depends on the car. If I'm driving about town, somewhere just over the door sticker... on the other hand, if I'm hauling a load or there's more weight in the car - I'll inflate until I get reasonable handling but not more then max pressure.
Use the door pillar pressure. If you use the sidewall rating especially on a truck, you will notice the centers will veneually have no tread compared to the outer edges.
I start with the revommended preasure . This is 32 lb on my stuff .generally I'll run the front at 35 to keep the edges from prematurely wearing .Rears 32 . If I put a gat tire on a wide rim but still has a pretty good curbe to the side wall I lower it .
Generally Max rating pressure, but, will adjust down if tire wear indicates... rotate religiously and use a tread depth gauge for accuracy... I have to... 150 miles per day on the work commute...As Squirrel stated, Can't really follow the door recommendations while running anything other than factory rolling stock...
Patrick & Tammy - Long Haulin' 2008, 2009, 2010, 2011, 2012, 2014...Addicting isn't it...??
Since I don't understand very much about anything, this is a great question. I went and looked at the sidewall on Red's Conti Extreme Contact D/W's. It says never use more than 40 PSI to set the bead, and then inflate to the car manufacturer's recommendation (owner's manual, door panel).
I don''t get that. I would have thought for sure it would vary by the brand/type of tire construction. And then vary AGAIN by what you're doing with (to) it, like hauling, or in our case pounding the snot out of it on a road course.
FastEd here on BS fed me specific data on how to set the D/W's for a road course - 36 front, 33 rear, and check to see that they are not over 42 while stinking hot after a run. That was something he and his racing buddies worked out, and it works SO well. For THAT particular usage.
I typically go by the tag on the door.. now.. let us not forget that the ford explorer debacle/catastrophe/shenanigans all boiled down to the fact that ford wanted 26 lbs of air for a cushy ride...
I have lots of customers who max the tire by the sidewall data. " i get WAY better gas mileage with them maxed...."
is 3 extra mpg worth scalping a set of tires in half the tread life??
You know, in my 30 years of driving, I don't think I've ever looked for the OEM recommended for inflation pressures. Before this email, if you has asked me where to look for mfg. recommend inflation pressure, I would have said the owners manual. I forgot it was on the door (or glove box lid on older cars).
I've always started with max sidewall in the front and 4 psi lower in the back, and tuned by feel from there. Loaded trucks and Corvairs are a different story.
How many go by the pressure rated on the door pillar by the OEM of the vehicle?
How many simply inflate to the maximum rated on the sidewall of the tire?
The best way to determine the correct PSI is to contact the tire manufacturer. They'll want the factory recommended tire pressures loaded and unloaded for the original tires from the owner's manual (or door tag) and the size tire you will be using. They'll provide the correct tire pressures for unloaded and loaded. When I put big tires on my Dodge diesel PU the tire pressures that Discount Tire recommended were way off.
Last edited by dieselhead; September 7, 2017, 09:13 AM.
I've always started with max sidewall in the front and 4 psi lower in the back, and tuned by feel from there. Loaded trucks and Corvairs are a different story.
yup. i actually run 40psi in the front 205/70/15's on 15x5.5 rims
(even though it says max 37psi) and 30-35 in the rear 275/60/15's
on 15x9 rear rims (that tire says 40psi max but gets bouncy there)
because thats what the car "likes"--handles best there.
i daily drive my car on hawaiis HORRIBLE system of linked potholes
that they claim are roads. no problems in 3 years, so far......
I run a 10.5 inch tire on a 9 inch rim... when I ran the lower pressure as recommended, the edges wore badly... so, i run high enough to get a proper contact patch...
Patrick & Tammy - Long Haulin' 2008, 2009, 2010, 2011, 2012, 2014...Addicting isn't it...??
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