XL Tire Load Rating

Status
Not open for further replies.
Joined
Apr 24, 2009
Messages
1,156
Location
FL - Gulf Coast
What effect would a higher load rated tire have on ride and handling?

For example, installing 107T tires on a 2012 Escape with stock tired rated 104T.
 
The XL tires have a stiffer sidewall and will ride a bit more 'rough'. Probably will respond quicker too as they have stiffer sidewalls.
 
Expect a rougher ride, more tire noise, and better durability for sure.

Better steering response may or may not pan out, though you'd certainly expect it if all else were equal. I've had poor steering response from XL-rated tires, and I've had good steering response from tires that seemed to have squishy sidewalls...
 
I got XL tires on my SC300, they sure are stiffer! I rather like it. Aside from a bit of a stiffer ride, I really didn't notice much difference. *MAYBE* a little more noise, but not much and it could be all in my head.
 
XL tires will typically weigh more than SL tires... more unsprung weight generally translates into a rougher ride. Then again, if the suspension was designed around a heavier wheel and tire package from the get-go, you could hurt the ride quality by going a lot lighter.

At the end of the day, though, tire pressure will have a bigger impact on ride and handling than SL vs. XL tires. So don't sweat it.
 
Originally Posted By: leeharvey418
XL tires will typically weigh more than SL tires... more unsprung weight generally translates into a rougher ride.


This would be my biggest concern. I've experienced rather dramatic differences in vehicle response by shedding a few pounds of unsprung mass, either in the tires or the wheels themselves.

I don't know the exact model of tire you're looking at, but I assume that you're looking at the 235/70R16 size here, and I assume that you're looking at the Firestone Destination LE2, with its 107T service description. That tire weighs 31 pounds. Compare that with the weight of a comparable BFGoodrich Long Trail T/A Tour, another all season light truck tire, and it weighs in at 33 pounds. So the XL-rated Firestone is actually lighter than the standard load BFGoodrich. Interesting.
 
I wouldn't bother going XL

If you want to beef up the tire of a predominatly road vehicle, do like I did and just bump the speed rating.
2 of my vehicles were OEM'ed with S and T speed ratings
I generally go to H, and no further.
 
In this case, the Firestone LE2 in his size is ONLY offered in XL. So I presume he's not specifically looking for an XL tire. I suspect he wants the LE2 and is just checking in first to be sure it won't ruin his ride.

And I'm impressed. Most people don't notice or don't care about such details. Kudos to the OP for the attention to detail!
 
Originally Posted By: leeharvey418
XL tires will typically weigh more than SL tires...

Very true! This could also mean worse fuel economy, acceleration, and braking, all else equal...
 
My minivan came with 98 spec weight rated tires. It is a relatively heavy vehicle and rides better and more securely with 102 spec tires.
 
Yes I was looking at the LE2's, they are on sale right now.

Thanks for the info that is what I suspected but have never gone up in load rating before. I have changed speed ratings on cars before and the difference is night and day.

Load and speed ratings seem to be all over the place in this size. I see S, T and H speed ratings with 104-107 load ratings. All in different combinations.
 
Originally Posted By: tcp71
My minivan came with 98 spec weight rated tires. It is a relatively heavy vehicle and rides better and more securely with 102 spec tires.

Same tire with different load ratings, or different tires?
 
Originally Posted By: stranger706
I have changed speed ratings on cars before and the difference is night and day.

Unless you've actually gotten the same model of tire in two different speed ratings, it would be more accurate to say that you've changed tires before and the difference is night and day.
 
Originally Posted By: stranger706
Load and speed ratings seem to be all over the place in this size. I see S, T and H speed ratings with 104-107 load ratings. All in different combinations.


There is a combination of things going on here.

Speed rating. Yes, there are offerings in S, T, and H in this size. It's nice to see more H-rated tires offered in otherwise "unsporty" sizes such as this one.

Load index. The standard load index for this P-metric size (P235/70R16) is 104. The standard load index for this size without the P- designation, sometimes called "E-metric" or "Euro-metric" (235/70R16) is 106. Then the eXtra Load (XL) version of the P-metric line has a load index of 107.

Surfing Tire Rack, I think nearly every combination is available. It's interesting that Firestone has chosen to make its Destination LE2 available only in the XL/107 version. There must be a vehicle out there that takes this size and that requires the 107 load index and they're trying to capture that market.

My hope for the tire industry is that they'll standardize on either P-metric or the "E-metric" (no P) size and load tables. My Honda CR-V technically takes E-metric tires (225/65R17). Other SUVs and minivans (such as the Equinox and Grand Caravan) take the P-metric P225/65R17. The P-metric load index is 100 and the E-metric load index is 102. So you have some tires out there in P225/65R17 100 and you have some tires out there im 225/65R17 102. Although many industry resources say that these tire sizes are essentially interchangeable, some tire websites force you to select whether or not your tires have that preceding P or not, and it ends up not showing you the available E-metric tires in your size (or vice versa).

CapriRacer, see what you can do about this...
wink.gif
 
Originally Posted By: stranger706
What effect would a higher load rated tire have on ride and handling?

For example, installing 107T tires on a 2012 Escape with stock tired rated 104T.


For practical purposes, you won't be able to tell the difference - as the difference between tires (meaning make and model) is going to be greater than the difference between an SL and an XL.
 
Originally Posted By: Hokiefyd
.........My hope for the tire industry is that they'll standardize on either P-metric or the "E-metric" (no P) size and load tables. My Honda CR-V technically takes E-metric tires (225/65R17). Other SUVs and minivans (such as the Equinox and Grand Caravan) take the P-metric P225/65R17. The P-metric load index is 100 and the E-metric load index is 102. So you have some tires out there in P225/65R17 100 and you have some tires out there im 225/65R17 102. Although many industry resources say that these tire sizes are essentially interchangeable, some tire websites force you to select whether or not your tires have that preceding P or not, and it ends up not showing you the available E-metric tires in your size (or vice versa).

CapriRacer, see what you can do about this...
wink.gif



There's good news and there's bad news:

It's been known for many, many years that the issue of P metric vs Eurometric, vs Japanmetric has been causing confusion. Since each type of tire is - for practical purposes - interchangeable with any of the others, there's not a lot of pressure to fix this.

Then there is the issue of each area having a vested interest in continuing their own way of doing things. While everyone would like to make them the same, the hurdles are very difficult.

So I think it is going to take a complete change in sizing structure - that is, there will be a completely new way of describing a tire's size. For example, I had a set of race tires where the overall diameter was written in metric units, the width was written in metric units, and the rim diameter was in inches: 600 X 250 R 13.
 
Originally Posted By: CapriRacer
So I think it is going to take a complete change in sizing structure...


Speaking of that, do you know why tire widths always seem to end in '5'? Why aren't there any 200/70R15s?
 
Originally Posted By: CapriRacer
Originally Posted By: stranger706
What effect would a higher load rated tire have on ride and handling?

For example, installing 107T tires on a 2012 Escape with stock tired rated 104T.


For practical purposes, you won't be able to tell the difference - as the difference between tires (meaning make and model) is going to be greater than the difference between an SL and an XL.


Good to know! Thanks
 
Load capacity is a function of air volume and pressure.

You can influence a given tire one way or the other by changing the width of the wheel.

When looking at tire specs, the manufacture will supply a wheel width range such as 7.5-9.0

The wheel width in brackets (8.0) is the wheel width that the load index was established.

You can increase the air and load capacity by choosing the widest wheel stated, by increasing the pressure or both.

XL rated tires may nor necessarily be of a more robust construction, but a slightly larger dimension than the standard load tire of the same size.

Speed ratings are different because they must carry a specified load at a higher speed which necessitates a tougher construction.

Speed and high loading is present on banked ovals where downward force may double a vehicle's weight.
 
Originally Posted By: used_0il
Load capacity is a function of air volume and pressure.....


That is true, but that is far from all the factors.

Originally Posted By: used_0il
........You can influence a given tire one way or the other by changing the width of the wheel......


Actually, no. You may think that the larger air volume would help, but what the formula is doing is calculating a deflection - which hardly changes with wheel width.

Originally Posted By: used_0il
........When looking at tire specs, the manufacture will supply a wheel width range such as 7.5-9.0. The wheel width in brackets (8.0) is the wheel width that the load index was established..........


Actually, the number in brackets is the width of the rim where the dimensions were established.

Originally Posted By: used_0il
........You can increase the air and load capacity by choosing the widest wheel stated, by increasing the pressure or both.....


As I said above, that really isn't true. That part about inflation pressure is, but, again, this has to do with deflection and air chamber volume plays a role, but not when it comes to rim widths.

Originally Posted By: used_0il
........XL rated tires may not necessarily be of a more robust construction, but a slightly larger dimension than the standard load tire of the same size......


I have never heard of anyone doing it that way. It's always been a slightly stronger construction - in the same mold. I see lots of issues if someone were to use the air chamber volume as a way to increase load carrying capacity.

Originally Posted By: used_0il
........Speed ratings are different because they must carry a specified load at a higher speed which necessitates a tougher construction......


Not exactly tougher, but the construction has to have something to deal with the centrifugal forces - usually that mean cap plies.

Originally Posted By: used_0il
........Speed and high loading is present on banked ovals where downward force may double a vehicle's weight.


If we are talking about racing, that's a whole different kettle of fish. Best to avoid those type of tires when we talk street tires.
 
Status
Not open for further replies.
Back
Top