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.