TAKE A WALK ON THE MILD SIDE
Roll along with the engine shut down, using zero fuel? The CLS 350 is the first car in Singapore capable of that trick, and more are coming.
Many cars (including Mercedes ones) already slip into neutral automatically when you lift off the accelerator, usually when you engage an Eco driving mode. That helps the car to glide or coast, and you can travel surprisingly far that way; on some drives we’ve covered 30 percent of the distance just gliding.
EQ Boost is what gives the CLS the ability to shut down its engine while gliding.
It’s essentially a mild hybrid system. Instead of a normal starter motor, it has a powerful starter-alternator that’s connected to the engine by a belt. Running on 48 volts, it can add 14 horsepower to the crank, or more importantly 150Nm of instant torque.
That means two things. First, the engine starts up instantly and almost seamlessly, which is what enables the coasting. Second, the extra torque helps to make the engine feel extra responsive.
In day-to-day use, the engine shutdown isn’t always undetectable. Indeed, sometimes there is a noticeable jerk, usually when the engine comes alive as you’re waiting for the lights to turn green (the engine still has to run to power the air-con compressor).
But there are different EQ Boost systems; the one in the CLS 450 is smoother, mostly because its starter-generator system is more powerful, at 22hp.
Whether you care about the Earth, the pleasant surge that EQ Boost adds to the CLS engines ought to appeal to any driver. Either way, though, you’ll have to get used to it. In a little over three years’ time, every new Mercedes will come with some kind of EQ Boost system.