Systems that send power to all four wheels certainly aren’t new, but in recent years they’ve made considerable progress in technology. Such is the case with the latest version of Mercedes-Benz’s 4MATIC all-wheel system, first seen in 2007 on the S-Class, and now available on the C-, E- and CL-Class.
“What makes this generation special, versus what else is out there, is the simplicity of the system,” says Christopher Goczan, product planning manager for Mercedes-Benz Canada. “It does away with the traditional differential locks, and uses the brains of the car to move torque around.”
The 4MATIC system works with the car’s traction and electronic stability control systems, monitoring the wheels to determine which ones are getting the most traction. The system sends 55 per cent of torque to the rear axle in normal driving conditions, but if necessary, it can deliver full power to just one wheel in order to help the driver maintain control.
“You’re talking about a system that measures in milliseconds,” Goczan says. “In that millisecond that it detects you’re getting traction again, it will let off. It would never let you lose control of the vehicle.”
Detecting within milliseconds makes the 4MATIC system faster than a mechanical system, which can have a slight lag between the time it perceives slippage and then reacts to it. It also helps make the Mercedes-Benz system smaller and lighter: it weighs only 70 kg, compared to 120 kg for the older Mercedes system it replaces. Since more weight means more fuel, all-wheel systems tend to get poorer mileage, but the lighter system creates less of a fuel consumption penalty — only about 0.7 L/100 km compared with an equivalent rear-wheel-drive system, Goczan says.
Its smaller size also means more interior space: unlike many all-wheel systems, which protrude into the floor pan with a resulting loss of foot room for the front-seat passenger, cars equipped with the new 4MATIC system look no different inside than their rear-wheel siblings.
Goczan says that with many all-wheel systems, the driver can sometimes feel the system binding. “In tight areas, you can really feel that the driveline is doing something different, and it’s not feeling natural,” he says. “Our approach is that it has to be seamless, and that’s the heart of the system. The traction and stability control are monitoring constantly so they can vary the mechanical impulses, and they control them so well that essentially, the driver never knows what’s really happening.
“You don’t know how much 4MATIC is doing in rain or snow. It’s simplicity in the driving experience.”
