Car tire correct air pressure

[dan filipi]

Daughter has a 2014 Jetta, she took it in for service.
About a week later the low tire pressure light came on.

Pressures on 3 was about 28, right rear was 22.
Odd since tire MAX pressure says 51.

So I look on the door sticker and it says 33 manufacturer recommended MAX.
She looks on the service receipt and it says tires filled to manufacture spec of 33.

These are the stock tires that came on the car new btw.

So my question is, do we use the car manufacture spec or what it says on the tire?

I have always used the tire spec ignoring what the car spec says, afterall tires are designed for what they meet or need to meet, not what the car says.
On my service van the stock tires say 80 max. GM says 60 max.
If I ran these tires at 60 I would have overloaded and blown them long ago.

 

[ekvh]

My recent findings say go with what it says on the car. My gut says they could be a little more because they are wearing more on the edges. I believe most new tires say to follow car maker's recommended pressures, but I wonder if that isn't typical kya to remove themselves from liability.

 

[Mad Dog Tannen]

Manufacturer spec (on the door 33psi) definitely. Measure the pressure while they are cold. Do this for your bike as well (on the swingarm), it's even more crucial on motorcycles.

The wear on the edges is due to underinflation. 28 is low for most vehicles. 51 is waay to high and will cause problems. You could probably set the jettas to 35 or so to wear the middle a bit more and get better economy. Also a rotation and alignment are always good for tire wear as well.

 

[mcgovern61]

Recent issues with tires here revealed that we were using the tire spec and not the car spec on the door and I was having handling issues on the Elantra. Replaced the tires with exactly the same size recommended by Hyundai and to the door pressure settings and it drives like a whole new car!

 

[zman]

Took the dog for a walk and stopped by the tire depot and they confirmed to use the door sticker PSI when cold, rating is just the Max the tire will hold when hot.

 

[dan filipi]

mcgovern61 » 45 minutes ago[/url]":2hf4gaec]
Recent issues with tires here revealed that we were using the tire spec and not the car spec on the door and I was having handling issues on the Elantra. Replaced the tires with exactly the same size recommended by Hyundai and to the door pressure settings and it drives like a whole new car!

Was the tire spec pressure higher or lower than the car spec?

 

[Ansimp]

I never use less than 36 psi in any tire and have been doing that since the early 90s. I don't reconmend using the maximum pressure setting unless it is for extreme conditions ( Dans loaded van and only on the rear). Vehicle manufactures usually set a lower pressure than the tire manufactures as this contributes to a softer/smother ride. Lower profile tires require much higher pressures as there is little sidewall to absorb road impacts and under inflation can cause rim/wheel damage. Correct inflation will give you better tire wear/ mileage and provide safer handling also more air means less heating up of the tire :yes:

 

[Mad Dog Tannen]

dan filipi » Sat Mar 21, 2015 12:33 pm[/url]":2ukc7euz]

mcgovern61 » 45 minutes ago[/url]":2ukc7euz]
Recent issues with tires here revealed that we were using the tire spec and not the car spec on the door and I was having handling issues on the Elantra. Replaced the tires with exactly the same size recommended by Hyundai and to the door pressure settings and it drives like a whole new car!

Was the tire spec pressure higher or lower than the car spec?

No tire has a PSI spec, only a max pressure.

 

[mcgovern61]

dan filipi » Sat Mar 21, 2015 2:33 pm[/url]":cxogv0b1]

mcgovern61 » 45 minutes ago[/url]":cxogv0b1]
Recent issues with tires here revealed that we were using the tire spec and not the car spec on the door and I was having handling issues on the Elantra. Replaced the tires with exactly the same size recommended by Hyundai and to the door pressure settings and it drives like a whole new car!

Was the tire spec pressure higher or lower than the car spec?

As was already mentioned, the tire is only marked with the maximum pressure, but I was always running 32 PSI. The previous tires were made by Toyo and they were terrible! Slip all the time.

Replaced them with Maxxis tires and set them to the door pressure which was 31 PSI.

 

[sledge]

use what the Car says , because the Tire MFG have no idea what all kinds of cars or trucks their tire might be used on . the more the car weighs , the more air to carry it . the tire mfg only gives the Max pres. :laptop:

 

[Ansimp]

Just watch out using door pressure/ tire placard on older vehicles as tire technology has changed and in most cases new tires want more pressure.

 

[brianinpa]

Don't forget though that the tire manufactures and car manufacturers don't always agree: Firestone and Ford Explorers come to mind. Wasn’t Ford’s recommendation somewhere around 25 PSI for the Explorer?

 

[Ansimp]

brianinpa » Mon Mar 23, 2015 9:48 pm[/url]":xx5gu0kb]
Don't forget though that the tire manufactures and car manufacturers don't always agree: Firestone and Ford Explorers come to mind. Wasn’t Ford’s recommendation somewhere around 25 PSI for the Explorer?

My point exactly, Ford proved that their pressure was too low for the weight of the vehicle and the tires

 

[brianinpa]

Ansimp » Mon Mar 23, 2015 8:12 am[/url]":34qepkel]

brianinpa » Mon Mar 23, 2015 9:48 pm[/url]":34qepkel]
Don't forget though that the tire manufactures and car manufacturers don't always agree: Firestone and Ford Explorers come to mind. Wasn’t Ford’s recommendation somewhere around 25 PSI for the Explorer?

My point exactly, Ford proved that their pressure was too low for the weight of the vehicle and the tires

They proved it, but blamed it on Firestone... :shock:

 

[dan filipi]

sledge » Yesterday, 4:25 pm[/url]":28ycpv9j]
use what the Car says , because the Tire MFG have no idea what all kinds of cars or trucks their tire might be used on . the more the car weighs , the more air to carry it . the tire mfg only gives the Max pres. :laptop:

So far this explains best to me as it lines up with everything I've experienced with tires.

 

[slabghost]

agreed until it gets stupid. On any cage I won't go under 32 lb pressure. unless I'm drag racing and have the bead of the tires bolted to the rim.

 

[Omega Man]

slabghost » Mon Mar 23, 2015 6:48 am[/url]":34inf10x]
agreed until it gets stupid. On any cage I won't go under 32 lb pressure. unless I'm drag racing and have the bead of the tires bolted to the rim.

I used to 1/4 mile Street race on private roads in East Texas(56 Belair and 73 Camero), both very high performance and one night I used a friend's 9" slicks on the Camero. The air prensure was very low but Holy Moly how they grabbed. I almost wet myself.

 

[dan filipi]

I had a buddy with a fully loaded down service van like mine...running car tires.
No amount of air pressure would bring them up from looking like they were 1/2 flat lol.

 

[AApple]

Well now....this should REALLY get ya'll shakin yer haids!! :shock:

I'm a firm believer in using what the vehicle manufacturer recommends on air pressure. The vehicle was designed handle best, to be safe with that pressure.
The Firestone/Exploder fiasco was on BOTH parties, not just Ferd or Firestone. Firestone tires have been crap for MANY years.....recall after recall on them. Same can be said for Ferd.... :ahem: :hihihi:

 

[Ansimp]

Notice the total vehicle capacity!! I run over 20 psi in my shop/moving trolley tires!!
The dreaded driveway would eat tires with that low air pressure :yes: