The Best Darn Diesel We'll Never Drive GM's new Ecotec diesels aremarvelous. Why won't it bring them Stateside?

General Motors Corp. and its Adam Opel AG division were kind enough to recently jet a few U.S. motoring journalists to Germany. The reason? To test engines the States won't get.

The engines are GM's all-new Ecotec turbodiesels, in 4-cyl. 2L and 2.2L flavors. The Ecotec range, claims GM, are the first production diesels to exploit both direct (in-cylinder) fuel injection (DI) and 4-valve-per-cylinder technology. The Ecotecs are by almost any standard beyond reproach. Why U.S. journalists were ferried over the Pond to drive them - when North American sales aren't a part of the plan - is a bit more nebulous.

First, the engines: The 2L Ecotec is a light-pressure turbodiesel that makes a respectable (for European driving styles) 82 hp. The "high-charge" 2L Ecotec uses the same AlliedSignal Garret turbocharger, but produces 100 hp. The high-charge 2.2L version develops 115 hp.

As with most of the new generation of DI turbodiesels, the horses aren't really the story - it's the torque. And like most of the DI automotive turbodiesels we've experienced, the Ecotec pulls like the proverbial freight train. There's a solid 136 ft.-lbs. (185 Nm) of torque from the light-pressure 2L unit, 151 ft.-lbs. (205 Nm) from the high-charge 2L and 192 ft.-lbs. (260 Nm) of yank from the 2.2L Ecotec.

The glory of it all is that the peak occurs, in the case of the walloping 2.2L engine, from just 1,900 rpm to 2,500 rpm. If that's not enough, there's remarkable flexibility, too: GM says 90% of the 2.2L's peak torque is on from 1,400 rpm to 3,750 rpm.

Opel fits the 2L Ecotecs in the Vectra (outstanding) and Omega (stolid but competent), while the 2.2L version is reserved for the Sintra minivan, which I did not drive. For now it's manual transmissions only, but Jorg Steyer, assistant staff engineer, project center diesel, at Opel's Technical Development Center Europe, says there may be automatic/Ecotec teamups later - and swears performance will not be blunted.

There are sweet, innovative details, particularly the elegant "valve-bridge" valvetrain design to open both inlet and exhaust valves via a single rocker arm; it reduces friction and permits use of just a single overhead cam. And if you must see just one assembly plant in your lifetime, make it the Ecotec plant in Kaiserslautern. It's supremely automated, startlingly clean and upbeat; meanwhile, watching the robot drop in all the cylinder head bolts - simultaneously! - precisely in their slots can turn into all-day entertainment.

New-tech diesels aren't going away - they're just too good. Are the U.S. car companies simply waiting for our emissions regulators to come to their senses?