Invest in a good tire pressure gauge

[Kia Stinger]

Why? Because too many mechanics don't bother using one - and it can be dangerous...

Click here if you'd like to buy it...

 

[Shieldzee]

This is the only one that I use and I have it in my car, my wife's car and my weekend toy car. Highly recommended. I agree that it is important. Tires for the GT RWD are between $260 and $290 US per wheel. And that does not include installation. Properly inflated tires will increase the life of the tires, make the car ride smoother and give better fuel consumption than improperly inflated tires.

 

[mldavis2]

Tire prices will likely come down after there are more cars out and more demand for that size. On my G8 GT, the tires were $250 each the first batch I bought, later came down to $210. New car, new tire, limited production....

 

[MarcMIA]

Why? Because too many mechanics don't bother using one - and it can be dangerous...

Click here if you'd like to buy it...

View attachment 2961

I notice that the interior/electronic tire pressure readout varies by several PSI from a manual tire gauge. Also, the tires were quite overinflated at delivery. Anyone else notice either of these?

 

[mldavis2]

I notice that the interior/electronic tire pressure readout varies by several PSI from a manual tire gauge. Also, the tires were quite overinflated at delivery. Anyone else notice either of these?

You have to be VERY careful when you get your car back from having it serviced. Speaking as a former GM-Subaru-BMW service manager many years ago, we always hired cheap, inexperienced labor for the grease rack and non-tech skills. Many of those guys (kids?) don't know the difference between a Yugo and a Ferrari. They think all tire pressures are the same - around 28psi. Always check after you get the car back, or request that they NOT adjust tire pressures on the service ticket. They will thank you for it, and you'll be happier.

Another thing you might want to watch is the readout on the dash. Some of these pressure valves are inexpensive and not well calibrated. You of course must stay within the allowable limits of the computer readout or it will badger you to death, but don't rely on that readout for actual pressure from a quality gauge. If the readouts are waaay off, take it back under warranty and demonstrate the difference.

 

[English D]

I notice that the interior/electronic tire pressure readout varies by several PSI from a manual tire gauge. Also, the tires were quite overinflated at delivery. Anyone else notice either of these?

Yep mine were at 52psi didn't know until a 1000 miles later had a wee chat with the service manager asking if they really did the PDI

 

[Irish]

Yeah I drove off the lot, not realizing that one of my tires was at 51psi, and the others were at 39psi. 260 miles later I realized it and fixed it.

 

[mldavis2]

Yeah I drove off the lot, not realizing that one of my tires was at 51psi, and the others were at 39psi. 260 miles later I realized it and fixed it.

And the tire pressure warning on the dash didn't light up??!! I guess it's a low-reference only?

 

[MarcMIA]

You have to be VERY careful when you get your car back from having it serviced. Speaking as a former GM-Subaru-BMW service manager many years ago, we always hired cheap, inexperienced labor for the grease rack and non-tech skills. Many of those guys (kids?) don't know the difference between a Yugo and a Ferrari. They think all tire pressures are the same - around 28psi. Always check after you get the car back, or request that they NOT adjust tire pressures on the service ticket. They will thank you for it, and you'll be happier.

Another thing you might want to watch is the readout on the dash. Some of these pressure valves are inexpensive and not well calibrated. You of course must stay within the allowable limits of the computer readout or it will badger you to death, but don't rely on that readout for actual pressure from a quality gauge. If the readouts are waaay off, take it back under warranty and demonstrate the difference.

On the bright side, I will say that they installed the wheel locks in front of me (the car was on the showroom floor) at delivery. They had a torque wrench. I asked them what they were torqueing it to. I checked the owner's manual and they did it correctly.

 

[Irish]

And the tire pressure warning on the dash didn't light up??!! I guess it's a low-reference only?

No there was no warning light. I assume your right that it only lights up for low pressure

 

[EchoesMyron]

Yes, it will only notify you if the pressure is low.

Be aware that pressure changes greatly with temperature and driving the car increases tire temperature and pressures.

You should only check and adjust tire pressure after the car has sat for at least several hours and not directly in the sun.

Only ever inflate the tires to the pressures given on the sticker on the driver's door jamb and NEVER to the pressure on the sidewall.

If you install a different size tire than what is on the door sticker, then the pressure will be different. The required tire pressure is a function of the volume of the tire and the amount of weight it is carrying. Increasing volume reduces the pressure required to support a given amount of weight, reducing the volume increases the pressure required. So if you went to a lower volume, lower profile tire, your pressure requirements would go up assuming the tire is supporting the same amount of weight.

With all of that being said, I have found the TPMS (tire pressure monitoring system) to be very accurate on all of the cars that I've had with it.

I aired up my Stinger tires and checked with a quality gauge and the TPMS readout on the dash exactly matched the gauge with the tires at 'cold' (undriven) temperatures. pressures can rise quite a bit (5-7psi or more) during driving and on a cold day they will be lower...how low depends on how cold it is. I set my pressures to 36F and 39R for my 18" all seasons the other day when it was 50 degrees and today when it was 20 degrees, they were at 33F and 36R when I started driving. By the time I got home, they were up to 38F and 41R.

 

[mldavis2]

That is pretty much what I found on my G8, @EchoesMyron. Very accurate on the dash, IF checked cold in the shade. But I never use the dash readings to check tire pressure, either.

 

[Ozstung]

I notice that the interior/electronic tire pressure readout varies by several PSI from a manual tire gauge. Also, the tires were quite overinflated at delivery. Anyone else notice either of these?

I noticed this when i checked the pressures after a week. 50psi allround. My local tyre guy told me car manufacturers do this on purpose for the long trip on the boat. They assume normally the pressures will have dropped by time of sale.

This now explains why some guys on the forum were complaining about excessive early wear. Have read on the gt2 that fronts should be 36 and rears 38.

 

[AV8R]

Bought one on eBay just now! $11

 

[CDv6]

This now explains why some guys on the forum were complaining about excessive early wear. Have read on the gt2 that fronts should be 36 and rears 38.

It's actually the reverse of that in the US, and only for the AWD 19s. Check your own sticker and country manual, of course, but the US manual lists it this way:

18" (presumably applies to Base, Premium, or GT/1/2 w/AS)
normal load (max 3 people): 36 front, 39 rear
max load, or over 100mph: 38 front, 39 rear

19" RWD
normal load (max 3 people): 36 front, 36 rear
max load, or over 100mph: 38 front, 39 rear

19" AWD
normal load (max 3 people): 38 front, 36 rear
max load, or over 100mph: 38 front, 39 rear
​

The single-page chart is on p8-4. There are also images of the three sticker types on p5-145, although it doesn't identify which sticker applies to which model (hint: it's the same order as I listed above).