Tire Pressure Help Needed

[twamd80driver]

On my 76 the door tag says 20lbs. in the front and 26lbs. in the back. Does that still work for todays modern tires?

Thanks!

 

[drags1998]

I would up-that some!!!! Try somewhere around 30-34 Lbs. It really depends on your style of driving and type of tires you have.

 

[Alan76]

I run 32lbs on mine works just fine handles well and get good gas mileage

 

[Stallion]

I run about 32 all around too. I wouldn't go much higher then that though.

 

[twamd80driver]

I am running Goodyears now, and am curious what types of changes in performance you get when you add or subtract tire pressure?

 

[Stallion]

Well I think the general rule of thumb is that the lower the tire pressure, the more tire on the ground, and the more traction. But there is happy medium between too little and too much.

 

[jason r. nugent]

tire pressure it is marked on the tire you should use it as a guide line any where between 26 psi and 40 psi depending on the weather conditions and tire makers seek information from tire seller for best determination of psi or a local car dealership

 

[lnirenberg]

I am running Goodyears now, and am curious what types of changes in performance you get when you add or subtract tire pressure?

Stallion is right, lower pressures, to a point, improve handling. Conversely, higher pressures, to a point, help gas mileage. On the low and high end different wear issues develop and at extremes, safety has to be considered. I have V rated tires on my car and I keep my cold pressure at around 30.

 

[GaryS]

Well I think the general rule of thumb is that the lower the tire pressure, the more tire on the ground, and the more traction. But there is happy medium between too little and too much.

I have read that the general rule of thumb is more pressure = more performance and fuel mileage and a worse ride. Less pressure = equals a better ride and lower mileage. I start at 30 psi and go from there. Use your other cars as a guide and you will see that the tire pressure from the manufacturer is around 30-32 psi. Never exceed the cold pressure as cast into the sidewall.
Gary

 

[Stallion]

Well less psi is lower milage because the lower the psi the smaller the circumference of the tire. Therefore same amount of revolutions = less miles = less mpg. That's my guess.

 

[Grizzly]

For what it's worth I asked the Goodyear engineers at the 50th Aniversary bash in Nashville about the the 225/70 Eagle GT+4's on my 67 and they recomended 28.

 

[JohnZ]

tire pressure it is marked on the tire you should use it as a guide line any where between 26 psi and 40 psi depending on the weather conditions and tire makers seek information from tire seller for best determination of psi or a local car dealership

The pressure molded into the tire sidewall is the MAXIMUM PERMISSIBLE INFLATION PRESSURE to avoid damage to the tire, not an operating pressure, which is dependent on the car it's mounted on. A good rule of thumb for radials is to start at 32 psi (cold) and adjust from there based on driving preferences and observed tread wear patterns.

 

[brusso]

On my 76 the door tag says 20lbs. in the front and 26lbs. in the back. Does that still work for todays modern tires?

Thanks!

No, unless you want to be another Ford Explorer flip over statistic. It looks like you've gotten some good numbers from people here. 30-34ish p.s.i. when cold.

 

[Stallion]

I thought those SUV flips came from overinflated tires. And blowouts came from underinflated ones. No?

 

[brusso]

I thought those SUV flips came from overinflated tires. And blowouts came from underinflated ones. No?

I thought that it went something like this. Low pressure cold = more side wall flex = hotter sidewalls = blow out = flip of SUV.

 

[The73vetteman]

Well less psi is lower milage because the lower the psi the smaller the circumference of the tire. Therefore same amount of revolutions = less miles = less mpg. That's my guess.

Circumference is going to change very little with lower inflation. The big factor here is rolling resistance. Basically, with a greater contact area (from lower pressure) the resistance increases dramatically. From (rusty) memory I think there's a square law at work here - something like 'drag increases with the square of contact area'.

John