Ok so I bought my Sonic in june of this year. I have put 1700 miles on it as of today. I just got an email from onstar saying my tire pressure was low. It says my tires are around 33 psi each. Now, this is my first real car, so I was wondering is this normal for tires to lose this much pressure of 3 months? Also do I have to pay for the dealership to fill them with nitrogen?
Tire pressure down?
- Thread starter Primenay
- Start date
CheapFuneral
New member
Most dealers will top off nitrogen free, if u got the car there or got a nitro service there.
mitdr774
also a dinner prick
Unless the tires were purged of all air before being filled with Nitrogen, I would not waste my time with having them "topped off" with nitrogen.
Your tires may have only been set to 32-34 PSI at the dealer. Many techs still follow the 32 PSI rule for cars. You may or may not have lost any pressure. Tire pressure can also vary a good amount depending on temperature.
Your tires may have only been set to 32-34 PSI at the dealer. Many techs still follow the 32 PSI rule for cars. You may or may not have lost any pressure. Tire pressure can also vary a good amount depending on temperature.
Moxie
New member
Onstar recommends the tires be set to 35 PSI. Recently when my two front tires were down to 32 PSI, the back were 38 PSI. Unless they filled my front and back differently at the dealer, my tires lost a lot of air quickly.
mitdr774
also a dinner prick
Just because it is recommended does not mean it was actually done. I have yet to follow the recommended pressure in my cars. I use what works best for me and is within the limits of the tires.
My tires pressures were off when i got my car. Not enough for the warning light, but enough that I took care of it at home. Based on how my tires hold air just fine, I have to assume the tech doing the PDI did not properly do the job. I would not be shocked since that dealer has already shown me that they cant even do a simple job like adjusting shift cables correctly.
My tires pressures were off when i got my car. Not enough for the warning light, but enough that I took care of it at home. Based on how my tires hold air just fine, I have to assume the tech doing the PDI did not properly do the job. I would not be shocked since that dealer has already shown me that they cant even do a simple job like adjusting shift cables correctly.
Moxie
New member
Good point. I tend to give the guys at the shop too much credit. I just like to pretend that they know everything about my specific car and will do everything exactly as recommended.
Back to the topic though. So in order to change to nitrogen, they would have to completely deflate the tires and then refill. I'm assuming that would cost some money.
Back to the topic though. So in order to change to nitrogen, they would have to completely deflate the tires and then refill. I'm assuming that would cost some money.
laborsmith
New member
If you look at the label on my door it says 35lbs.
If you look at the receipt from my last tire rotation: 38lbs.
I asked why and was told that 38lbs is now recommended.
The air in the tire is already something like 80% nitrogen but if that small amount worries you then by all means get it changed. As long as you forgive me for laughing at your action, all will be well. And even better if you can't.
Laborsmith
If you look at the receipt from my last tire rotation: 38lbs.
I asked why and was told that 38lbs is now recommended.
The air in the tire is already something like 80% nitrogen but if that small amount worries you then by all means get it changed. As long as you forgive me for laughing at your action, all will be well. And even better if you can't.
Laborsmith
sx sonic
New member
Oh Labor I always enjoy your post. Always full of win
OP there's a good chance your tires were not filled to the proper spec as Mitdr stated.
Your best bet would be to go in and have your tires inflated to spec (I think 38 psi is great and 35 is good) and then monitor them to ensure they stay within 1-2 psi of what they were inflated too.
Whether you choose to use nitrogen or not is your choice. Nitrogen's biggest advantage is the ability to maintain consistent pressure during temperature changes, this can be a big deal when winter comes and tire psi would normally drop, often times below recommended for people that ran 32 psi in the summer. Nitrogen will also hold pressure for longer periods of time than regular air, otherwise the two perform more or less identically.
CheapFuneral
New member
That's what the nitrogen service is dude.
As far as the pressure check it by hand because the sensors can vary some times. Don't be a nazi about it, as a former gm tech I can tell you some people will complain about the sensors not saying they are the same pressure. (In the buicks you can see all tire pressures from the display and old people have nothing better to do but complain.)
The idea of nitrogen is that you lose less because of temp changes in the tires. Air expands and contracts more so you lose more. You will still lose some nitro but less over time then air. You can mix regular air and nitro but once u do if you want to go back to nitro you have pay for the service (deflate and re inflate with nitro.)
CheapFuneral
New member
Actually this does happen. You can goto the dealer and watch, in fact our machine did it 2 times in a row to get as much air possible out of the mixtures. Legit dealers don't rip people off, but everyone thinks they do.
mitdr774
also a dinner prick
I have no desire to watch a tire jockey put nitrogen in my tire. I will use normal free air thank you. I have watched enough oil changes where tires were checked and topped off with shop air even though the green cap was on the stem. To me nitrogen inflation is just another gimmick to trick the average consumer into a false sense of security. They still loose air and go flat if you have other issues.
I used to work in GM dealers, I know how the dealer system works. I still go to the dealer for some parts and services, just not many if I have better options.
I used to work in GM dealers, I know how the dealer system works. I still go to the dealer for some parts and services, just not many if I have better options.
ScarabEpic22
Member
Nitrogen is pretty much a waste of $$. You *might* get some benefit, but as labor pointed out normal air is already 80+% nitrogen. Easy way for a dealer/shop to charge $10/tire or whatever, basically pure profit for them.
I wouldnt worry too much about it, Id be way more concerned and make sure your tires are properly inflated. The dealer filled mine 3 weeks ago to 35psi, Ill have to play with different pressure and see what feels best/nets best mpg/wear.
I wouldnt worry too much about it, Id be way more concerned and make sure your tires are properly inflated. The dealer filled mine 3 weeks ago to 35psi, Ill have to play with different pressure and see what feels best/nets best mpg/wear.
chivalryder
New member
Regardless of what you put in your tires, or whether or not you have the TPMS, you should manually check your tires once a month to ensure the pressure is where it should be. It's regular maintenance, just like you should check your oil every time you fill up the fuel tank (though almost nobody does that).
Says so right in the owner's manual! TPMS is just there in case one of your tires runs dangerously low without you noticing. It's not there to give accurate measurements day-in-day-out.
Oh, and IMO, Nitrogen is a waste of money. People seem to find new ways to take money from the ignorant every day. Just like water in plastic bottles!
Says so right in the owner's manual! TPMS is just there in case one of your tires runs dangerously low without you noticing. It's not there to give accurate measurements day-in-day-out.
Oh, and IMO, Nitrogen is a waste of money. People seem to find new ways to take money from the ignorant every day. Just like water in plastic bottles!
CheapFuneral
New member
Ill agree doing the service is a waste of money. But if u have it and its free to get it topped off why would you put air in instead? Yeah some techs will put air in nitro tires cause you have to specify that you want it. Most people couldn't careless like you guys and so most techs don't waste time filling with nitro cause they get paid nothing to do that.
Why waste the money you already have in it (the dealer adds that to the price of the car.) it's one thing if you get a flat then you fill with whatever is available, and its another if you just need to be topped off. I guess to each their own.
Why waste the money you already have in it (the dealer adds that to the price of the car.) it's one thing if you get a flat then you fill with whatever is available, and its another if you just need to be topped off. I guess to each their own.
sx sonic
New member
CheapFuneral that's a good point. Many dealerships and even some independent shops will do free nitrogen fills and top offs. In those cases there's not much reason not to get Nitrogen.
IMO the only time it's worth paying for is if your car sit's alot. Nitrogen's slower permeation thru rubber and more stability with temperature means you're more likely to come to a car that still has the proper tire pressure.
The biggest thing to realize is that while Nitrogen offers some very real advantages that it is not a law defying element that will never lose pressure. Some individuals will pitch Nitrogen as a service that will keep your tires permanently inflated to the proper pressure.
As evidence I've personally had Nitrogen filled tires that were below spec either because the psi hadn't been checked in a long time and gone low or the tire had a leak. When I informed the owners of this the common response was "it has Nitrogen how can it go low?" or " The shop must not have actually put nitrogen in!!!".
IMO the only time it's worth paying for is if your car sit's alot. Nitrogen's slower permeation thru rubber and more stability with temperature means you're more likely to come to a car that still has the proper tire pressure.
The biggest thing to realize is that while Nitrogen offers some very real advantages that it is not a law defying element that will never lose pressure. Some individuals will pitch Nitrogen as a service that will keep your tires permanently inflated to the proper pressure.
As evidence I've personally had Nitrogen filled tires that were below spec either because the psi hadn't been checked in a long time and gone low or the tire had a leak. When I informed the owners of this the common response was "it has Nitrogen how can it go low?" or " The shop must not have actually put nitrogen in!!!".
ColonelPanic
Banned
The guys at Costco used nitrogen when I had them put new tires on my wife's car. It was free, so I'm not complaining. But not something I would pay extra for. So far it hasn't required any topoffs, but when it does I'll just put "regular air" in it.
I'm one of those weirdos who checks tire pressure with a gauge once every couple weeks and even checks the oil at every fill (1x/week.) I refresh the OnStar app daily and check tire pressures between physical checks. It yields interesting results at times. I especially enjoyed the attached screenshot. 35 is OK here and here, but not there! Of course this was due to rounding - the "low 35" tire was 34.5. But it's still funny.
So far at 8k I've had to put air in them twice. The second time was merely because the car went into the dealer for a tire rotation with the proper 38 PSI and came out with 35 after the job was done.
I'm one of those weirdos who checks tire pressure with a gauge once every couple weeks and even checks the oil at every fill (1x/week.) I refresh the OnStar app daily and check tire pressures between physical checks. It yields interesting results at times. I especially enjoyed the attached screenshot. 35 is OK here and here, but not there! Of course this was due to rounding - the "low 35" tire was 34.5. But it's still funny.
So far at 8k I've had to put air in them twice. The second time was merely because the car went into the dealer for a tire rotation with the proper 38 PSI and came out with 35 after the job was done.
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