If you look at EPA fueleconomy.gov for 2002 vs. 2005 Beetle TDIs, you'll notice the "smog index" has improved from a 1 (bad) to 6 (average). Difference? New injectors for cleaner-burning. So YES diesels are improving... the claims are not empty.

After NOx filters are added in 2007, that number will probably jump to a 9 (above-average).



I suspect you've driven behind diesel cars, and not even realized it. That often happens to me, until I suddenly notice the "TDI" plaque. You can't tell the difference... there's no smoke or smell.

Also, gasoline cars can be pretty smelly. I was behind a gasser the other day that was blowing a bluish-purple smoke that smelled like a *skunk*. Ewwww!



And as for aging, gasoline cars age *faster*. Lifespan of a gasoline car is 250-300,000 miles typical. Lifespan of a diesel is 500-600,000 miles. Diesels are simpler (example: no ignition system), so there's less to go wrong. Diesels are built with stronger, thicker metals.

Gasoline cars age faster.

troy