have.
http://www.maxitpms.com/getCoverage.jspx

 

[Jim W]

On my 08 truck I do not use the TPMS as it is a big pain in the butt to use. I run my truck with out the sensors mounted on the rims. I get 4-dings upon start up an the idiot light stays on. My tire air pressure is check at the beginning of each month and adjusted accordingly.

 

[CooperJohn]

Regarding TPMS - yes, it should work fine. I'm unaware of any that are not 433 Mhz sensors. Earlier ones were Schrader and new are TRW - either way who cares. You will need to reprogram the TMPS module for the code on the new sensor. The code is written on the sensor or can be read with a TPMS scan tool.

Another option is to just use your existing sensors in the "new" rims. The valve stems are replaceable. The stem is held onto the sensor by either a screw or pin (varies). Either way - easy to swap.

Or, have someone clone the old sensors so you will have 2 sets with the same codes. This is how almost ALL aftermarket sensors work. Very easy to do. When I put snow tires on my wife's Corolla, that is what I did. Sensors can be bought for about $25 ea. Not sure what the retail of them are.

Here is a site that will help figure out what sensor "might" be in what rim you have.
http://www.maxitpms.com/getCoverage.jspx

Lots of good info. I went to the maxitpms site and plugged in my vehicle which is a 2008 and as luck would have it, my current TPMS sensors are 315 Mhz. Looks like they switched over to the 433 Mhz the end of 2009. Not a big deal though. I'll use the old style sensors or get an aftermarket system that actually shows the pressures in each tire if I switch over to the 18 inch wheels. The current system is pretty basic and glitchy at best.

 

[CooperJohn]

I made an interesting observation but what does it mean? If you look at the Toyo load inflation tables page 23 and use LT285/70R17 as an example, it shows that tire as a load range E maxing out at 3195 at 65 psi but the tire can be pressurized up to 80psi. I'm going to go out on a limb and assume that the tire is capable of a higher load when filled to 80 psi but because the Tire and Rim association limits 17 inch tires to 3195lbs that's what Toyo stamps on the tire. They also mention earlier in the document that some tires are designated XL or reinforced and are capable of extra load capabilities. I do know that their older versions did in fact garner a higher load rating in this size until they redesigned the tire at which point they were limited by the TRA on what they could say is the load rating. I doubt anyone could ever get confirmation that the tire actually has a much higher load rating than is actually stamped on the tire but I think that may be the case. Thoughts?
https://www.toyotires.com/media/2125/application_of_load_inflation_tables_20170203.pdf