Drive Pilot allows for the E-Class to safely follow a car in front of it at up to 130 miles per hour, and to safely stay within its lane. Even when traffic markings are obscured, it can follow the vehicle in front of it at up to 80 mph. It'll also change lanes with a two-second hold of the turn signal stalk. We'd driven the E-Class several times before the TOTY competition, and we know this system works almost seamlessly in practice. Our experience with this system on our first drive of the car, and the even more autonomous future it provides a glimpse of, is a major reason why we evaluated it in this competition.
In a more granular sense, Drive Pilot consists of several subsystems that work together to allow the E-Class to drive for long distances largely on its own. A system called Distance Pilot Distronic utilizes the radar sensors in the font bumper, which will read both the distance of the car ahead and also detect if a driver is cutting you off. If the E-Class is cut off, Distance Pilot Distronic can automatically apply the brakes at up to 50 percent of maximum power, bringing the car to a complete stop if necessary. If the system decides more intervention is needed, it'll give visual and acoustic warnings to ask the driver for sufficient braking input. If the car comes to a stop, a touch of the accelerator will resume the following feature. The various Dynamic Select drive modes affect the behavior of the system; Sport will provide more aggressive acceleration up to the set speed after an automated lane change than the Comfort setting, for example.
Steering Pilot utilizes a pair of cameras that provide a stereo view of the road ahead to determine lane markings. The system can apply torque to the wheels through the electrically assisted steering rack, for both partially autonomous driving and to assist the functions of the Active Lane Change Assist system, which also uses the radar system to check the adjacent lanes for other vehicles. Cross a line you shouldn't, and the system will provide both haptic feedback and steering intervention. Of course, you can't leave the steering wheel (or the steering wheel controls) unattended for too long before it warns you to return your hands to the wheel. Neglect the warnings and the E Class will slowly, almost gracefully come to a complete stop, as you can see demonstrated in the video above.
In practice, we've found a few limitations of the Drive Pilot system. There are some roads that are too curved for the system to handle properly, so it'll prompt for driver intervention in those cases. You can't sit back and play Sudoku; these systems are supplemental to the driver, rather than replacing him or her. Even so, it's one of the best systems we've used in practice, and that made it a must-have for our TOTY evaluations.
At this point, the Drive Pilot suite of systems is bundled exclusively with the Premium 3 package, an $11,250 option – roughly 17 percent of the total cost of a car so equipped. Whether the cost of Drive Pilot is worth the admittedly impressive functionality will be up to the buyer, but it's worth noting that it's currently not available as a stand-alone feature. With no other options selected, an E300 with the Premium 3 package retails for $65,250.