SL vs XL tires for winter

[redhat]

Last week, I went and got two front WeatherTech mats for the Taurus from a guy off of Craigslist. Turned out, he also had 4 alloy wheels with about finished snow tires for $50. I grabbed them as well.

They are 17" and the appropriate size would be 225/65/17 to match the Taurus 245/45/20. I have noticed that the current (20") tires on my car are XL. I have noticed that 225/65/17 tires can come in SL or XL. How critical is it that I seek out XL tires? It looks as if most of the XL tires are SUV/CUV/crossover types where as the SL ones are usual car tires.

I know speed rating will be different but I do not plan to cruise at anything above 85 (at absolute max) with winter tires. Thanks.

 

[UG_Passat]

What does the owner's manual say?

 

[SatinSilver]

The DT site says SL tires. Some XL tires from my current experience have a stiffer sidewall that can affect ride quality. No way I'd get them again.

 

[redhat]

Nothing about what size or load rating to run.

 

[Johnny2Bad]

You need to look at the full size specification. "225/65/17" isn't enough information.

Pxx tires are Passenger Car rated tires; they come in sizes that fit all vehicles including SUVs and trucks. They are typically smooth riding but handle fewer loads than LTxx tires which will have more plies and ride a bit stiffer. Horses for Courses.

EG:

P225/65/17 is a passenger car tire. The SL and XL designations are just load ratings, but they are not high load rated tires, but can be rated for all highway and ticket-generating speeds up to and beyond 130 MPH

LT225/65/17 is a Light Truck tire. More plies (better puncture resistance), higher load ratings (C, D, etc) and slightly firmer or harsher ride. Generally lower speed rated, perhaps 80 MPH or higher.

You would not want to run an LT tire on a sedan (and there is no need as the sedan can't carry the load anyway) but for an SUV or truck you can consider them as you may be able to use the extra load carrying capacity plus these are heavy vehicles to begin with.

The load rating and speed ratings follow the tire type and size specification; eg:

LT 225/65/R17 94W LRC

"R" at R17 indicates radial, 94 is the load rating, C denotes Load Range which is a combination of construction (plies) and load.

Load will also be indicated directly in pounds / kg at a specific inflation;on the sidewall, other inflations will alter the load capacity and speed capacity. Speed and Load is essentially how much heat the tire can dissipate.

There are also traction and wear ratings on the side of the tire. So everything you need to know (and asked about) can be found from reading the entire sidewall.

WRT the wear of the snow tires, winter tires have less braking and cornering ability than summer or multi-season tires except below 45F, and worn examples may not have much winter traction as well as typically the sticky cold-temperature layer is on the outer area of the tread and once worn past that point it's just ordinary rubber. With winter tires, it's much more important to use them in winter rather than summer (a badly worn summer tire will corner and brake better above 45F than a new winter tire) and to replace them sooner based solely on remaining tread depth. Winter tires also wear much more rapidly at warm temperatures.

 

[knerml]

IF SL tires fit your car, in general they will probably have more compliance and better traction in snow.

 

[Quattro Pete]

Originally Posted By: redhat
Nothing about what size or load rating to run.

You car didn't come with a door placard that lists recommended tire size and pressure?

FYI, according to TireRack, the proper winter tire size is 235/60/17 for your car, but 225/65/17 has the same load rating, so it should work, too.

What is the load rating on your 245/45/20 summer tires? Is it 103? If so, you should get replacement tires with a load rating at least this high. This might mean having to go with an XL rated tire.

 

[Oily_Thing]

Check the door placard!

 

[eljefino]

Make sure your rims clear your brakes.

 

[redhat]

Originally Posted By: Johnny2Bad
You need to look at the full size specification. "225/65/17" isn't enough information.

Pxx tires are Passenger Car rated tires; they come in sizes that fit all vehicles including SUVs and trucks. They are typically smooth riding but handle fewer loads than LTxx tires which will have more plies and ride a bit stiffer. Horses for Courses.

EG:

P225/65/17 is a passenger car tire. The SL and XL designations are just load ratings, but they are not high load rated tires, but can be rated for all highway and ticket-generating speeds up to and beyond 130 MPH

LT225/65/17 is a Light Truck tire. More plies (better puncture resistance), higher load ratings (C, D, etc) and slightly firmer or harsher ride. Generally lower speed rated, perhaps 80 MPH or higher.

You would not want to run an LT tire on a sedan (and there is no need as the sedan can't carry the load anyway) but for an SUV or truck you can consider them as you may be able to use the extra load carrying capacity plus these are heavy vehicles to begin with.

The load rating and speed ratings follow the tire type and size specification; eg:

LT 225/65/R17 94W LRC

"R" at R17 indicates radial, 94 is the load rating, C denotes Load Range which is a combination of construction (plies) and load.

Load will also be indicated directly in pounds / kg at a specific inflation;on the sidewall, other inflations will alter the load capacity and speed capacity. Speed and Load is essentially how much heat the tire can dissipate.

There are also traction and wear ratings on the side of the tire. So everything you need to know (and asked about) can be found from reading the entire sidewall.

WRT the wear of the snow tires, winter tires have less braking and cornering ability than summer or multi-season tires except below 45F, and worn examples may not have much winter traction as well as typically the sticky cold-temperature layer is on the outer area of the tread and once worn past that point it's just ordinary rubber. With winter tires, it's much more important to use them in winter rather than summer (a badly worn summer tire will corner and brake better above 45F than a new winter tire) and to replace them sooner based solely on remaining tread depth. Winter tires also wear much more rapidly at warm temperatures.


Thank you, a lot of good information here. This definitely helps.

 

[redhat]

Originally Posted By: Quattro Pete
Originally Posted By: redhat
Nothing about what size or load rating to run.

You car didn't come with a door placard that lists recommended tire size and pressure?

FYI, according to TireRack, the proper winter tire size is 235/60/17 for your car, but 225/65/17 has the same load rating, so it should work, too.

What is the load rating on your 245/45/20 summer tires? Is it 103? If so, you should get replacement tires with a load rating at least this high. This might mean having to go with an XL rated tire.



Well there is a placard but it lists the 20" wheel size. I'll double check it. The wheels I bought have 225/65/17 so I assumed (and from reading on Taurus forums) that is what the equal 17" size would've been from the factory. But I am starting to find out by looking elsewhere that it is indeed the size you mentioned. Thank you.

 

[redhat]

According to TireRack, the OE tire for my car is Michelin Primacy MXM4 in P245/45R20 99V SL. And the thing does have Primaxy MXM4s on it.

 

[Quattro Pete]

Originally Posted By: redhat
According to TireRack, the OE tire for my car is Michelin Primacy MXM4 in P245/45R20 99V SL. And the thing does have Primaxy MXM4s on it.
But you said yours were XL?

Looking at the specs, Primacy MXM4 in size 245/45/20 is not available as XL.

 

[CapriRacer]

There are a couple of things worth commenting on:

First is that the vehicle tire placard will list not only the tire size, but the load rating (SL vs XL, or in the case of LT tires Load Range), as well as the inflation pressure. As a general rule if the specified pressure is 35 psi or lower, the tire size specified will be SL - and will be XL for up to 41 psi. (Please note: There are a few exceptions.)

Second is that fitting alternative sizes to a vehicle may cross some lines that will require the opposite kind of tire (SL vs XL) - and that has to do with load carrying capacity (Load Index). In that case the inflation pressure has to be adjusted as well.

For example, it is not uncommon for plus sized tires to require an XL where the original tire (the one on the placard) was an SL.

Having said all that, it is OK to use an XL in place of an SL. That's because the XL, when inflated that same as the SL, has, for practical purposes, the same spring rate as the SL. And that's because inflation pressure has a much. much greater effect on spring rate than the casing stiffness.

 

[redhat]

Originally Posted By: Quattro Pete
Originally Posted By: redhat
According to TireRack, the OE tire for my car is Michelin Primacy MXM4 in P245/45R20 99V SL. And the thing does have Primaxy MXM4s on it.
But you said yours were XL?

Looking at the specs, Primacy MXM4 in size 245/45/20 is not available as XL.


I am sorry, when Looking up 245/45/20 on DTD I came across a lot of XL tires so assumed that was what it was... or that it was a common thing for this size. Never had a low-profile tire before.

 

[Johnny2Bad]

Originally Posted By: redhat


I am sorry, when Looking up 245/45/20 on DTD I came across a lot of XL tires so assumed that was what it was... or that it was a common thing for this size. Never had a low-profile tire before.


If the tires specified on the door plaque and installed currently on your vehicle are still currently sold, you can check TireRack dotcom for the full specification for that tire and that size. You could then do the same for the new tire you are considering.

Although it's not everything to check, one spec that is useful when changing wheel and tire size is diameter. If the 20" wheel tire and the 17" wheel tire have similar diameters then they usually will fit, usually will fill the wheel wells similarly for appearance, and usually will not cause spedometer changes (as in 30 mph will still read 30 mph).

A 245/45/20 is a low profile tire.

 

[Quattro Pete]

OP, is this what your tire placard looks like?

If so, just make sure your replacement tires have a load rating index of at least 99. If that means having to move up to XL, so be it, but I don't think you will have to do that.



Originally Posted By: Johnny2Bad
A 245/45/20 is a low profile tire.
Depends how you look at it. A 245/45 tire has the same sidewall height as a 185/60 tire, common on many econoboxes, yet nobody calls it a low profile tire.

 

[CapriRacer]

Originally Posted By: Quattro Pete
OP, is this what your tire placard looks like?

Ah ….. Mmmmmm ….. Not exactly.

Since 2008, this version of the vehicle tire placard has been required on the driver's door frame on all light vehicles sold in the US:

What was posted was the vehicle certification label - and I'm surprised it still has tire info on it. I'm going to do some research to find out what the cert label is required to look like - meaning, perhaps Ford hasn't upgraded the cert label for a long time.

 

[Quattro Pete]

Capri, I was just trying to do a Google image search to find a tire placard for OP's specific car, but I didn't have much luck. What I posted was the best I could find that at least showed OP's tire size and load rating index.

With German cars, I am used to seeing all that tire info right in the owner's manual. With American cars, that seems to not be the case.

 

[redhat]

Originally Posted By: Quattro Pete
OP, is this what your tire placard looks like?

If so, just make sure your replacement tires have a load rating index of at least 99. If that means having to move up to XL, so be it, but I don't think you will have to do that.



Originally Posted By: Johnny2Bad
A 245/45/20 is a low profile tire.
Depends how you look at it. A 245/45 tire has the same sidewall height as a 185/60 tire, common on many econoboxes, yet nobody calls it a low profile tire.

Yes that is what I have, and thanks for the clarification, makes sense. I will definitely seek out at least a 99 load rating. Looks like a lot of the winter tires I'm looking at are 102-103 load rating.

And I don't actually have the tire and loading information mini-sheet. I guess that is one difference of the fact that my 2017 Taurus was a car sold and destined to Canada. Car was in Prince Edward Island the beginning of it's life and then came down here and sold to me. I even have a block heater.