Near Enough is Not Good Enough Posted June 18 2009 11:43 AM by Angus MacKenzie I've just had a few days in the new Shelby GT500. It's a pretty impressive piece -- fast, loud, and blessed with the best steering ever in an American car. It has its faults, though. The brakes don't feel man enough, the ride is borderline harsh, and the rock-hard Goodyear Eagle F1 tires leave it scrabbling for grip. But the thing that annoys me most about the GT500 -- about the whole 2010 Mustang range, for that matter -- is the live rear axle. It's the wrong technology, done for the wrong reasons; emblematic of the cynical "near enough is good enough" attitude from Motown management that helped drive Detroit's automakers into a ditch. At the launch of the S197 Mustang in late 2004, Ford countered criticism of the live rear axle -- a setup last considered state of the art by the rest of the world's automakers back in the 1970s -- by claiming an independent rear end would have added thousands of dollars to the cost of the car. That would have been correct had the S197 Mustang shared elements of the heavy and expensive DEW98 platform, which underpinned the Lincoln LS, Ford Thunderbird, and Jaguar S-Type. But it's not quite the whole story. S197 was in fact originally planned to share a lighter, simpler, less expensive independent rear suspension with the Australian-designed BA-series Falcon sedan, which launched in 2002. In fact, the rear half of the S197 platform was to be common between the two cars, with the Falcon eventually picking up the Mustang's front structure when Ford Australia could afford to replace the Falcon's ancient 4.0-liter straight six with the 3.5-liter Duratec V-6. The programs diverged because of the Falcon's need for three passenger rear seating, and the Mustang team's insistence on a subframe-mounted rear suspension, which improved isolation but compromised the rear passenger package. With the Falcon due to hit the market two years ahead of the Mustang, the Ford Australia engineers cut to the chase and developed their own independent rear end without a subframe. The Mustang team eventually gave up on a subframe, mainly for cost reasons, and developed a similar, light and low cost independent rear end of their own. Late in the S197 program, however, product development executive Phil Martens reportedly managed to convince Bill Ford Jr. he could save Ford $100 a car if the Mustang was switched to a live rear axle. The S197 platform was hurriedly torn up and reworked to accommodate the old-tech suspension. Martens was named Ford's group vice-president, product creation, North America, in October, 2003. Mustang chief engineer Hau Thai-Tang did a great job with the hand he'd been dealt, and the detail tweaks to the chassis for the 2010 model give the Mustang remarkable poise... for a live rear axle car. And there's the rub: Good as it is, the 2010 Mustang could have been better. There are a lot of good reasons why the rest of the world's automakers stopped using the Mustang's rear suspension layout decades ago. No matter how well set up, a live rear axle will never deliver the refinement, ride quality, and all-round traction of a well set up independent rear end. Yeah, yeah, I know drag racers like live rear axles, but let's be honest, how many S197s actually spend their weekends pounding quarter miles? I'd be astonished if it's more than a tiny fraction of the total number of Mustangs sold. Now here's the punchline: My well-placed sources say that once the noise, vibration and harshness, and driveline angle issues were solved, the S197's live rear axle actually ended up costing Ford $98 per unit MORE than the low cost independent rear end originally developed for the car. Go figure.