Stupid tire pressure question - Follow the label?
- Thread starter JeffKeryk
- Start date
No stupid questions, only questionable answers, wmao... For many years I've always gone slightly over the door label recommendation and never had any issues with abnormal wear, etc. My ride specs 35 for F/R since it's driver selectable AWD if needed and I dial that in to 36.25 @ 70 F ambient in shade. Then I check/adjust twice daily to keep things really dialed in. JK of course, but I do check psi/adjust if necessary at least 2-3x monthly, especially if large changes in weather roll in to stay.
From what I saw online the rec tire pressure on the earlier smart fortwo was 26-29 front, 32-36 rear psig
Maybe it was 199kPa and Matt saw it as 19.
O.K. - I hate this saying but - "Picture or it didn't happen!
OVERKILL
$100 Site Donor 2021
Only car I could find with a quick google that spec'd 19psi was the original VW Beetle and the sizes he mentioned appear to be commonly used on it? But as I noted, that car only weighs 1,700lbs.
My ex did have one of those and it was a solid, but tiny ride. Since it had no usable room for a spare I came up with a repair kit for her to keep onboard. Consisted of a piece of bubble gum to patch any leaks and a straw to inflate it, lmaoa...
manicrodder
$50 site donor 2022
We have the top line "X" with the 18" wheels but the standard 17" specs 35 psi. I tried 35 but 38 is better at least to me. I do hear what you are saying.
I go by the tire sidewall. Once the factory tires wear out the trucks and SUVs get E load rated tires, usually run the 5 Lbs under max, which is usually a good deal higher than the TPMS is set for.
On every vehicle I maintain (up to large crossovers or small SUVs) I do 40 PSI. If it's a low profile tire (50-sidewall or below) I do 35 PSI, unless the door sticker says higher. On full size SUV I do the door sticker +5psi, and then lower to 12-15psi for sand, or 20-25psi for long gravel washboard roads or light forest trails. Wear is always even (obviously aside from failed suspension components once in a while).
Even my Honda Ruckus 49CC scooter has 35psi in front and 40psi in the rear now. Recommended is 25psi, but at that level tires look flat-ish...
P.S. Yes, I know that 50-sidewall is not a size, but a relation of height to the width of the tire. But honestly in general: anything below 50 is considered low profile regardless of how wide the tire is.
Even my Honda Ruckus 49CC scooter has 35psi in front and 40psi in the rear now. Recommended is 25psi, but at that level tires look flat-ish...
P.S. Yes, I know that 50-sidewall is not a size, but a relation of height to the width of the tire. But honestly in general: anything below 50 is considered low profile regardless of how wide the tire is.
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I would like to see the actual door tag from the member with the 19psi pressure" Did we consider it may have been a miss printed tag? If so the tag itself may be something of a novelty to remove and keep?
Oh you will like one of my 1960 MGA weight wet is 1750lbs.
*It also has well over 500whp... now maybe if running slicks I would run 7-12lbs psi but on street tread 32-36psi cold.
*The other I never weight but I guess based on the changes I made that it was close to 2200 maybe 2300lbs but it only had est. 350whp
*blown SM CH nash 5speed,9 inch 5.14:1
*sm Ford C6 9inch 3.73:1
Interesting study and report!
As a personal rule I normally don't go hunting for internet information but in this case reading this and sharing it my put a little better perspective on why you use the factory recommended tire pressures?
As a personal rule I normally don't go hunting for internet information but in this case reading this and sharing it my put a little better perspective on why you use the factory recommended tire pressures?
- Joined
- Jun 13, 2013
- Messages
- 3,084
My other car is a 2002 Saturn SL2, with a manual tranemission, and 5th gear swap…
The .730 gear was replaced with a .605…
Dropped the RPM’s by 1000,…
Car is used for highway driving, the Smart is a grocery getter and errand runner…
TES-295 in the transmission instead of Dexron III…
Mobil 1 ESP 0W-30 in the oil pan, 44 MPG…
The .730 gear was replaced with a .605…
Dropped the RPM’s by 1000,…
Car is used for highway driving, the Smart is a grocery getter and errand runner…
TES-295 in the transmission instead of Dexron III…
Mobil 1 ESP 0W-30 in the oil pan, 44 MPG…
Last edited:
- Joined
- Jun 13, 2013
- Messages
- 3,084
I have gone through about five of these Slime tire gauges
I currently use this one and am happy…
I currently use this one and am happy…
- Joined
- Jun 13, 2013
- Messages
- 3,084
Be warned, the latest Slime inflator has a screw cap on the end…
shop.slime.com
You need an adapter to make it a lever style
shop.slime.com
12V Digital Tire Inflator
Slime's 12V Digital Tire Inflator is a compact, every day tire inflator that gets the job done. Nothing fancy, just a reliable, durable tire inflator. Inflates a standard mid-sized car tire in 6 minutes 12-volt accessory power Easy to read digital display, 0-99 psi Bright and long-lasting LED...
shop.slime.com
You need an adapter to make it a lever style
Tire Inflator Hose Adapter
Convert your tire inflator hose's twist-on connection to an easy press Hammerhead connection. Equipped with a snap-on connector, you can now quickly connect to your tire valve stem for a speedier inflation experience. Converts twist-on inflator hoses to press-on inflator hoses Easier to connect...
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OVERKILL
$100 Site Donor 2021
A 2002 SL2 should be 30/26 (F/R). In fact, you replied in that thread (with a bizarre compensation formula) that I found where multiple people confirmed that those were the placard pressures. Where is the 19psi coming from?
The old bias ply tires were more sensitive to pressure and tire wear. They would get real high in the middle with pressure. The radial ply stuff reacts differently with regards to pressure.
Being old I still try to compensate for tire wear with pressure. Hasn't
worked yet..
Being old I still try to compensate for tire wear with pressure. Hasn't
worked yet..
So your saying you run 75 psi? I can only imagine how that must feel, my Sierra calls for 50 psi and that is one bouncy ride in the rear, I have them at 45 psi which smooths it out some.
Tires are Cooper AT3 LT225/75R16
Should have said "D" tires, not E
Zee09
$200 Site Donor 2023
Usually I go a few pounds under as my hybrid at 38 Psi rides harsh at that setting.
My one car is actually too heavy for the tire specified by the 50/50 rule and at OEM pressures blows sidewalls constantly (as experienced by thousands of owners)
Tires don’t carry their maximum load until around the rated pressure on the tire, if your actual weight of the vehicle is much over 50% of the rated weight for the tires installed
your tire pressure has to be near the PSI rating printed on the tire for best life.
If your vehicles weight is near 80% you need it inflated at sidewall max.
One old truck I had listed different pressures on the door jam based on the amount of weight you were carrying, antique trailers sometimes listed this as well.
My experience with old 2wd pickups and suburbans was that it was best to keep the tires fully inflated because of the amount of weight I carried
Tires don’t carry their maximum load until around the rated pressure on the tire, if your actual weight of the vehicle is much over 50% of the rated weight for the tires installed
your tire pressure has to be near the PSI rating printed on the tire for best life.
If your vehicles weight is near 80% you need it inflated at sidewall max.
One old truck I had listed different pressures on the door jam based on the amount of weight you were carrying, antique trailers sometimes listed this as well.
My experience with old 2wd pickups and suburbans was that it was best to keep the tires fully inflated because of the amount of weight I carried
Matt, we need a photo of your vehicle load and tire pressure label on your door jamb.
Nowhere online do we see 19psig for a smart fortwo; I see 199kPa though.
You are not hitting those "gummies" again before posting?
Those are for special times