Well, down here in the Southeast, many would argue that fall arrives with the start of high school and college football, or a myriad of other cooler-season traditions. Actually, football now starts way early, in the heat of August. But, to me, fall truly arrives when tire pressures drop.

Over the past weekend, fall arrived. Or so I will proclaim. We had a 30°F temperature drop, and Saturday morning, as I headed out for my pre-daylight walk, all four tires had TPMS alerts.

Why must I notice? Well, if my family were a fleet, 50% of its drivers would never notice. My wife would say, “Isn’t that your job?” or, “You’re the one who works at a truck publication.”

My answer to that – yes, and yes. So, I started the weekend firing up the air compressor and getting each tire spot on, exactly to the proper PSI, even the spare tire on the back of my Jeep Wrangler. Yep, check the PSI on your spare. Mine was extremely low.

In the consumer automotive space, it is all too easy for people to see a TPMS low-pressure alert and simply think, “Oh, I’ll take care of that later; I’m not going that far.”

Well, I don’t think any fleet managers would look at it that way, and hopefully neither would their drivers.

I think back to a TPMS article I wrote back in April and the tire experts who took the time to be interviewed and share their knowledge. As I recall, each one stressed the problems that result from underinflation.

With that, let’s transition from talking about TPMS and underinflation to talking about how that relates to safety.

For that TPMS article, I asked the experts a simple question: ‘Which is more problematic, under- or over-inflation, when it comes to blowouts?’

“Underinflation is the leading cause of tire blowouts,” answered Jason R. Hendrix, manager of training – TPMS, Autel North America.

Jon Darab, director of operations and outreach for the Global Center for Automotive Performance Simulation within Virginia Tech Transportation Institute, also pointed out that typically underinflation is more likely to cause blowouts than overinflation.

NHTSA’s Viewpoint on Underinflation

The National Highway Traffic Safety Administration’s final rule (49 CFR Parts 571 and 585) that mandated installation of TPMS in light-duty vehicles states: “This final rule requires installation in all new light vehicles of a TPMS capable of detecting when one or more of the vehicle’s tires, up to all four tires, is 25% or more below the manufacturer’s recommended inflation pressure (placard pressure) or a minimum activation pressure specified in the standard, whichever is higher.”

That TPMS requirement became effective April 8, 2005. Safety-related data drove the requirement.

According to the NHTSA, as stated in the final rule, under-inflation of tires increases the likelihood of many different types of crashes, including those involving:

• Skidding and/or loss of control of the vehicle
• Hydroplaning
• Increases in stopping distance
• Flat tires and blowouts
• Overloading of the vehicle

So, TPMS was added to light-duty vehicles, but the intent behind that mandate matters to fleets with heavier, larger vehicles.

Basically, make sure your drivers watch for tire alerts on their TPMS or, better yet, make sure they periodically check tires to make sure they are properly inflated at the start of the day.