GMC Acadia Forum banner
1 - 16 of 16 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Does anyone else experience issues with the tire pressure. When we get the diagnostic report we always have to fill the tires. Front passenger and rear driver sides will give one reading say 35, and the Front driver 34 and rear passenger will be 36. Husband checks pressure and sometimes it doesn’t change. TIA
 

·
Registered
Joined
·
1,704 Posts
How accurate is his tire gage?
Regardless, almost guaranteed you are not measuring at the same moment as they are taking the reading. Sunlight alone can adjust tire pressures. Do you generally park outside?
 

·
Super Moderator
Joined
·
22,619 Posts
Don't be concerned too much with the TPMS reading while you're driving around as tire pressures will vary. The OnStar report shouldn't be relied upon either as an indicator of potential tire pressure problems, especially if the tires haven't returned to ambient (or 'cold') conditions when the report is generated. Follow the owners manual procedure for filling tires to the correct (or personally desired) pressure. Always do it with an independent pressure gauge when the tires are 'cold' - as in before driving anywhere. Check cold tire pressures about once a month and when the seasons change.
 
  • Like
Reactions: Munchkin and Grantv

·
Registered
Joined
·
5 Posts
Discussion Starter · #4 ·
How accurate is his tire gage?
Regardless, almost guaranteed you are not measuring at the same moment as they are taking the reading. Sunlight alone can adjust tire pressures. Do you generally park outside?
It’s pretty new, so I would hope it is and he doesn’t buy cheap stuff. The car is kept in the garage.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #5 ·
Don't be concerned too much with the TPMS reading while you're driving around as tire pressures will vary. The OnStar report shouldn't be relied upon either as an indicator of potential tire pressure problems, especially if the tires haven't returned to ambient (or 'cold') conditions when the report is generated. Follow the owners manual procedure for filling tires to the correct (or personally desired) pressure. Always do it with an independent pressure gauge when the tires are 'cold' - as in before driving anywhere. Check cold tire pressures about once a month and when the seasons change.
Thank you. Will keep this in mind. I forgot to mention it’s a 2021 Acadia Denali, if that makes any difference to any of this.
 

·
Super Moderator
Joined
·
22,619 Posts
Tire air doesn't care about what make or model you drive. lol
 

·
Registered
Joined
·
1,704 Posts
I don't fret too much about 1# or even 2#
Check the display weekly, adjust when needed.
 

·
Registered
Joined
·
290 Posts
Yes tire pressure will vary a bit depending on the gauge.

I have also noted nearly every model has one tire that likes to be about one pound off. You can vary 3-4 pounds and it matters little.

Since you do have a 2021 it should have a fill alert. 0nce it hits the recommended pressure it should sound the horn. Have him read the owners manual on this, we just got our 2021 and I have not tried this feature yet To know how well it works.

Note too with winter coming pressures will drop soon with the colder weather. He may have to adjust pressure soon as depending where you live it can drop a good bit even with warm tires.
 

·
Registered
Joined
·
2,371 Posts
Thank you. Will keep this in mind. I forgot to mention it’s a 2021 Acadia Denali, if that makes any difference to any of this.
What you are seeing for initial tire pressure when you get the Onstar report is usually the tire pressure just a few moments after starting the Acadia. If it was after the Acadia was sitting all night or during the day, the Onstar takes it's monthly reading and the tire pressure hasn't stabilized yet.
I see this on the 3 GM vehicles we currently have also when we get the Onstar report.
The tire pressure may be 2 to 3 pounds off compared to real measure tire pressure.
After driving a few miles and the tires warm up then the tires usually read the same or no more than 1PSI difference between them.
Any difference is usually temporary or minimal. As long as you are not getting a "Low Tire Pressure" alert on the Acadia Driver Information Center all is well.
 

·
Registered
Joined
·
18 Posts
Does anyone else experience issues with the tire pressure. When we get the diagnostic report we always have to fill the tires. Front passenger and rear driver sides will give one reading say 35, and the Front driver 34 and rear passenger will be 36. Husband checks pressure and sometimes it doesn’t change. TIA
Keep in mind we are in change of seasons and done with the constant heat. As the car sits in cooler weather its natural for tire pressure to decrease slightly when the car isnt driven.. then rise again while driving long distances
 

·
Registered
Joined
·
1,575 Posts
Tire pressure changes with any change in temperature or any change in atmospheric pressure.

George
 

·
Super Moderator
Joined
·
22,619 Posts
Tire pressure changes with ... any change in atmospheric pressure.
Barometric fluctuations or differences in elevation would have negligible effect on tire pressures. That's not a great concern for the everyday driver. People should, however, be aware of average daily temperature during seasonal changes when adjusting tire pressures. This is why manufacturers recommend checking 'cold' tire pressures at least once each month.
 

·
Registered
Joined
·
2,371 Posts
In Autumn and Spring, I've always check tire pressures weekly as temperatures change. I've seen PSI drops or increases of 4 PSI or more at times from one day to the next depending on how much the the temperature change was.
 
  • Like
Reactions: Grantv

·
Registered
Joined
·
470 Posts
In Autumn and Spring, I've always check tire pressures weekly as temperatures change. I've seen PSI drops or increases of 4 PSI or more at times from one day to the next depending on how much the the temperature change was.
The 'rule of thumb' I go by and have found to be accurate pretty much regardless of tire size is a 1psi change for each 10°F change in temperature for vehicles in a garage or shaded from the sun. Being out of the sun is critical when checking or adjusting tire pressure as I've seen as much as a 4psi difference from the 'sun' side to the 'shade' side.
 

·
Registered
Joined
·
2,371 Posts
The 'rule of thumb' I go by and have found to be accurate pretty much regardless of tire size is a 1psi change for each 10°F change in temperature for vehicles in a garage or shaded from the sun. Being out of the sun is critical when checking or adjusting tire pressure as I've seen as much as a 4psi difference from the 'sun' side to the 'shade' side.
I agree. The PSI differences I posted were in garage usually over night when the temperature has dropped.
Regarding "sun side" PSI. . . . I sometimes check the DIC tire pressure reading after parking somewhere for and hour or more and one side is in shade. Indeed, there can be a 4PSI difference.

This time of year as daily temperatures drop if I add air to the tires and expect upcoming temperatures to drop the next day or week, I will over inflate 2 to 4 PSI so I don't have to add air again for awhile.
 

·
Super Moderator
Joined
·
22,619 Posts
Tire pressure fluctuates so much while driving that it's not worth the bother to check it so frequently. I've used the 'Ronco method' for years and it's worked out quite well - "Set it and forget it" until the next month, a MAJOR environmental change occurs, or I'm planning a road trip. Other than that, it's a waste of time. The TPMS is just another 'toy' to bend one's mind unnecessarily, IMO.
 
1 - 16 of 16 Posts
Top