"ABC stands for active body control, a computerised hydraulic suspension system that controls each wheel individually and, in hundredths of a second, positions it in exactly the right place, rather than depending on springs and dampers.
"This is "active" suspension, which was the latest thing in Formula One in the 1980s. Then, Lotus was the pioneer. It looked as if it had the key to the future: a way of combining the handling precision of a racing car with the serene ride of a limousine, and to eliminate body roll when cornering.
"But active suspension didn't happen. The hydraulic rams needed engine power to operate and absorbed too much, the actuating valves were difficult and expensive to make, and then such systems were banned from Formula One. Mercedes-Benz was working on active suspension at the same time. Only now, 15 years later, has it brought it to the market.
"In the new CL, the "active" elements work in conjunction with metal springs and dampers. Using 13 electronic sensors, the computer gathers the information needed to control each wheel over longer bumps and through corners. The suspension has two modes, "comfort" and "sport". Even in the stiffer sport mode, just enough body movement has been allowed to give the driver accurate feedback.
"The combination of fast, flat cornering with a gentle ride is uncanny. Mercedes chose the Côte d'Azur as an appropriately glamorous place to launch a car that is expected to attract film and sports stars as owners. The adjacent Alpes Maritimes provided challenging roads to put ABC to the test. The CL600 romped across them with the speed and enthusiasm of a much smaller and lighter car."
"With or without ACE, the new Disco does a good job of taking the hard edge off sharp bumps. It's firm, but there's enough initial compliance to keep impacts from transmitting themselves into the passenger cabin.
"My test truck did have the ACE system, and it does seem to make a difference when the corners start coming rapidly.
"Basically, the system applies hydraulic counter-pressure on the vehicle's axles when system sensors detect the onset of body roll, thus keeping the Disco more level as it corners or changes direction.
"It's essentially another approach to active suspension, and adds a distinct measure of confidence to sport-utility driving, particularly on twisty back roads.
"However, like the Discovery itself, the ACE system isn't cheap. Baked into a so-called performance package that includes 18-inch aluminum alloy wheels, it adds $2,900 to the bottom line."
"The improvement is considerable, the car now sits very flat in the bends where before it felt like the suspension was going to unload and catapult yer into the shrubbery, steering is much improved and the ride is acceptable unless you go for the really big bumps. I'm wary of speed humps and off road car parks now, but so far so good."
February 7, 2000