245 75 16 Cooper ATs. That's kinda low isn't it? I aired them up to 35 psi, hoping to raise MPG. I got a neat little dual/power inflater from HF.
Door sticker on Tacoma reads 29 psi!
- Thread starter andyd
- Start date
Older Japanese cars, especially before 2000, but possibly up until the mid-2000s, had lower tires pressures than today's cars use. I know 26-29 psi was common in 90s Japanese cars.
My 98 Forester says 29 psi up front, 26-36 in the rear, depending on how loaded the car is.
Newer cars have higher tire pressures because they want to squeeze out a *tiny* bit of fuel economy, and because of those exploding Firestones on the Explorer (which is why TPMS is required now).
My 98 Forester says 29 psi up front, 26-36 in the rear, depending on how loaded the car is.
Newer cars have higher tire pressures because they want to squeeze out a *tiny* bit of fuel economy, and because of those exploding Firestones on the Explorer (which is why TPMS is required now).
My 4Runner says the same thing. Maybe they are trying to soften up the ride? I run 35 psi in everything.
CleanSump
Site Donor 2026
28 - 32 used to be common on all cars. 28 was pretty much standard for bias ply and radials were thought high at 32.
My 2008 Mercedes sedan says 28 on the front! I go 32 and their still soft.
My 2008 Mercedes sedan says 28 on the front! I go 32 and their still soft.
29 psi could be a perfectly adequate pressure for the application.
SammyChevelleTypeS3
$50 site donor 2023
Me too. Been running all at 35psi for many years. Just feel like they all ride and handle better is why I ended up doing that.
I've run 34 cold front/32 cold rear in my foxbody for 25yrs.
225/50/16 front---245/50/16 rear.
They wear tile flat and handle great.
Once warm they read~+4lbs over the cold numbers, the rears a little higher most times
Interesting. My Passat says 35 psi all around and the All Track 38 psi all around.
Lower profile tires.
Hot or cold?
Perhaps it is time for me to talk about how car manufacturers set the tire pressure they list on the vehicle tire placard.
Every vehicle manufacturer does this slightly differently, but all seem to wind up in the same ballpark.
Long before the first vehicle is produced, the vehicle engineers sit down with a list of what the vehicle is supposed to do. Among those things will be ride quality and handling. That pretty much determines the inflation pressure as those 2 properties are closely related to what pressure is in the tires. They also consider how heavy the vehicle is going to be. In the old days, this was a bit of a problem, but with the advent of computers, it's a lot easier!
They then size the tire appropriately to get their target pressure. They use the yearbooks published by the tire standardizing organizations, such as the US based Tire and Rim Association, (TRA) or the European Tyre and Rim Technical Organization (ETRTO).
About 2 years before the first vehicle is produced, these engineers create a list of what tire tests have to be run, and what level the tires must meet. They give that list to their tire suppliers - which is usually a short list of 3 or 4 tire manufacturers. Over the next year and a half, all those tests are run and reviewed, and the targets are adjusted if problems are encountered. Then 6 months before the first vehicle is produced., the tire design is frozen, and equipment is ordered (usually only molds, but sometimes new chemicals are involved!)
All during this process, lots of testing takes place - prototype vehicles, competitor vehicles, prototype tires, etc. The important tire thing here is that they use the inflation pressure used during these tests is the same as what will appear on the placard. By the time the first vehicle is produced, they have an extensive background of testing and they know how the vehicle will ride and handle.
What this all means is that the pressure listed on the placard has extensive background.
Now who wants to talk about the Ford Explorer?
Every vehicle manufacturer does this slightly differently, but all seem to wind up in the same ballpark.
Long before the first vehicle is produced, the vehicle engineers sit down with a list of what the vehicle is supposed to do. Among those things will be ride quality and handling. That pretty much determines the inflation pressure as those 2 properties are closely related to what pressure is in the tires. They also consider how heavy the vehicle is going to be. In the old days, this was a bit of a problem, but with the advent of computers, it's a lot easier!
They then size the tire appropriately to get their target pressure. They use the yearbooks published by the tire standardizing organizations, such as the US based Tire and Rim Association, (TRA) or the European Tyre and Rim Technical Organization (ETRTO).
About 2 years before the first vehicle is produced, these engineers create a list of what tire tests have to be run, and what level the tires must meet. They give that list to their tire suppliers - which is usually a short list of 3 or 4 tire manufacturers. Over the next year and a half, all those tests are run and reviewed, and the targets are adjusted if problems are encountered. Then 6 months before the first vehicle is produced., the tire design is frozen, and equipment is ordered (usually only molds, but sometimes new chemicals are involved!)
All during this process, lots of testing takes place - prototype vehicles, competitor vehicles, prototype tires, etc. The important tire thing here is that they use the inflation pressure used during these tests is the same as what will appear on the placard. By the time the first vehicle is produced, they have an extensive background of testing and they know how the vehicle will ride and handle.
What this all means is that the pressure listed on the placard has extensive background.
Now who wants to talk about the Ford Explorer?
Cold.
Tires are always measured (for 'correct' PSI) when cold.
Cold. Always.
I remember the 3rd gens having that low of PSI on the sticker. I always put 33 in the two I had. Current 4th gen recommended 35 with the factory 245/70/17. I run 36 on the 265/70/17's.
