The "Hidden" Tire Pressure Specs (US/CAN vs. The World)

[Lazy2.5]

Hi everyone,

I wanted to share a really interesting finding regarding tire pressures that explains why the standard US/CAN door-jamb recommendation can feel a bit "off" (either too harsh when solo or unstable when fully loaded).

Shout-out to user @Mazdiod2 from Mexico for pointing this out originally. They mentioned that their owner's manual actually lists different pressures based on load, whereas we here in the US/Canada just get one static number. Apparently this is the standard for the rest of the world; whereas us North American owners are left being treated as if we will never check our tire pressures.

The "Dummy-Proof" US/CAN Specs:

Because of US regulations (specifically the TREAD Act), Mazda provides a single pressure recommendation on our door stickers. Rather than giving us specific optimizations for different loads, the US spec is essentially a compromise setting (roughly a mix between light and medium load targets). It is designed to be "safe enough" for a full load without being uncomfortably stiff for daily driving.

• Result: We usually see a flat 34 PSI or 35/36 PSI (depending on wheels) regardless of how we actually drive.

The "Real" Engineering Specs (Global)

If you look at the manuals for the exact same car sold in Europe or Mexico (where they trust drivers to adjust for load), the engineers recommend a completely different strategy.

Here is the data from the Official Mazda Owner’s Manual (Global Spec):

CX-5 with 17" Wheels (225/65R17)

• US Sticker: ~34 PSI Square (Always)
• Global Light Load (Up to 3 people): 33 PSI Front / 33 PSI Rear
• Global Max Load (Full trunk/passengers): 38 PSI Front / 41 PSI Rear

CX-5 with 19" Wheels (225/55R19)

• US Sticker: ~35 PSI Square (Always)
• Global Light Load (Up to 3 people): 36 PSI Front / 36 PSI Rear
• Global Max Load (Full trunk/passengers): 38 PSI Front / 42 PSI Rear

The Takeaways:

1. For Comfort (Solo/Daily): If you are just commuting to work, the "Light Load" specs (33 psi on 17s / 36 psi on 19s) are the intended engineering spec for comfort and patch contact.
2. For Hauling (Road Trips): This is the big one. If you load your US-spec CX-5 with 4 adults and luggage, the sticker pressure of 35 psi is actually too low for the rear axle. The engineers recommend bumping the rear up to 41-42 PSI to handle the weight transfer.

IMPORTANT: Winter Tire Adjustment (+4 PSI) Mazda explicitly recommends adding +4 PSI (approx 0.3 bar) to your tires when using Winter Rubber. This compensates for the softer sidewall and the fact that pressure drops significantly once you leave your warm garage.

Why the "Global Spec" Matters Here: If you blindly add +4 PSI to the standard US Sticker (which is already a compromise setting), you might end up with rock-hard tires (e.g., 36 + 4 = 40 PSI). For a solo driver on ice, 40 PSI is too stiff; the tire won't conform to the road surface, reducing grip.

By using the Global Light Load baseline, the math works perfectly:

• Baseline (Light Load): 33 PSI
• Winter Adjustment: +4 PSI
• Total: 37 PSI

This puts you in the "Goldilocks" zone: stiff enough for the cold, but soft enough to actually grip the snow.

Verification Links: You can see these tables yourself on the Mazda Canada/Global manual sites. Look for the table labeled "(Mexico)" or check any European PDF manual.

• Mazda CX-5 Owner's Manual - Specifications

(Disclaimer: Always check your specific tire's maximum pressure rating on the sidewall before inflating to the high-load numbers.)

 

[AL Cx5]

Thank you @Lazy2.5. I've copied this to my 2024 CX-5 maintenance spreadsheet!

A side note: Have you checked behind a dealer or shops after setting the tire pressure? I have found the tire pressure is usually a few pounds under pressure and not consistent across 4 tires. The shops pressure gauges are worn and don't read correctly. The Tech is not overly concerned about getting the pressure to the correct pressure.....

I hand my digital pressure gauge to the guy changing my tires to set the pressures. When I get home, I check behind the guy. OFTEN the tires are STILL off by a PSI or so.

After tire install, I check my own tire pressures. Gives me an opportunity to get up close to the tires and wheels for close inspection.

Part of my Car Yoga routine!

 

[Lazy2.5]

Thank you @Lazy2.5. I've copied this to my 2024 CX-5 maintenance spreadsheet!

A side note: Have you checked behind a dealer or shops after setting the tire pressure? I have found the tire pressure is usually a few pounds under pressure and not consistent across 4 tires. The shops pressure gauges are worn and don't read correctly. The Tech is not overly concerned about getting the pressure to the correct pressure.....

I hand my digital pressure gauge to the guy changing my tires to set the pressures. When I get home, I check behind the guy. OFTEN the tires are STILL off by a PSI or so.

After tire install, I check my own tire pressures. Gives me an opportunity to get up close to the tires and wheels for close inspection.

Part of my Car Yoga routine!

I simply take tire pressure setting into my own hands.

I check tire pressures usually after fairly significant changes in ambient temperature, which occurs frequently here in Canada.

1psi or so is probably no big deal, but I find that it is enough for me to notice a change in handling.

 

[Lazy2.5]

Another thing I wanted to mention is Mazda's recommendation to increase tire pressures by 4psi when running snow tires.

After experimenting with this, I determined that 37psi is the most I am comfortable running when driving with a light load (Typically just me..)

Then sure enough, I literally learned that 33psi is the light load rec. for my car (2015 Mazda 6), so 33+4psi makes perfect sense.

I also tried experimenting with a slightly staggered setup with my snow tires of 37PSI front, 35PSI rear for winter driving, with winter tires in slippery conditions. The chassis is inherently quite tail-happy so long as both front tires have equal grip and the open-diff isn't interrupting the fun. 1-2PSI less for an unloaded rear axle should help make things a bit more playful, if that is your thing. It's mostly been quite a lot of fun counter steering this thing, especially at low speeds.