Thread: Wow check your tire pressure when buying new!

Originally Posted by Bay Soul

California requires an auto repair business to check tire pressure & correct it to whatever psi the tire manufacturer put on the tire wall. I suspect it has more to do with the CA EPA & CARB trying to get the best time mileage possible as well as a safety factor. Service shops (including dealers) must write the psi they found on the work order so the customer knows.


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If California is making shops run the t.p. up to what's on the sidewall, then fools are writing the rules in California. The only time you run tires to the maximum allowable pressure marked on the tire sidewall is when the tire is carrying the maximum allowable load marked on the sidewall. I can guarantee you that a 2600 to 2700 lb. Soul is not even close to loading it's tires to the max. Tire pressures are set by the manufacturer of the vehicle according to the maximum vehicle weight as stated on the little sticker on the drivers door jam. If you drive around with the tires at the pressure indicated on the sidewall on a light vehicle like the Soul, you will wear the tires out down the middle of the tread, increase the harshness of the ride, which will in turn wear out suspension components prematurely, and reduce handling in inclement weather because you're driving on rubber rocks. Additionally, in hot weather the tire pressure will only go up from that max indicated pressure, which makes the tire far more susceptible to blowout at high speed.

I decided to buy a soul even without test driving it. When i got it from the dealer and was driving it for 10mins the ride wS so rough and felt regret that i didnt test drive it first. Thought it was normal. Then found out that the whels were all at 55psi.

50 PSI? Which model and what tires did you get?

My base 15" steelies only require 33 PSI, and they were at 35. Not a big deal for me since it's only +2 PSI, I just kept them at the current pressures

Originally Posted by thewerzinator

50 PSI? Which model and what tires did you get?

My base 15" steelies only require 33 PSI, and they were at 35. Not a big deal for me since it's only +2 PSI, I just kept them at the current pressures

yep mine were all at 50... I don't know it matters but I bought a ! with the 18 inch tires

I drove mine home from the dealer hearing *ting ting ting* instead of *tump tump tump*. It was only a few miles home and somehow I associated it with tire pressure. I got home and they were all 50+ psi. I let the dealer know (in a friendly way) to have their techs check tire pressure a little better. No harm, no foul. I caught it early.

Originally Posted by Bay Soul

California requires an auto repair business to check tire pressure & correct it to whatever psi the tire manufacturer put on the tire wall. I suspect it has more to do with the CA EPA & CARB trying to get the best time mileage possible as well as a safety factor. Service shops (including dealers) must write the psi they found on the work order so the customer knows.


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Shops here write the pressure too. BUT...I always check TP and wheel torque (torque wrench in both cars) because just because something's written down doesn't mean it's accurate.

I had the snows put on and the shop wrote "33" on the ticket. But my blasted TPMS light was on. Turns out they were carrying 30 lbs.

Originally Posted by The Old Grouch

If California is making shops run the t.p. up to what's on the sidewall, then fools are writing the rules in California. The only time you run tires to the maximum allowable pressure marked on the tire sidewall is when the tire is carrying the maximum allowable load marked on the sidewall. I can guarantee you that a 2600 to 2700 lb. Soul is not even close to loading it's tires to the max. Tire pressures are set by the manufacturer of the vehicle according to the maximum vehicle weight as stated on the little sticker on the drivers door jam. If you drive around with the tires at the pressure indicated on the sidewall on a light vehicle like the Soul, you will wear the tires out down the middle of the tread, increase the harshness of the ride, which will in turn wear out suspension components prematurely, and reduce handling in inclement weather because you're driving on rubber rocks. Additionally, in hot weather the tire pressure will only go up from that max indicated pressure, which makes the tire far more susceptible to blowout at high speed.

He probably meant doorjam/manufacturer's recommendation. Max is of course out there a bit, and that presure will be exceeded when the tires heat up.

Originally Posted by Bananabond

I decided to buy a soul even without test driving it. When i got it from the dealer and was driving it for 10mins the ride wS so rough and felt regret that i didnt test drive it first. Thought it was normal. Then found out that the whels were all at 55psi.

Guy in the prep shop needs to have a little further training. Only way to make that happen is talk to someone.

Originally Posted by thewerzinator

50 PSI? Which model and what tires did you get?

My base 15" steelies only require 33 PSI, and they were at 35. Not a big deal for me since it's only +2 PSI, I just kept them at the current pressures

Model and tire size doesn't matter. The problem is operator headspace at the air hose terminal.

Originally Posted by Zippydog

yep mine were all at 50... I don't know it matters but I bought a ! with the 18 inch tires

As far as the Nitro Theory goes.... "They" say that the nitrogen molecule is lager than the air molecule thus makes it harder for the tire to loose air pressure through the tire itself. however air is not a single compound....
Air is made up of a mixture of gases. The major component of air is nitrogen gas followed by oxygen

Name Chemical formula Percentage composition by volume
Nitrogen
N2
78.1 %
Oxygen
O2
20.9 %
Argon
Ar
0.9 %
Carbon dioxide
CO2
0.03 %
Neon
Ne
0.002 %
Helium
He
0.0005 %
Methane
CH4
0.0002 %
Krypton
Kr
0.0001 %
Hydrogen
H2
0.00005 %
Xenon
Xe
0.000009 %

FWIW, the reason many people find the tires at >40 psi when they take delivery is that Kia pumps them up to minimize the chance of damage to the tires (flat-spotting) during overseas shipping, sitting in inventory, etc.

The pre-delivery checklist includes checking tire pressure, but it is routinely ignored.

My 2011 was delivered to me (in December 2010) with 60 PSI in all four tires. It rode like crap and I couldn't figure out why. (I test drove one car, but bought another that had just come in -- guess it didin't make it throught the pre-delivery inspection.)

Anyway, they overfill them for ease of roll-on, roll-off in the ship containers.

Do you know how to reset that light if you add air and it does not go off? I am in Cincy and its very cold right now...what psi do you try to keep your tire at (when you feel like putting air in them....LOL)?