Who is switching to winter tires and steel wheels?

[Lazy2.5]

@Mazdiod2 So I dug around and verified this information:

CX-5: https://owners-manual.mazda.com/gen/es/cx-5/cx-5_8hd7sp18k/contents/10020109.html

Here is Gemini's explanation as to why only Mexico got the more detailed recommendation:

(I asked: why does only mexico get more detailed tire pressure recommendations?)

This is a classic case of "Litigation vs. Engineering."

The reason you see detailed, variable pressures for Mexico (and Europe/Japan) but a single, high number for the US and Canada comes down to one specific US law: The TREAD Act of 2000.

Here is exactly why the manuals differ, despite the cars being mechanically identical.

1. The TREAD Act (The "Dummy-Proofing" Law)​

In the late 90s, the Ford Explorer / Firestone tire scandal caused hundreds of rollovers.1 The investigation found that Ford had recommended a low tire pressure (26 psi) for comfort, but owners let it drop lower, and when the SUV was fully loaded, the tires overheated and blew out.

In response, the US Congress passed the TREAD Act, which mandated strict rules for the "Tire and Loading Information" placard on the door jamb.

• The Rule: The placard must display the recommended pressure that's biased toward the maximum load rating.
• The Consequence: Manufacturers are effectively banned from putting a "Light Load" number on the official door sticker in North America. If they put "33 psi" on the sticker, and you load 5 people and drive 80mph, they could be liable if a tire blows.
• The Result: They just print the "Max Load" (or near max) number as the only number to cover their legal bases. They assume you will never change your pressure, so they force you to run the "Safe for Heavy Load" pressure 100% of the time.

2. Mexico (and the World) Trusts the Driver​

Mexico does not fall under the US NHTSA TREAD Act regulations for domestic labeling. They generally follow ECE (United Nations/European) standards or their own NOM standards, which prioritize Engineering Optimization over "worst-case scenario" legal safety.

• The Logic: "A car handling 1 driver needs different pressure than a car handling 5 adults."
• The Benefit: By allowing the "Light Load" (33 psi) recommendation, the Mexican spec car rides softer, has a larger contact patch, and wears tires more evenly when you are driving alone (which is 90% of the time).

Summary: The US/Canada label assumes you are clueless and might load the car with bricks at any moment. The Mexican label assumes you are an active participant in maintaining your vehicle.

 

[Mazdiod2]

The Mazda manual specs 41psi for full load vs 33 psi rear (w 17"); 36psi vs 42psi(w 19").

The US spec doesn't give the higher number which should be safer with a heavier load, at least according to this "tread act".

The US spec also doesn't show any difference between the front and rear, while the Mexican spec does.

I don't know who Gemini is, but it doesn't make sense to me. If the manual said to alway inflate to the higher load numbers, which range from 38 to 42 psi, it would make sense.

CX-5: https://owners-manual.mazda.com/gen/es/cx-5/cx-5_8hd7sp18k/contents/10020109.html

Here is Gemini's explanation as to why only Mexico got the more detailed recommendation:
US and Canada comes down to one specific US law: The TREAD Act of 2000.

Here is exactly why the manuals differ, despite the cars being mechanically identical.

• The Rule: The placard must display the recommended pressure for the Maximum Load Rating of the vehicle.
• The Consequence: Manufacturers are effectively banned from putting a "Light Load" number on the official door sticker in North America. If they put "33 psi" on the sticker, and you load 5 people and drive 80mph, they could be liable if a tire blows.
• The Result: They just print the "Max Load" (or near max) number as the only number to cover their legal bases. They assume you will never change your pressure, so they force you to run the "Safe for Heavy Load" pressure 100% of the time.

 

[Lazy2.5]

The Mazda manual specs 41psi for full load vs 33 psi rear (w 17"); 36psi vs 42psi(w 19").

The US spec doesn't give the higher number which should be safer with a heavier load, at least according to this "tread act".

The US spec also doesn't show any difference between the front and rear, while the Mexican spec does.

I don't know who Gemini is, but it doesn't make sense to me. If the manual said to alway inflate to the higher load numbers, which range from 38 to 42 psi, it would make sense.

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You're right. The PSI suggestions in the placard is a compromise number between light and heavy load. I will correct that.

 

[ColoradoDriver]

I use 225/65 17" for both regular and winter tires. I have a cheap alloy set of wheels for the winters, but I actually like them better than my stock wheels looks wise. Very similar look to the 2016 19" wheels (the "vampire fangs").

I have Viking Contact 7's on right now. We've gotten a total of 1 single snowstorm so far this winter. I almost feel like putting my other tires back on.

I had Blizzaks before but given the wild temperature swings and stretches of clear days we can have between major snow events, they just don't hold up for me past 2-3 seasons. Once that initial soft layer of compound is worn out they are noticably way worse.

 

[Lazy2.5]

I use 225/65 17" for both regular and winter tires. I have a cheap alloy set of wheels for the winters, but I actually like them better than my stock wheels looks wise. Very similar look to the 2016 19" wheels (the "vampire fangs").

I have Viking Contact 7's on right now. We've gotten a total of 1 single snowstorm so far this winter. I almost feel like putting my other tires back on.

I had Blizzaks before but given the wild temperature swings and stretches of clear days we can have between major snow events, they just don't hold up for me past 2-3 seasons. Once that initial soft layer of compound is worn out they are noticably way worse.

good lord, we have had at least 10 major snowfalls already here.

 

[ColoradoDriver]

good lord, we have had at least 10 major snowfalls already here.

I have never seen a winter like what we've had so far here in Denver. Seriously, 1 single snowstorm in November. And actually if I am being completely truthful, we got a little bit of snow one night last week but it all melted by noon basically. I am not looking forward to the inevitable drought and wildfire season we are likely to have as a result this summer. The mountains aren't getting much either.

 

[N7turbo]

Same in Nebraska. It has been 50-60° F. Unreal. I'm fully expecting a deep freeze soon to make up for it.

 

[ColoradoDriver]

Same in Nebraska. It has been 50-60° F. Unreal. I'm fully expecting a deep freeze soon to make up for it.

We used to get our heaviest snows in March. Will see what happens this year. We also used to get plenty in November and December, but here we are.

 

[Lazy2.5]

We used to get our heaviest snows in March. Will see what happens this year. We also used to get plenty in November and December, but here we are.

I live on the South-East corner of Georgian Bay, a massive Bay in Ontario just off an even larger Lake Huron. There are literally thousands of lakes all around the vicinity as well, ranging from all sizes.

We are conveniently positioned to receive massive amounts of lake-effect snow, and snow-squalls causing the occasional white-out conditions while driving due to the strong wind. While we rarely get more than 1 foot of snow at a time, it has been occurring on a near-constant basis for most of this winter (so far) as well as the last, with less thawing cycles than previous years. Driving here in the winter is not pleasant, particularly if you decide not to mount winter-tires onto your vehicle.

When the roads are slick enough to cause some loss of traction, but not slick enough to cause a complete loss of control, this is when I am most excited to drive. Mazda's chassis as well as suspension geometry, alignment etc. is setup to offer a very playful rear axle. It's a lot of fun. While the front open diff. can be a let-down in certain scenarios where both front tires have different levels of grip, and pushing hard enough to cause oversteer at higher speeds can be sketchy to say the least, the car is playful when you want it to be while overall proving to be rather capable when simply getting home in treacherous winter conditions is the priority.

I don't have AWD, I don't need it, nor do I want it, unless It was for a car that I use in the winter only. The extra weight and drivetrain losses are useless (IMO) the rest of the time when it is not slippery.

If you have a good car (Such as a Mazda) you know how to drive, have appropriate winter tires mounted, don't drive faster than what the conditions allow, FWD or RWD is perfectly sufficient, especially if you happen to have an LSD.

I have never had issues with ground clearance on my Mazda 6 sedan either, only when pulling into my driveway through nearly a foot of snow.

 

[N7turbo]

I don't have AWD, I don't need it, nor do I want it, unless It was for a car that I use in the winter only. The extra weight and drivetrain losses are useless (IMO) the rest of the time when it is not slippery.

I used to think that.

Then I learned about handling balance and realized AWD fixes FWD understeer/push.

There is a reason RWD cars are easier to turn and feel better when doing so.

 

[Lazy2.5]

I used to think that.

Then I learned about handling balance and realized AWD fixes FWD understeer/push.

The inherit reason why the average car will default to understeer is because they are deliberately setup to do so from the factory. Apparently, it is "safe" for the average driver who may struggle to correct oversteer.

You can tune a FWD car (Such as a Civic Type R) to have very little to no understeer unless you are pushing the chassis to it's limits around a corner.

AWD can assist, but only if the suspension geometry and alignment allows the chassis to rotate properly in the first place.

There is a reason RWD cars are easier to turn and feel better when doing so.

And of course, you are spot-on about the handling-benefits with a RWD (Or even a properly configured AWD) vehicle.


However, to simply tack AWD (Especially one that sends no power to the rear unless it feels the need to) to your average car really isn't going to help with rotation and the mitigation of understeer.

While the CX-5's chassis is inherently a dynamic one and highly capable, the ride height, giant wheels, conservative alignment designed for the average driver, and obese curb-weight no longer positions it as a proper drivers car, in my honest opinion.

If it dropped several - hundred pounds of weight and a few inches in ride height, had some lighter wheels and tires on it, then you could start to work the alignment and AWD system tuning into something worthy of being called a drivers car.

For the average driver, even someone who enjoys to push a little harder around the bends, it's setup great. But no more than that.

 

[N7turbo]

However, to simply tack AWD (Especially one that sends no power to the rear unless it feels the need to) to your average car really isn't going to help with rotation and the mitigation of understeer.

It does and I can tell you there is a very clear difference between the front wheel drive and all-wheel drive CX-5. I have owned both. This is not guessing, it's actual experience. It's pretty easy to understand once you explain that when the rear wheels are pushing, the car rotates better. It's really that simple.

 

[Lazy2.5]

It does and I can tell you there is a very clear difference between the front wheel drive and all-wheel drive CX-5. I have owned both. This is not guessing, it's actual experience. It's pretty easy to understand once you explain that when the rear wheels are pushing, the car rotates better. It's really that simple.

I'm not arguing.

I was referring to the "average car" in the phrase you quoted. The CX-5 is far more competent than the average car, so yes, you are right when you say that AWD will certainly help it handle better.

My main point is that you don't "need" AWD.