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- 2015 Mazda 6 -- Skyactiv 2.5L NA W/ 91 Octane Tune
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.
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)
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.
(Disclaimer: Always check your specific tire's maximum pressure rating on the sidewall before inflating to the high-load numbers.)
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.
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
- 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
- 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.
- 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.
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.
(Disclaimer: Always check your specific tire's maximum pressure rating on the sidewall before inflating to the high-load numbers.)