New (to me) GX 460 questions

[bothrops]

I just purchased a 2017 gx460 premium and wanted a little more clearance. After reading some threads on this site and elsewhere, I thought I would go with 275 65 18s in a BFG KO2. As others have indicated, it required some heating and a couple of bolt removals (one per side) on the wheel well lining. I have a couple of questions though regarding this setup on which people might have insight:

1. Tire pressure:
The KO2s I found are an E rated tire that can be filled to 80psi. The tech at discount tire said that 40 is ideal for my GX. He indicated that running a higher psi would unevenly wear the tires and cause a worse ride. I would have thought that a higher psi would make for better/smoother steering, less tire wear and better performance towing (and I two with some degree of regularity). Does anyone have any insight? I am planning on increasing pressure to 65 and seeing if that changes anything.

2. clearance in fender lining:
After massaging the wheel well lining, the clearance is still pretty close. I was wondering if snow would collect in there and cause issues. I kind plan on running snow tires since I replaced the wheels, but maybe not. I was thinking about lifting the vehicle a couple of inches with a lift kit, but am a little hesitant messing around with the suspension (especially the kdss). I would like more clearance but as it is I have a pretty good clearance at the front and rear bumpers and if these tires will ride well with stock suspension, I am inclined to keep it that way for now.
Thoughts?
Thanks!

 

[Bralow]

Your tire guy is correct about the pressure - 40 is accurate.

Correct tire pressure is based on the weight being carried.

80 psi or even 65 psi on a stock truck is going to feel like you are ice skating will be extremely dangerous on wet roads. You will have very little control and it will skid very easily.

Also, it will ruin your tires very quickly - you'll get what is called cupping. They'll be so over-inflated that you will be riding on just a tiny little sliver down the middle of the tire. That section will wear down and the rest won't, ruining your tires.

Read this to understand, follow the tables, and the answer you find will be something like 38-40 PSI.

https://www.toyotires.com/media/3729/application_of_load_inflation_tables_20200723.pdf

You can bump it up some when you are going to be towing, but the corresponding PSI for the tires based on towing weight will not be higher than 50-55 before the tow weight is way way too much for the GX. No need to keep it up that high all the time, only when towing.

80 PSI for towing is for 3/4 Ton trucks carry 10-15,000 lbs.

 

[r2m]

I just purchased a 2017 gx460 premium and wanted a little more clearance. After reading some threads on this site and elsewhere, I thought I would go with 275 65 18s in a BFG KO2. As others have indicated, it required some heating and a couple of bolt removals (one per side) on the wheel well lining. I have a couple of questions though regarding this setup on which people might have insight:

1. Tire pressure:
The KO2s I found are an E rated tire that can be filled to 80psi. The tech at discount tire said that 40 is ideal for my GX. He indicated that running a higher psi would unevenly wear the tires and cause a worse ride. I would have thought that a higher psi would make for better/smoother steering, less tire wear and better performance towing (and I two with some degree of regularity). Does anyone have any insight? I am planning on increasing pressure to 65 and seeing if that changes anything.

2. clearance in fender lining:
After massaging the wheel well lining, the clearance is still pretty close. I was wondering if snow would collect in there and cause issues. I kind plan on running snow tires since I replaced the wheels, but maybe not. I was thinking about lifting the vehicle a couple of inches with a lift kit, but am a little hesitant messing around with the suspension (especially the kdss). I would like more clearance but as it is I have a pretty good clearance at the front and rear bumpers and if these tires will ride well with stock suspension, I am inclined to keep it that way for now.
Thoughts?
Thanks!

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A few things...
First, WELCOME to the forum!
Second, love the color!
I'm running LT285/75R17 BFG MT KM2's that are also rated to 80 psi. I generally run my at 40 psi, but when I'm doing a road trip, like last week traveling up to Lake Tahoe, I'll increase the psi to 60 or 65 for a little better gas mileage. As my rig sits (Builds - R2M 2013 GX460 Overland Build - https://forum.ih8mud.com/threads/r2m-2013-gx460-overland-build.1104719/ ), I was getting almost 17 MPG on the way back from Lake Tahoe to my home in San Clemente, CA, about ~500 miles. I have about 40,000 miles on my tires with about half tread wear, and they are wearing great! When I am in Lake Tahoe, I will drop my psi down to as low as 25 or 30 psi if there is snow/ice on the roads. It give a little larger tire patch for control.

I've never had issues with snow buildup on any of my vehicles that a good bonce or warm weather wouldn't fix. And if you're going to mount snow tires on your factory wheels, I imagine they will be along the factory size and not oversized like your new wheel/tire combo. In short you should be fine.

Regarding suspension, KDSS and even the air-bag suspension on the luxury models is a non-issue for shops that specialize in off-road suspension. I don't know what your end game is for your GX, do you want to keep it mild for fire roads, beaches, simple trails, etc.? A small 1-2" lift would be more than enough while still keeping a good profile with your size tires. In fact, as your read through many of the members blogs about adding suspension, you'll find that many feel the ride after lifting their vehicle is better than stock!

One last word of advice, which I've given on this forum before, plan your end game. Discuss with your significant other if they are to be party to your off road adventures and decide upon what and how you want to build your rig. Plan well and purchase once!

Cheers and enjoy!

 

[bothrops]

A few things...
First, WELCOME to the forum!
Second, love the color!
I'm running LT285/75R17 BFG MT KM2's that are also rated to 80 psi. I generally run my at 40 psi, but when I'm doing a road trip, like last week traveling up to Lake Tahoe, I'll increase the psi to 60 or 65 for a little better gas mileage. As my rig sits (Builds - R2M 2013 GX460 Overland Build - https://forum.ih8mud.com/threads/r2m-2013-gx460-overland-build.1104719/ ), I was getting almost 17 MPG on the way back from Lake Tahoe to my home in San Clemente, CA, about ~500 miles. I have about 40,000 miles on my tires with about half tread wear, and they are wearing great! When I am in Lake Tahoe, I will drop my psi down to as low as 25 or 30 psi if there is snow/ice on the roads. It give a little larger tire patch for control.

I've never had issues with snow buildup on any of my vehicles that a good bonce or warm weather wouldn't fix. And if you're going to mount snow tires on your factory wheels, I imagine they will be along the factory size and not oversized like your new wheel/tire combo. In short you should be fine.

Regarding suspension, KDSS and even the air-bag suspension on the luxury models is a non-issue for shops that specialize in off-road suspension. I don't know what your end game is for your GX, do you want to keep it mild for fire roads, beaches, simple trails, etc.? A small 1-2" lift would be more than enough while still keeping a good profile with your size tires. In fact, as your read through many of the members blogs about adding suspension, you'll find that many feel the ride after lifting their vehicle is better than stock!

One last word of advice, which I've given on this forum before, plan your end game. Discuss with your significant other if they are to be party to your off road adventures and decide upon what and how you want to build your rig. Plan well and purchase once!

Cheers and enjoy!

Thanks!

 

[bothrops]

Your tire guy is correct about the pressure - 40 is accurate.

Correct tire pressure is based on the weight being carried.

80 psi or even 65 psi on a stock truck is going to feel like you are ice skating will be extremely dangerous on wet roads. You will have very little control and it will skid very easily.

Also, it will ruin your tires very quickly - you'll get what is called cupping. They'll be so over-inflated that you will be riding on just a tiny little sliver down the middle of the tire. That section will wear down and the rest won't, ruining your tires.

Read this to understand, follow the tables, and the answer you find will be something like 38-40 PSI.

https://www.toyotires.com/media/3729/application_of_load_inflation_tables_20200723.pdf

You can bump it up some when you are going to be towing, but the corresponding PSI for the tires based on towing weight will not be higher than 50-55 before the tow weight is way way too much for the GX. No need to keep it up that high all the time, only when towing.

80 PSI for towing is for 3/4 Ton trucks carry 10-15,000 lbs.

Thanks. I really appreciate your insight. You addressed the tire pressure concern I had perfectly.