By MAC MORRISON (08:30 June 18, 2004) Situated in Germany's Eifel Mountains, the 14.1-mile, 170-plus turn Nürburgring Nordschleife (North Loop) hosted 20 Formula One races between 1951 and 1976. After Niki Lauda's Ferrari crashed and caught fire there in '76, F1 deemed the circuit too dangerous, but for years now it has served as the ultimate production car development course. The 'Ring's unparalleled combination of high-speed corners, severe braking zones and vertigo-inducing elevation changes offers engineers an extreme challenge on which to hone their products. Plus, the roads around Castle Nurburg are convenient for European carmakers, especially German ones like Porsche, BMW and Mercedes-Benz. It is, however, decidedly less so for U.S. or Asian manufacturers. GM was among those that decided it was worth the trip, especially since the arrival of Bob Lutz as product development czar. Since '97, GM made three to four Nürburgring trips per year, for two to three weeks per trip, says Frank Taverna, engineering group manager for General Motors' prestige, performance and luxury cars. Cadillac's CTS and CTS-V, Chevrolet's 2005 Corvette and Saturn's Ion Redline were among the cars tested on such trips. "Now, we'll probably cut down to two trips per year, two weeks per trip," Taverna says. GM hasn't capped its commitment to performance or slashed the budget. Instead, it has brought a piece of Nordschleife home, to its Milford (Michigan) Proving Ground. At 3.6-miles in its longest configuration, GM's new $7 million Milford Road Course opened in December and combines what engineers deem Nürburgring's most useful features with those of several U.S. circuits. From the German track's banked Karussell to Virginia International Raceway's esses, the course (which the media dubbed "the Lutzitsring") allows engineers to dial in cars for less money and in less time than before. "The biggest advantage is having all these features added up at one track," Taverna says. "In the past, if we had, say, an oil starvation problem, we'd have to think about the best place to go. [Spring Mountain Motorsports Park in Pahrump, Nevada] is a good place to do that. Higher-speed stuff, you'd go to VIR, and to Germany for the body-motion stuff. You couldn't really do it all at one track." With 20 turns, 98 feet of elevation change and at least five commonly used configurations, the new course impresses from behind the wheel. The MRC is so new that Taverna isn't sure of all the layout possibilities-and minor alterations were being made as late as Memorial Day. GM allowed us several laps on its own North Loop, a low-speed, 12-turn layout that includes the 25-degree high-banked left-hander that is nearly twice as steep as the 'Ring's Karussell. It provides sensations akin to driving inside-to use the development engineer's term-a toilet bowl. It's a 16.2-foot vertical drop from the top of the banking to the bottom. Later, we drove the C6 Corvette for several evaluation laps on a different configuration and found it really stretched both car and driver to their limits. (Patience, dear reader-we're not allowed to comment on the Vette until Aug. 1.) While GM hasn't let us loose on the full course, Taverna says the most commonly used 2.9-mile version allows a C5 Corvette Z06 to reach 155 mph, after which it must brake hard for a downhill decreasing-radius turn. It's a tough test, but if "validated in Milford" does not excite you quite as much as "developed at the Nürburgring," there are still those two trips to Germany per year to give street cred to GM's cars. Thanks to the MRC, engineers expect to be better prepared when they arrive. "Those trips will become more of a check-off ride," Taverna says. "When we develop a car here, we expect it to be able to go over there and function just fine."