I have my cars serviced/repaired by an absolute first class and very knowledgeable mechanic. Today I had him remove the snow tires from my wife's car. I know it's June, but while the tires had plenty of tread left, there was not enough for another winter. So I thought I would just leave them on there for now and wear them out rather than her summer tires. One tire picked up a nail so rather than have it repaired, I just had him put on the summer tires.

He told me that it is a mistake to use the snow tires in summer, even though worn and appearing like summer tires, on the car. I don't remember exactly what he said, but it had something to do with ruining/damaging the wheel bearings, and maybe some other damage. The car is a 2001 Jag S-Type.

I told him I can't see how using the snow tires would cause any damage to the car, but he insisted it would. What do you guys think?

 

Snow tires have less rolling resistance which can increase wear and tear on hub and axle components in theory.

My main concern would be safety. Your snow tires aren't designed to be used in higher temps, and they actually have significantly less grip and traction than season appropriate tires.

 

Winter tires in warm weather is a safety issue. Braking, and stability is reduced. Wear and tear no way. Things that cause more pressure on the wheel bearings, and suspension. Things not like changing your et60 wheels to an et 45. Going with wider tires. Improper wheel alignment can cause extra stress on those parts. I am not saying you can't or shouldn't. I'm saying it put more stress on the wheel bearings and suspension. With that said I have done both of those things with my s-type. When I lived in Michigan I ran winter tires. I have even driven cross country with snow tires on. Going from cold to warm. I have not had an issue. That statement must be some kind of myth he has heard. By the way I am a mechanical engineer. The only way tire compound can be a contributor to drivetrain damage would be with extra grip. This would only be true on the drive wheels. Instead of the tires spinning they hook up, and the axels, rear gear, drive shaft, transmission all now have greater stress. Now sticker tires on the front can have more stress on steering components. Winter tire in the summer do not have better grip. You can smoke those things readily.


Bye the way, 3.0 or 4.0?

 

Because rubber gets harder with colder temperatures, winter tires use really soft rubber so that they are the right hardness in the cold weather. That is the main reason they say you should use winter tires rather than all-season tires in the winter. They say that all-season rubber becomes too hard to offer the best traction when temperatures fall below 7deg Celsius / 45deg Fahrenheit.

Summer / performance tires would become too hard at even higher temperatures than all-season tires, since they are designed for a certain hardness at high temperatures.

So running with winter tires in the summer means that you are driving on really soft rubber, and if your winter tires have blocky treads, they will squirm, which means the handling ability of your car on winter tires in the summer is terrible and perhaps even unsafe. And squirmy tires are going to put loads on your wheels, suspension, bearings that they were not designed for.

 

Wow, thanks for those responses guys. You brought up lots of considerations that I hadn't even, well .... considered. I appreciate all the info.

Coleroad, her car is the 3.0 V6 version. It turned 15 years old last March and has 157,000 miles on the clock. The car still looks great, and (knock on wood) still runs great. Do you still have your S-Type?

 

Wear and tear on anything other than the tire shouldn't be an issue, but grip will probably be reduced - meaning longer braking distance and less stability in cornering. Whether that makes the tires a safety issue is another matter entirely.

Under relatively normal temperatures, it shouldn't be a problem - after all, people who use winter tires leave them on until winter weather is done for the season; obviously, they don't switch them every day depending on the temperature. But I recall an extreme temperature test done with winter tires (I think Xi3's) where at ambient temperatures above 100°F, the testers were able to get the winter tires to marble on the racetrack.

 

OH yes, I still have mine. Mine is a 4.0, 2000 with 91,000 miles.

 

So running with winter tires in the summer means that you are driving on really soft rubber, and if your winter tires have blocky treads, they will squirm, which means the handling ability of your car on winter tires in the summer is terrible and perhaps even unsafe. And squirmy tires are going to put loads on your wheels, suspension, bearings that they were not designed for.[/QUOTE]

If that were true then bias ply tires would have chewed up millions of cars. There is less squirming from a winter tire than a bias ply. Those things follow every little grove in the road.

 

Cars had much less sophisticated and less technical suspension and hub setups when people used bias ply tires.

Put bias ply tires on a modern car and see what the effect is.

 

Not really, McPherson struts have been around since the 50's. Rack and pinion steering by bmw in the 30's. Ball joints in the 50's. The fact of making a sealed wheel bearing assembly is all that is more recent. That isn't handling any different forces. It is better because they don't get maladjusted, don't let dirt and water in. What has really changed in steering and suspension is better geometry, lighter cars, lighter wheels. Even these things aren't new. They have just become mainstream over time. Low profile tires put extra force on the steering and suspension. It's lack of ability to absorb forces both on a horizontal and vertical plane puts more stress on other components.

If you take a pencil put a nail through the center of it. Mout it to a a block of wood that has had a hole drilled into it and filled with wax so the nail is held by the wax eraser down to the table. Do the same thing again but take a coping saw and make multiple cuts perpendicular to each other. Making sure they are both applying the same amount of down force on the eraser. Now push the block latterly until the nail touchs the wood. You will see that the block with the smaller squishy eraser has to be pushed further to create enough force to push the nail up to the wood. The malleable tread absorbs some of the lateral force rather than the spindle and wheel bearings having to.

 

Bear in mind I don't think running the snow tires will harm the suspension or hub assemblies, my issue is just the comparison to the effect bias ply tires had on cars.

It's true the basic technologies may have existed, but they weren't mainstream, and the implementation is much more intricate elaborate today. For instance find me a car back when we had bias ply tires that had 8 control arms per wheel in a front suspension?

 

I drive on Bias plys all the time on my classics... I love how they squeal heheheh...

But your mechanic is partially right, the difference with winter tires is that above about 40-45F the tread compound is very much out of its' element and does not grip well at all much as summer tires can be lethal at or below freezing, even when the road is dry.

Neat car BTW, I am down to 3 Jaguars... love em.

 

I'm thinking I want to be you LOL