200,000 mile cars? Thank (in part) the EPA

The New York Times over the weekend had a story about how Americans are holding on to their cars longer. As the Times explains, 200,000 miles is the new 100,000 miles – the point at which a car’s reliability becomes doubtful.

What’s all the more remarkable about this is that cars require much less routine maintenance than they used to. While Grandpa may insist otherwise, modern automobiles are simply built much better now than they were in the old days.

Part of this is because the market rewards higher quality – there’s a reason cars with reputations for longevity (Ford pickups, Toyota Camrys) are consistently among the best-sellers.

But as the Times points out, there’s another reason our cars are running longer: Stricter air-quality rules are forcing automakers to build better engines:

“The California Air Resources Board and the E.P.A. have been very focused on making sure that catalytic converters perform within 96 percent of their original capability at 100,000 miles,” said Jagadish Sorab, technical leader for engine design at Ford Motor. “Because of this, we needed to reduce the amount of oil being used by the engine to reduce the oil reaching the catalysts.
“Fifteen years ago, piston rings would show perhaps 50 microns of wear over the useful life of a vehicle,” Mr. Sorab said, referring to the engine part responsible for sealing combustion in the cylinder. “Today, it is less than 10 microns. As a benchmark, a human hair is 200 microns thick.
“Materials are much better,” Mr. Sorab continued. “We can use very durable, diamondlike carbon finishes to prevent wear. We have tested our newest breed of EcoBoost engines, in our F-150 pickup, for 250,000 miles. When we tear the engines down, we cannot see any evidence of wear.”