Congress Mandated a Tire Safety System That Warns You After the Damage Is Done. 600 People Die Every Year Anyway.

In 1998, strips of rubber started peeling off Firestone Wilderness AT tires on Ford Explorers. At highway speed, the SUVs would yaw, roll, and kill their occupants. Ford quietly replaced tires in Venezuela, Malaysia, and the Persian Gulf without telling American regulators.^[1] By the time NHTSA pried the data loose in 2000, 271 people were dead and more than 700 injured.^[2] Congress held hearings, looked horrified, and passed the TREAD Act that October, mandating tire pressure monitoring systems in every new passenger vehicle at roughly $48 per car. GAO estimated TPMS would save 124 lives per year.^[3]

Read the standard, though, and a problem emerges. FMVSS 138 requires the low-pressure warning to illuminate only when inflation drops to 25 percent below the manufacturer's recommended cold pressure^[4] — not 10 percent, not 15. If your placard says 35 psi, the light can legally stay dark until you hit 26 psi, at which point your sidewalls are already flexing hard enough to generate destructive heat and your stopping distance on wet pavement has grown by double digits.

How generous is that threshold? Ask the people who actually manufacture the rubber. The United States Tire Manufacturers Association, whose members include Goodyear, Cooper, and Bridgestone Americas, stated during National Tire Safety Week 2026 that TPMS "detects loss of inflation pressure and warns drivers when tires are 25% underinflated, which is often too late to prevent damage for some vehicles."^[5] The industry that makes the product is publicly saying the government's safety mandate triggers after the damage window has already opened.

NHTSA's own statistics confirm the shortfall. Nearly 11,000 tire-related crashes occur every year, and more than 600 are fatal.^[6] A pre-TPMS survey found one in four passenger cars and one in three light trucks driving on significantly underinflated tires, and eighty-five percent of drivers never check pressure manually.^[7][8] TPMS was supposed to compensate for that negligence, but instead it validates it: the warning stays dark, the driver assumes all four corners are fine, and the rubber cooks until it fails catastrophically at 70 miles per hour.

This week AAA projects a record 61.4 million Americans will drive 50-plus miles for the Fourth of July.^[5] Summer heat accelerates underinflation while highway speeds amplify the consequences, and the dashboard indicator Congress paid $771 million per year to deploy will spend most of the holiday weekend in its legally permitted silent mode.

Limitations: NHTSA's 600+ fatalities figure does not distinguish TPMS-equipped from non-equipped vehicles. The GAO's estimate assumed full fleet penetration now achieved, but current fatality counts include older cars without the system.

What you can do: Buy a $10 digital tire gauge and check all four tires once a month, cold, before driving. The TPMS light means your tire is already dangerously low. Consult the pressure on your driver's door jamb placard, not the maximum stamped on the sidewall, and if you are driving this weekend, check the spare too. NHTSA maintains a tire safety resource page with recall lookups.