Re: Trailer tire pressure.
Mark, From what you said about 12" size and smaller tires should be run at Max inflation is true, and I don't doubt it, I would run them that way also, but otherwise, I'll figure the maximum load, at maximum inflation, and divide by my load, then inflate to just what I need. That's usually the way I've always done it.
If each tire will hold 1500lbs max load, at 44lbs max inflation = 3000lbs @ 44lbs, and my total load is 1500lbs then I would inflate to 22 lbs per tire.
Or take my Tucson for example, 4 tires each 215/65/16" tire rated at 1653lbs and 44lbs Max X 4tires = 6612lbs
But, fully loaded weight 3500lbs + (5 people & gas) total about 1000lbs = is only 4500lbs, it works out to be 30lbs per tire as it says right on the sticker!
Even though, it's only my wife, & I, and a light load most of the time.
This post is rather long but I hope many of you out there take the time to read it. I don't pretend to be an expert on the subject. My understanding of the topic is garnered from years of interest in the subject of tires and pressures, reading a vast amount of information, and my own experiences.
I don't post very often, but felt compelled to do so in this thread. Mikdee, please understand I mean no disrespect or attack on you personally but running any tire at 22 pounds routinely, is absolutely "a blowout waiting to happen."
Remembering Ford/Firestone debacle, Ford was recommending just 26 pounds in the Firestone tires on Explorers here in the US. In South America they recommended a higher pressure. The lower pressure was to compensate for the harsher ride inherent in a truck at time when SUVs were just catching on and drivers were used to a more plush ride from the cars they were trading for their new SUVs.
Now heres the important point that you also touched on: the car manufacturer recommended pressure is a not a "fully loaded" pressure. It weighs several variables that have been mentioned in this thread, such as ride and tread life. The problem with Ford was that the 26 pounds they were recommending was for normal use, meaning just a driver and one passenger or so. The tires were blowing because 26 pounds might be just barely OK in an unloaded condition, but round up the troops for a trip to Costco with four or five passengers and cargo, and 26 pounds is a dangerously low pressure to be running. In that condition, the maximum pressure from the tire's sidewall, likely 35 or 44 psi is necessary for safety. As a result of the fallout from the tire problems Ford increased the recommended pressure for the Explorer to a safer level.
30 psi on your Tuscon seems low to me, but that pressure is the one Hyundai recommends for the exact tire they put on it at the factory. All tires are not created equal, just ask someone here about the difference between trailer tires and car tires. The OEM Tuscon tires might be tough tires with strong sidewalls that can deal with what I feel is a low pressure. In that case Hyundai probably knows better. But change that tire to a new one that is not the same tire as the OEM and it is a different story. How many of us have the factory tires on our trailers and other vehicles? I know I don't. Now we have to determine what the right pressure is with a different tire.
As for what I do, I have always run tires at or near the max pressure listed on the tire itself. A 44 psi tire I run at 40, a 35 I run at 35. I think on my truck running my 44psi Firestone Indy500's makes for too harsh a ride so I go with 40. That is in the face of Chevy recommending just 32. I have worn down many a set of tires bald, perfectly evenly, getting at least the warranted mileage out of them and sometimes drastically more. My wife's Mustang got around 55,000 miles out of a set of Goodyear Eagle GA's, at the max pressure. My last set of Firestones got about the same mileage at 40psi even though I drive like an idiot most of the time (that means going way to fast around corners mostly).
And finally everyone remember the pressures listed whether it be from the car, trailer or tire manufacturer is a COLD pressure. That means check them before driving more than a mile during a moderately temperate part of the day. That is not the coldest part nor the hottest part of the day. A tire is a pretty tough piece of equipment, full of steel belts and other fibers covered in a synthetic rubber that can take a helluva lot more than 44psi.
I tell everyone I know to start with the max tire pressure listed on the tire itself and reduce it a couple of pounds, if you must, to even out a too harsh ride. Over-inflation is going over the max pressure on the tire not the car placard. I hope you all made it to the end, as this officially qualifies as my longest internet post ever. Mikdee I hope you take no offense, and I would suggest running more pressure in your tires. But that is just my opinion. Thank you.
