Tire pressure

**isubeatle** · 03-16-2010, 04:53 PM

so i just bought a new car last week and today the tire pressure light came on. so i check the pressure and i'm kinda confused as to what it should be. It's a Toyota and so there's a sticker on the inside of the door and it says all for tires should be 32PSI and the tires themselves say 44PSI. pretty big difference, but i understand that it's different for every car and so that's why there's the sticker on the inside of the door to tell me what's best for my model.

i'm confused by the big difference in the gap there, but also about what the tire's were at. the front two were in the 35ish range while the back ones were in the 40ish range. and i have no idea what they were when i brought the car home 7 days ago but it seems like that's a wide range in difference too. And we havent had any extreme temp changes in the last 7 days either.

i might just take it in, but thought i'd see what you guys had to say. Also, it's a RAV4, so a small SUV in case that helps.

thx!

**Tarbox** · 03-16-2010, 04:56 PM

I thought this thread was going to be about some new defensive back from Texas...

ISU signs Tre Pressure!

First, Hotel Phillips, then Tre Pressure....we can't lose!

**ISUAgronomist** · 03-16-2010, 05:00 PM

Inside the door is correct for the specific model. Tire states the max pressure. Most tire pressure systems will go off for low and high pressure. I'm guessing the system came on for the high pressure in the rear. But it is a Toyota so who knows

**3TrueFans** · 03-16-2010, 05:01 PM

The PSI on the tire is going to be the max pressure most likely. I generally go somewhere in between, 35-38PSI or so.

**Tre4ISU** · 03-16-2010, 05:06 PM

I think your safe anywhere between that range as far as safety. I would probably run them at 35-40. You should get a little better mileage that way. I know the door says 32 but that seems kind of low.

**Tarbox** · 03-16-2010, 05:07 PM

boo....now my post isn't funny or clever.

**Clonefan94** · 03-16-2010, 05:13 PM

My wife had a car with tire pressure senors on them. They would go off for a difference of pressure as well as too low. So if ones out of whack to the rest it will go on too. Hated the things personally and will avoid buying a car with these on them in the future. Even 2 pounds out of whack on any tire and the thing would light up. I'm a stickler for these things anyways and usually check my tires every fill up. So I personally didn't see the need. They are good if you never think about tires though.

**ruxCYtable** · 03-16-2010, 05:25 PM

You should not go by the number on the tire's sidewall. That is the maximum PSI and a lot of consumers make that mistake.

I have an older SUV and the recommended pressure is 28 front, 26 rear, but I don't run them quite that low.

**GoShow97** · 03-16-2010, 05:32 PM

If I'm going on a road trip I'll inflate the tires to max pressure -44 psi - to help with gas milage. Other wise I'll bleed them down to 35 for around town to help with road complience. The trailer and motor home I'll inflate to max pressure. Supposidly on the commercial type tires for trailers you can even go 5 above max pressure. I just make sure I keep them to max. I also carry a pressure guage with me all the time. Inflation pressure is critical for tire life and performance.

**besserheimerphat** · 03-16-2010, 05:43 PM

The number on the door frame sticker is the car manufacturer's recommendation for the stock tires, based on a combination of ride, handling and mpg. If you are running the same make/model of tire as the vehicle was sold with new, then the door sticker is what you should probably run. Understand that higher pressure would yeild higher mpgs and potentially better handling at the expense of ride comfort. Lower pressure would give the opposite - worse handling and mpg with smoother ride.

If you are running tires other than the make/model the vehicle came with, you are kinda on your own. The number on the sidewall is the max you should put in the tire. Running right at that number should be okay, assuming your tire pressure gauge is accurate. If I didn't have a calibrated tire pressure gauge, I'd probably put them around 90% of the max pressure. Fortunately I've got access to highly accurate pressure calibration systems, so I can accurately fill my tires to within a half psi of the max rating because I've calibrated my gauge.

You are safe to run at the max pressure. The max pressure takes into account the dynamic forces that your tires see at temperature extremes, at the max rated speed and at high g-loads.

**isubeatle** · 03-16-2010, 05:57 PM

thx for all the info guys. helps a lot

**swammi** · 03-16-2010, 06:00 PM

Originally Posted by isubeatle

so i just bought a new car last week and today the tire pressure light came on. so i check the pressure and i'm kinda confused as to what it should be. It's a Toyota and so there's a sticker on the inside of the door and it says all for tires should be 32PSI and the tires themselves say 44PSI. pretty big difference, but i understand that it's different for every car and so that's why there's the sticker on the inside of the door to tell me what's best for my model.

i'm confused by the big difference in the gap there, but also about what the tire's were at. the front two were in the 35ish range while the back ones were in the 40ish range. and i have no idea what they were when i brought the car home 7 days ago but it seems like that's a wide range in difference too. And we havent had any extreme temp changes in the last 7 days either.

i might just take it in, but thought i'd see what you guys had to say. Also, it's a RAV4, so a small SUV in case that helps.

thx!

For correct tire pressure, consult the manufacturer of the tires. For radial tires there is a fairly narrow range that is best. The tire manufacturer is the expert and the one responsible for the tires and their performance. Check with a dealer of that brand or call / go to the web site of the tire manufacturer. There is no way that 32 psi and 44 psi are both within recommended operating range for your tires.

**ruxCYtable** · 03-16-2010, 06:25 PM

Originally Posted by swammi

For correct tire pressure, consult the manufacturer of the tires. For radial tires there is a fairly narrow range that is best. The tire manufacturer is the expert and the one responsible for the tires and their performance. Check with a dealer of that brand or call / go to the web site of the tire manufacturer. There is no way that 32 psi and 44 psi are both within recommended operating range for your tires.

Incorrect. You do NOT consult the tire manufacturer. They only give the max pressure. They will refer you back to the manufacturer of your vehicle for the proper tire pressure which takes into account the weight of the vehicle and suspension setup. Go by the placard inside the door of your vehicle or the owner's manual, period. Even the tire manufacturer would tell you this if you contacted them.

**iowaboy** · 03-16-2010, 06:39 PM

Originally Posted by GoShow97

If I'm going on a road trip I'll inflate the tires to max pressure -44 psi - to help with gas milage. Other wise I'll bleed them down to 35 for around town to help with road complience. The trailer and motor home I'll inflate to max pressure. Supposidly on the commercial type tires for trailers you can even go 5 above max pressure. I just make sure I keep them to max. I also carry a pressure guage with me all the time. Inflation pressure is critical for tire life and performance.

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The fuel mileage differece between say 35 and 44 is miniscule at best. You'd be better to wax your car for the difference. During the summer tires will get hot at highway speeds anyway. having them at 44 and having it 90 degrees on the interstate at 75 hell, they'll be up around 60. Good luck with that.

If they are rated at 44 max, run the fronts at 36-38 and the backs 32-34. It will ride and operated great. IB

**ruxCYtable** · 03-16-2010, 06:50 PM

Originally Posted by besserheimerphat

The number on the door frame sticker is the car manufacturer's recommendation for the stock tires, based on a combination of ride, handling and mpg. If you are running the same make/model of tire as the vehicle was sold with new, then the door sticker is what you should probably run. Understand that higher pressure would yeild higher mpgs and potentially better handling at the expense of ride comfort. Lower pressure would give the opposite - worse handling and mpg with smoother ride.

If you are running tires other than the make/model the vehicle came with, you are kinda on your own. The number on the sidewall is the max you should put in the tire. Running right at that number should be okay, assuming your tire pressure gauge is accurate. If I didn't have a calibrated tire pressure gauge, I'd probably put them around 90% of the max pressure. Fortunately I've got access to highly accurate pressure calibration systems, so I can accurately fill my tires to within a half psi of the max rating because I've calibrated my gauge.

You are safe to run at the max pressure. The max pressure takes into account the dynamic forces that your tires see at temperature extremes, at the max rated speed and at high g-loads.

This is also a myth. It doesn't matter stock tires vs. after market, or make/model/brand of tire. Every model of new car might come with 5-6 different brands/models of OEM tires. They don't each come with a different recommended tire pressure. The tire pressure recommended by the CAR maker is what the engineers have calculated will provide the best balance of ride, handling, mileage, wear and other factors. It is not specific to any brand of tire.