tire preasue quesstion

[UnBeetable69]

my manual tells me the front tires should be at 33 psi and the rear at 41psi. on the tires there is text that reads "never exceed 40 psi when seat bead" is that for installing the tire on the rim? or not to exceed 40psi all together

[Smileybug]

That seems awfully high in general. Under your gas lid should have tire pressure ratings. I think mine says that it should be 27psi all around. I usually sit at 32ish psi and my tires are rated up to 44.

[Duffy]

I set my tire pressure to 33-34 psi on all.

[MiG]

I keep mine is at 35psi

[UnBeetable69]

i couldnt find it on my gas cap or door sill

[pstur1]

Originally Posted by UnBeetable69

i couldnt find it on my gas cap or door sill

Mine was not on the door sill (the part that is part of the body of the car), but on the driver’s door itself. I was also surprised that the back tires are supposed to have that much more air pressure in them as compared to the front. I guess this is definitely something to pay attention to when rotating the tires.

[MyOtherRidesAVette]

Originally Posted by UnBeetable69

my manual tells me the front tires should be at 33 psi and the rear at 41psi. on the tires there is text that reads "never exceed 40 psi when seat bead" is that for installing the tire on the rim? or not to exceed 40psi all together

I've never noticed that type of text on a tire, but installing would certainly be my guess. Does it say something about maximum psi? That wouldn't make any sense if the max tire pressure shown is in excess of that.

[MyOtherRidesAVette]

Originally Posted by Smileybug

That seems awfully high in general. Under your gas lid should have tire pressure ratings. I think mine says that it should be 27psi all around. I usually sit at 32ish psi and my tires are rated up to 44.

He says his OM says (one would simply mirror the other):

Originally Posted by UnBeetable69

my manual tells me the front tires should be at 33 psi and the rear at 41psi.

Originally Posted by Smileybug

I think mine says that it should be 27psi all around. I usually sit at 32ish psi

Why would you not run your tires at the recommended air pressure. This is the design pressure of the tires use on your vehicle for not just optimum tire wear, but proper performance of the suspension and steering, i.e. handling system, of your car. Over inflation is just as bad for wear and handling as under inflation. There are safety issues involved, especially handling on wet surfaces.

Why is it everybody seems to have better engineering abilities than the factory.

Originally Posted by Smileybug

my tires are rated up to 44.

What your tire is rated for has absolutely nothing to do with the proper inflation for your tires. Tires are designed to fit on and work with a multitude of vehicles. The proper air pressure revolves around the GVW of the vehicle. This same tire, I'm sure is the standard for many vehicles, some of which may be small trucks with load capacities. Examples of when the inflation of a tire would be increased are when the vehicle is towing and has the tongue weight of the trailer added to the rear load or when the cargo being hauled increases the weight on the rear axles.

It should also be noted that this in the recommended inflation for the tires (make-up and size) that are recommended for the vehicle. When you upgrade wheels and tires from a higher performance vehicle, you are typically not using them with the upgraded suspension system that was designed for their use on the"other" vehicle. If upgrading, for full performance and safety, you also have to upgrade everything else that is different on the "donor" vehicle.

MORAV

[MyOtherRidesAVette]

See also post above!

Originally Posted by pstur1

Mine was not on the door sill (the part that is part of the body of the car), but on the driver’s door itself. I was also surprised that the back tires are supposed to have that much more air pressure in them as compared to the front. I guess this is definitely something to pay attention to when rotating the tires.

That is the standard location! Should also give you the proper size tire and tire rating(s). I was surprised to hear Smileybugs was somewhere else.

As to front and rear tire pressure being different, that has probably become more the norm than the exception because of the "exoticness" of the steering and suspension systems. It also comes about from testing.

If you are running the specified size tires, run the recommended pressure, for the reasons noted in the post above.

MORAV

[hadda61beetle]

Originally Posted by pstur1

Mine was not on the door sill (the part that is part of the body of the car), but on the driver’s door itself. I was also surprised that the back tires are supposed to have that much more air pressure in them as compared to the front.

IF you have an NBC, the rear tire pressure will be more due to the weight from the electric motors for the top. also, always adhere to the tire pressures on the door jamb. They are there for a reason and they are specific for a reason. Go higher, wear out the tires quicker; go lower...creates a possible dangerous situation.

Just my .02

jerry

[Smileybug]

MORAV...I run a bit higher because I get better fuel economy. My tires lasted 5 years like that with no uneven wear...I had to replace them because they were starting to dry rot but still had plenty of tread left. I also got 37mpg on those tires at 32psi. I've yet to see that good if I run them lower. I just got them refilled at Discount Tire with 28psi so we'll see how well I do. I also know that the max rating has nothing to do with how much you fill them up I was making a statement that the 41psi seemed awfully high, when my performance tires were rated up to only 44psi. Seemed to be pushing the limits of the tire in my mind. I wouldn't want to run close to that max amount.

And my tire pressure rating is on the inside of my fuel door as well FWIW.

[MyOtherRidesAVette]

Tire life is affected by the air pressure, no question. As is fuel economy. I've never measured tire life in terms of years or months. It is also terribly related to the quality of the tire, the performance characteristics of the tire, steering and suspension maintenance, tire rotation, the way you drive and so on. Price of the tires do not always indicate life of the tires. I run Michelins ($$$$) on my non-performance vehicles and typically get 80k miles, with tread left. My Corvette on the other hand gets 20k to a set of high-end, quality, expensive, performance Goodyears. Btw - I have also never, ever, had a flat tire with a Michelin (1M miles plus)!

I believe you are getting better mileage and more life out of your tires at 32psi, I don't question or doubt that. How much more? And worth the trade-off? You should experience a much more comfortable ride and noticeably better handling in inclement weather (esp as relates to hydroplaning) at 27 lbs.

MORAV

[Smileybug]

I got over 40k on those tires but again, they had to be replaced because of the dry rot. Tread was only about halfway used and completely even. I liked the ride better at 30-32psi than I did with it lower. I had Hancook tires that the dealer put on (I didn't choose them). This go-round I got Kumhos. So far so good. Much better in the rain than those Hancooks ever were...and they were rated for rain performance! Never hydroplaned though.

[MyOtherRidesAVette]

Originally Posted by Smileybug

I got over 40k on those tires but again, they had to be replaced because of the dry rot. Tread was only about halfway used and completely even. I liked the ride better at 30-32psi than I did with it lower. I had Hancook tires that the dealer put on (I didn't choose them). This go-round I got Kumhos. So far so good. Much better in the rain than those Hancooks ever were...and they were rated for rain performance! Never hydroplaned though.

Probably not bad mileage, all considered. The dry rot thing mystifies me. But not much you can do about it other than find tires with a different rubber composite, I guess. The tire thing has become such a game, so many different "models" within one manufacturer, determined by want you want the tire to do and how long you want them to last.

And in thinking about your psi, and your limited mileage, most of your driving is city and your in a milder climate than I am in. Cold pressure is really just a guide line, i.e. 27 psi cold, on a black asphalt highway at 80 mph when the ambient temp is 100° and the pavement temp is probably 140° is probably a lot higher in hot psi than what you are running cold, if that makes any sense.

Glad you like the ride and the handling of your new shoes!

MORAV

[joemac]

My 2006 NBC shows on the door sill front 33 rear 41. I don't understand because the engine is in the front where the lower psi resides. Maybe they know something I don't. I'm just following the instructions.

Joemac

[memupp]

My 2008 NBC door jamb says 34/34. The main owner's manual says 34/34. The "supplemental manual" says 34/41. What's that about?

I just bought the car a few days ago and I checked the tire pressure as soon as I brought it home. All 4 tires are at 34 PSI. The tire sensor is fine with it - shouldn't I be?