How accurate are the HHR's tiree pressure sensors? My manual guage is telling me 30 psi but the DIC display is reading 27 to 29 psi. Which do I trust???

I haven't got an answer for you but I bought a digital reader and found 3-4 pound difference...

JIm

The service dept. told me to expect a (+/-) 3 pound differential..

Firestone recommends 30 psi, the dealer recommends 33 psi, and
Discount Tire recommends 35 psi....

Mine are inflated to 35 psi.....

Cajun

My TPS is 1-2 psi lower than the dial gauge I use. I trust the dial.

The service dept. told me to expect a (+/-) 3 pound differential..

Firestone recommends 30 psi, the dealer recommends 33 psi, and
Discount Tire recommends 35 psi....

Mine are inflated to 35 psi.....

Cajun

17'' that came from the factory are 35 psi cold. Sticker on the door pillar has the correct pressure for the factory installed tires for anyone else who wants to know what "theirs" should be.

The 16" affinity recommend 30psi. Dealer told me 32. I went 33 just because Obama said so. lol.

Good for him. I didn't know you knew him. Wow, you sure are lucky:bow: :eek: :lol: :nuts: :barf:

Seriously with my calabrated gauge the pressures on the HHR and my wifes STS are the same as long as the gauge reads on the high side of the mark but below the next one. So less than a lb. difference.
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The 16" affinity recommend 30psi. Dealer told me 32. I went 33 just because Obama said so. lol.

I"ve been having touble keeping one rim at 30 on my SS. Took it to the Dealer to find the leak and they couldn't. But I did notice that they jacked the pressure up to 36. Don' t know if this will help the leak situation.

JIm

Also with some of us here how accurate is the gauges we are using?

Cheap ones are not always too accurate even in Digital.

I have a good Circle Track gauge that is on the money and it shows my TPM's to be 0-2 PSI off.

I worked with Ammco/Coats when tire pressure monitoring first came on the market. I wrote several manuals dealing with tire changing, balancing, etc. on cars with TPMS installed. At the time, no manufacturer was including it on the vehicle, they were only aftermarket. Anyway, one of the things we covered in our manuals was that the system was best for monitoring the change in tire pressure and not necessarily the "actual" pressure in the tires. That was the point of the original systems: to help you monitor the pressure in your tires so that you were aware of any loss in pressure.

I've been flamed on this before, but trust me, I worked in this field at the beginning.

The current systems are far superior to those first ones, but the fact still remains that you should only rely on them to notify you of a tire going soft and not to give you "accurate" psi readings in your tires. Always use a good, reliable gauge to check the pressures yourself and maintain proper pressures.

Just my 2 cents. Flame resistant suit now engaged.

I worked with Ammco/Coats when tire pressure monitoring first came on the market. I wrote several manuals dealing with tire changing, balancing, etc. on cars with TPMS installed. At the time, no manufacturer was including it on the vehicle, they were only aftermarket. Anyway, one of the things we covered in our manuals was that the system was best for monitoring the change in tire pressure and not necessarily the "actual" pressure in the tires. That was the point of the original systems: to help you monitor the pressure in your tires so that you were aware of any loss in pressure.

I've been flamed on this before, but trust me, I worked in this field at the beginning.

The current systems are far superior to those first ones, but the fact still remains that you should only rely on them to notify you of a tire going soft and not to give you "accurate" psi readings in your tires. Always use a good, reliable gauge to check the pressures yourself and maintain proper pressures.

Just my 2 cents. Flame resistant suit now engaged.

i would have to agree........ i was driving my wifes monte carlo...... and i must have ran over something on the road and the tire sensor picked up the pressure difference...... i made it to the dealership where it went flat, they fixed it then i was on my way.... if the monte hadnt had the sensor i would have had a flat somewhere else......

i would tend to agree that its there just to monitor .....

the more they are inflated
the less struggle it takes to rotate
so better mpg with the higher number
i keep mine 33-35

the more they are inflated
the less struggle it takes to rotate
so better mpg with the higher number
i keep mine 33-35

True. Trade off here is that over inflated tires wear unevenly, just as under inflated tires do. Of course, the wear-out is different for the two, but it does shorten the effective life of the tire. Maintaining tire pressure at the tire manufacturers recommended pressure is the best way to get maximum tread life (depending, of course, on other factors such as proper balance, alignment and other related items).

The service dept. told me to expect a (+/-) 3 pound differential..

Firestone recommends 30 psi, the dealer recommends 33 psi, and
Discount Tire recommends 35 psi....

Mine are inflated to 35 psi.....

Cajun

I go by what GM says. Correct pressures are on a yellow label located on the drivers door jam.

True. Trade off here is that over inflated tires wear unevenly, just as under inflated tires do. Of course, the wear-out is different for the two, but it does shorten the effective life of the tire. Maintaining tire pressure at the tire manufacturers recommended pressure is the best way to get maximum tread life (depending, of course, on other factors such as proper balance, alignment and other related items).

Just curious how overinflated (35psi) tires would have uneven wear when the tire manufacture rates them up to 44psi? I know GM takes many things into account, including tire wear, but do you really think higher inflation (below tire manufactures rated max) will wear unevenly? I know the ride suffers.

I go by what GM says. Correct pressures are on a yellow label located on the drivers door jam.

Yup, there is a reason they post certain PSI's for their cars.

I was getting real big differences in my stick qauges and my DIC, ended up getting a new digital air gauge, and was able to dial in the pressures right on the money (granted , the accuracy of the new one could be off a lil also)I compared my new gauge, the DIC and the couple of stick type gauges i had and end resultas was: the stick ones were WAY off(tires woulda been underinflated, one gauge was 8-10 PSI over what it really was! :eek: )
After all this, i realized one of the stick gauges was prob 25 yrs old! :red: :cussing: :roflol: :thumbsdow (pitched them inna heartbeat ;) )

Just curious how overinflated (35psi) tires would have uneven wear when the tire manufacture rates them up to 44psi?

I'd think that was the max the tire could handle, not necessarily a high end of recommended inflation.

Last set of tires i had installed on the truck, i noticed i had a tire that would go low(flat) in a 1/2 days time. during the couple of times to the tire dealer to get this taken care of (new tire), i was told that "someone" had put, or left , almost 50 PSI in the 4 tires(prob forgot to let out the air after setting the bead or something, or mebbe someone there had a way off gauge). Either way it rode a LOT nicer after they set the pressure to the sticker on the door.:lol:

I think it needs to be said.....

The MANUFACTURERS TIRE PRESSURE RECOMMENDATION (as ChevyMgr, states, found on the sticker on the drivers door sill) is best for the overall performance of the vehicle. This considers the weight of the vehicle, amoung other things, for the proper PSI. This will allow the greatest contact of the tire to the road surface for maximum braking efficiency. GM provides this recommendation through vehicle testing and is calculated with a nominal driver weight (some of you are weigh (spelling intended) over the NOMINAL), a full tank of gas and 25 pounds of miscellaneous gear. However, this may have changed.

Over inflation (which provides a slightly "higher" tire) will round the tire and minimize thread contact with the road.....higher pressure, rounder tires...less contact. Conversely reducing tire pressure causes cupped or concaved tread to road surface patterns. Thus, also reducing braking efficiency.

Understand of course, as your vehicle weight increases, do to passenger or material, there is a necessity to increase tire pressure, ACCORDINGLY.

The TIRE MANUFACTURERS RATING, located on the side of the tire, is based on several different vehicle applications, for the tire, and/or the increased content load of the specific vehicle.......in which case, the maximum should not be violated.

At least that is what was told to me by tire engineers when I worked for "The General".

It amazes me that owners will spend a thousand dollars to increase braking efficiency on new rotors and pads and then under or over inflate a tire which provides a negative dynamic. The new brake equipment is only as good as the critical contact to the road.

Thanks Snoopy, I didn't think that a tire mounting on the appropriate wheel inflated over the door label pressure, but under the tire manufacturers max would "round the tire". I guess that makes sense.

Soooooo, since I am usually in my car alone, should I be inflating the drivers side more than the passengers side:lol: Just kidding.

What about when you change tires and tire brands? Do you still use the door label, or what on the sidewall:confused:

Soooooo, since I am usually in my car alone, should I be inflating the drivers side more than the passengers side:lol: Just kidding.

Now that winter is approaching you do need to get all the summer air out of the tires and get winter air in there!

What about when you change tires and tire brands? Do you still use the door label, or what on the sidewall:confused:

No.

Now that winter is approaching you do need to get all the summer air out of the tires and get winter air in there!


No.

Oh, I just put my fall air in, I know most people don't bother and just go from winter to summer, but I am a fanatic :nuts:

No, which one?

I have to agree on the fact that this system is only there as a reference to let you know if a tire is getting low. My wife was 200 miles from home with our '08 and she saw that the DIC was showing one tire at 25 psi. Took it to a tire shop and they found 2 screws in the tire which they plugged. Without this system, I know she would never have known there was a problem until the tire was completely flat. I'm also glad she has the sense or curiousity to scroll through the info now and then.

Took my SS in because the damn wheels were leaking air.
They couldn't find a leak but boosted the PSI to 37. haven't leaked since.
What gives?

JIm