Observations going after back to stock oem OT wheels and tires from 35 setup (5 Viewers)

[teghogh]

below are the spec on the 35 setup
Tires:
315-70 17 c rated Goodyear territory mt . These tires are 6 ply , 110 road rating that are by far the lightest 35s in that size at 54lb. Inflated to 35 psi cold .

Wheels :
Method 705s , 35 offset , 25lb , to keep the weight and the scrub radius in check

The combo is relatively light, close to stock offset, with much taller sidewalls relative to stock .

After going back to stock I’ve noticed that the same potholes and road imperfections that made me wish for a smoother ride are now easily handled by stock setup. The ride is about 20 percent smoother

So what gives ?

Is it the extra 10 pounds of rotating mass per corner that negatively impacts suspension dynamics ?

Is it the 15mm offset difference that pushes the wheels out more, acting as a lever on the suspension , transferring more load to steering ?
Any force applied at the tire's contact patch (like turning or road bumps) creates a moment (torque) around the steering axis proportional to the scrub radius.A smaller scrub radius leads to lighter steering and less direct road feedback.

Or is it the c rated vs sl rated oem tires that are causing a stiffer ride ? I would have assumed the difference would have been compensated by extra side wall gained by going to 35s.

My setup was carefully chosen to minimize all the factors that negatively impact ride and handling and yet the impact was noticeable through the unscientific seat of the pants . One interesting note is that I only got a .5 to 1 mpg increase going back to stock .

Ps I can’t wait to ruin the ride again by going to a bigger setup . But this time I may just pick sl rated 18 inch , recon grappler 295 70 18 . These tires are 52 pounds sl rated , 2 ply


Below is a great video comparing sl and c rated tires of the same model

 

[Silver Storm]

Thanks for posting your observation. I too would have thought that a taller sidewall would have meant a smoother ride.

 

[Bluegill]

Note that the video above is comparing Standard Load (SL) to E-rated LT tires, not C-rated LT tires.

 

[Bluegill]

For our relatively heavy trucks, I'm much more comfortable with a C-rated tire vs. the stock SL rating. Look at how many people are posting about the stock Overtrail tires getting punctures on fire roads.

 

[GX550Key]

The Lexus GX is roughly 1,105 to 1,395 pounds heavier than the Tacoma.

 

[bronco21]

Thanks for posting your observation. I too would have thought that a taller sidewall would have meant a smoother ride.

Several factors play into that. It’s not an apples to apples comparison. An MT tire is not the best for on road comfort. Different construction and rubber compound for off road use.

 

[teghogh]

Several factors play into that. It’s not an apples to apples comparison. An MT tire is not the best for on road comfort. Different construction and rubber compound for off road use. Plus we have no idea what PSI the tires were at. Generally PSI required for a specific weight goes down as tire size( air volume) goes up. Many people increase tire size and continue to use the PSI of the smaller tire, decreasing ride comfort.

My tires are not MT. They are standard AT tires . Both PSIs were set at 35 cold.

 

[Bluegill]

GX550 2025 Model	Curb Weight (approx.)	Details
Premium	5,585 lbs	7-seater configuration.
Premium+	5,605 lbs	7-seater configuration with added features.
Luxury	5,675 lbs	7-seater configuration with added luxury equipment.
Luxury+	5,710 lbs	7-seater configuration with the most features.
Overtrail	5,675 lbs	5-seater configuration with off-road enhancements.
Overtrail+	5,705 lbs	5-seater configuration with the most off-road features.

Average of all of the above is 5659.

Difference between lightest (Premium) and heaviest (Luxury+) is only 125 lbs.

I consider these to be heavy trucks. They are right up there with the Cadillac Escalade and Chevy Suburban. I considered my old Land Rover Discoveries to be heavy and they weighed 4465 lbs (1996), 4600 lbs (2004), and 5623 lbs (2013). Although now the relative term "heavy" has to include monstrosities like the electric Hummer at 9500+ lbs.

 

[teghogh]

the two factors that are not fully understood is the impact of offset and heavier wheel tire package on suspension dampening and tuning . I’ll do some research to see how they are impacted .

tires are just about the only item in the consumer market that you can’t experience before the purchase. Think about this. All important factors such as road noise , drivability, etc are a total crapshoot before the install. There are some general rules of thumb but that’s about it . I can’t really find a parallel experience in any other commonly purchased item. There has to be a business case to solve this common issue . If I were to guess I’d say atleast 30 percent of buyers end up unhappy with tire purchases. Maybe it’s time to invest in some software simulation tools or general tire consultant AI tool.
people like us that like to get into the details and do our research still get it wrong now imagine an average buyer that walks into a tire shop and just ask for a bigger tire and ends up with a f load 20 inch falkens on their tundra weighing 80 lbs

 

[teghogh]