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cidley69
02-23-2021, 10:19 PM
Most Google search results say to use the owners manual specs, or the ones on door frame.

If that's true, why do tires have a range printed on sidewall?

If you have lower profiles than stock, should you ignore manual specs and go with pressure on tires?

killramos
02-23-2021, 10:29 PM
That is maximum safe pressure not a recommended pressure. Use what’s written in the door. Do not fill up your tires to the pressure written on the sidewall.

ExtraSlow
02-23-2021, 10:30 PM
The number on the tire sidewall is the max, and shoukd be used for max load. If you are running stock sixe and load rating tires, the number on the door-jamb sticker is about right for normal use.

Unless you drive a pickup truck, then the answer is much more complex.

tirebob
02-24-2021, 09:16 AM
As ExtraSlow pointed out, what you see on the tire is maximum pressure for maximum load and not a broadly proper operating pressure. You also need to understand that what you see on the door is recommended pressure based on the tire the car is issues with. If you make changes to the size and load carrying capacity of the tire being used, it may warrant an alteration in pressure.

Check out the load and inflation tables at this link. It is a bit to digest but it will give you maybe a better understanding of how to approach air pressures based on the tire specs you are using.

https://www.toyotires.ca/sites/default/files/application_of_load_inflation_tables_20170203.pdf

haggis88
02-24-2021, 10:00 AM
Mercedes try to make it idiot proof, but most owners don't even know this exists on the car. No idea how they miss it, unless they go to the serviced fuel pumps and therefore don't open their own fuel cap

97720

HiSpec
02-26-2021, 01:52 PM
Speaking of tire pressure, what pressure gauge do you guys use? I have three different pressure gauges (dial, stick and air tank pump) and they all provide different readings.

ThePenIsMightier
02-26-2021, 01:56 PM
Speaking of tire pressure, what pressure gauge do you guys use? I have three different pressure gauges (dial, stick and air tank pump) and they all provide different readings.

Air tank pump is as accurate as asking a toddler, in my experience.

tirebob
02-26-2021, 01:57 PM
Speaking of tire pressure, what pressure gauge do you guys use? I have three different pressure gauges (dial, stick and air tank pump) and they all provide different readings.All gauges get fucked over time. The moisture in air causes them to get dirty and sticky. Dial is usually your most accurate long term. Generally the one that reads the lowest is the one I am going to trust the least, but we are always switching out gauges for this exact reason. In the grand scheme of things, even if it is not perfectly accurate, it is more important they are all measured with the same gauge for consistency between tires. You can always tweak a little bit based on handling and wear characteristics.