Discount Tire too much air pressure

This is the first forum. We'll figure out if we want more.

Moderators: Basement Paul, MostMint, Fred32v, ttamrettus, wxo

User avatar
wxo
Posts: 1131
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Discount Tire too much air pressure

Postby wxo » Tue Dec 04, 2018 7:21 am

Every time Randi returns from taking her 2007 Avalon to Discount Tire for her free tire rotation, I check the tire pressure. Over time I have noticed that they consistently set the tires at 4-5 lbs too high. The door sticker states 29 psi and they are always in the 34-35 range when she comes back. We like Discount Tire because they honor their appointment schedules and makes it easy for Randi to get in, get her tire service and get on her way. Maybe our resident tire professional can chime in and shed some light on this subject. I wonder if this over-pressure is something tires stores in general do to help wear tires faster. Has anyone else noticed a similar trend?

User avatar
MostMint
Posts: 1790
Joined: Thu Jul 21, 2005 12:11 pm
Location: planning a race

Re: Discount Tire too much air pressure

Postby MostMint » Wed Dec 05, 2018 12:08 am

My guess is they choose a standard pressure rather than have their techs try to know every tire pressure for every vehicle. My best guess is there were lawsuits filed somewhere in the past and the safe route is to overinflate. Or this may be left over from the pre TPMS days where overinflation meant the tires would go a lot longer before they needed air and were abused by a customer who was not maintaining the tires, or maybe it could be stats show many people ignore the dash lights and keep driving on underinflated tires. I am curious if they provided any rationale?

I have seen tires from my Firestone store similarly inflated as well.

I routinely run my tires about 4-6 PSI high which reduces rolling resistance. There are a lot of dynamics happening when you pressurize a tire, and I know that generally speaking I am reducing the contact patch just a bit in favor of the reduced rolling resistance. There is a possibility this could wear the center of the tire more I guess but I do not have enough empirical evidence to support that.

You might also ask yourself why did the manufacturer set the pressure so low? Lower pressure would make the tire softer and smooth out the ride a bit, which may be a consideration in your vehicle. Ford and Firestone had a big scrape up when Ford built a top heavy vehicle and recommended a tire pressure that was too low, generated heat and wrecked tires causing a flat and subsequent vehicle roll over. I would not recommend running the tires below the recommended pressure from the tire manufacturer regardless of what the vehicle manufacturer recommends. The tire should have a safe operating range marked on the side somewhere.

Random thought: The factory TPMS only senses low air pressure not high. If there was any significant correlation of tire failures to overinflation I would hope the system would be programmed for that too.

You are doing the right thing though checking and setting them to your preference because 1) no guarantees of consistency from the store and 2) you and your family are those riding on the tires, not the guy at the shop.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]

User avatar
GMJohnny
Posts: 878
Joined: Wed Feb 04, 2009 10:56 am
Location: Auburn Twp, Oh

Re: Discount Tire too much air pressure

Postby GMJohnny » Wed Dec 05, 2018 6:22 am

Our resident mechanic friend says always run your tires at least 5 lbs. over what the
manufacturer recommends. He said it keeps the tires more square and keeps you from
wearing out the outsides of the tires. Apparently, he sees a bunch of today's newer wider tires
that have a ton of wear on the outsides and the middle is still good when he removes them.
I tried his recommendation on the 442 and hated it. I could feel every pebble that was on
the road, so I went back to 32 psi. I do run mine a few pounds higher in the Regal and notice
treadwear very evenly on my OEM tires.

GM

User avatar
wxo
Posts: 1131
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: Discount Tire too much air pressure

Postby wxo » Wed Dec 05, 2018 6:55 am

Excellent answers, guys! That's the kind of feedback I was looking for. I had considered running them a few pounds higher than the manufacturer recommended, but I had always read that it was best to follow the door spec. Maybe that's old knowledge and my brain database needs to be updated. I'm going to bump them up a few pounds.

User avatar
Maverick
Posts: 1610
Joined: Sun Apr 26, 2009 6:29 pm
Location: Raleigh, NC

Re: Discount Tire too much air pressure

Postby Maverick » Wed Dec 05, 2018 10:55 am

My wife's XTS has recommended 35 PSI all around and often runs 2-3 lbs under that. I just replaced all the tires because they were warn more in the middle. I'll be checking tire wear to choose inflation pressure.

Actual results probably depend on driving habits, e.g., how aggressive you are in corners and how much Interstate driving you do with raised pressures.
Maverick

User avatar
MostMint
Posts: 1790
Joined: Thu Jul 21, 2005 12:11 pm
Location: planning a race

Re: Discount Tire too much air pressure

Postby MostMint » Sat Dec 08, 2018 8:49 pm

Maverick wrote:My wife's XTS has recommended 35 PSI all around and often runs 2-3 lbs under that. I just replaced all the tires because they were warn more in the middle. I'll be checking tire wear to choose inflation pressure.

Actual results probably depend on driving habits, e.g., how aggressive you are in corners and how much Interstate driving you do with raised pressures.

Also weight of the vehicle, rim width vs tire size will be factors in that wear pattern.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]


Return to “General Discussion”

Who is online

Users browsing this forum: Bing [Bot] and 7 guests