Friday, 22 November 2013

Mercedes-Benz's Tesla-powered van


2014 Mercedes-Benz B-class Electric Drive
Mercedes-Benz used one of its electric B-class research vehicles to give journalists a taste of the new car.

LOS ANGELES--In a launch as quiet as the electric motor that power its wheels, Mercedes-Benz has been readying its B-class Electric Drive for sales in the summer of 2014. During the 2013 Los Angeles auto show, I joined a small group of journalists given the chance to ride along in one.
Instead of a fleet of slick vehicles prepped for the press, Mercedes-Benz only brought two examples of the B-class Electric Drive to the show. These were research vehicles that Mercedes-Benz engineers had driven for thousands of miles on public roads to collect performance data.
The B-class is one of Mercedes-Benz' European models, sort of like a compact minivan with room for five passengers and luggage. The design is practical, if a bit frumpy. It also makes a very interesting choice as Mercedes-Benz' first modern electric car.

The only other current electric car that compares to the B-class in size and utility is the Toyota RAV4 EV. Interestingly, both manufacturers leveraged partnerships with Tesla Motors to develop the electric drivetrains for the cars.
That's right, the B-class Electric Drive relies on a technology from Tesla, which should be considered a point in its favor given the success of the Model S.
However, the B-class Electric Drive, like the RAV4 EV, is a converted gasoline model. That means manufacturing advantages for Mercedes-Benz but could mean compromises in the car. With the 28 kilowatt-hour battery pack encased under the floor in the middle of the car, the rear cabin floor is just a little higher than the front, resulting in what's called 'stadium seating' for the rear seat passengers. I found no issues with headroom in back.
The other compromise is that the charging port, using the J1772 standard, is at the left rear of the car, where the fuel filler is in the gasoline version. With electric cars, a front-mounted plug is more convenient, as most people are going to park head-first, and most charging stations are positioned at the front of parking spaces.

2014 Mercedes-Benz B-class Electric Drive
A power gauge to the left of the instrument cluster shows energy usage, and a graphic on the center display shows battery level.

As for the most important number with electric cars, the lithium-ion battery pack gives the B-class Electric Drive a range, estimated by Mercedes-Benz, of 115 miles. The car has not yet been rated on a U.S. test cycle, but a Mercedes-Benz spokesperson said the company felt a range of over 100 miles was important for buyers.
Using the J1772 charging port and a 240 volt source, the car recharges in about 3.5 hours, much quicker than the Toyota RAV4 EV. Mercedes-Benz has not included any DC fast charging capability, so there will be no option for a quick, 30 minute charge-up. Similar to the Tesla Model S, a button on the dash lets the owner enable a maximum charge, which loads the battery up with an extra 15 percent, or about 18 miles. That capability is not enabled all the time as repeated use lowers the life expectancy of the battery pack.
The drive motor and power control electronics all sit under the hood, using the B-class' front-wheel-drive architecture. The 75 kilowatt motor generates 174 horsepower and 251 pound-feet of torque. Mercedes-Benz estimates it will get the B-class Electric Drive to 60 mph in 7.8 seconds.
The cabin of the car I got into was nice, with typical Mercedes-Benz styling and appointments. The leather seats were comfortable, although not power adjustable, and the circular vents showed Mercedes-Benz' most recent design cue. Sticking up in the center of the dash was an LCD. As typical in Mercedes-Benz models, the drive selector was a stalk on the steering wheel.
More intriguing were the paddle shifters on the steering wheel. Thee only thing in the car resembling a transmission would be a single reduction gear between wheels and motor. The paddles were there to engage three different braking regeneration modes, from heavy to none.
A Mercedes-Benz driver got behind the wheel and started the car with the push of a button. The dashboard and screen lit up, but there was no sound other than his explanation of the controls. With a push of the accelerator pedal we were negotiating downtown Los Angeles traffic.
My driver demonstrated repeatedly the car's full acceleration, flooring it so that the needle on the power gauge showed 100 percent power usage. While that took a toll on the battery level display graphic, it resulted in a strong, linear boost for the car. He used that acceleration to pass cars and merge onto the freeway. On a few of these full throttle starts, the motor's instant torque made the front wheels chirp.

2014 Mercedes-Benz B-class Electric Drive
The B-class Electric Drive proved just as capable on the freeway as it did on city streets.

Demonstrating the different regeneration modes, he tapped the paddle to engage full coasting, where lifting off the accelerator let the car glide, slowed only by wind resistance and friction at the wheels. At full regen, the car slowed as the drive motor reversed itself and converted our kinetic energy into electricity. But our speed didn't drop as quickly as with the Tesla Model S or BMW i3. It did not seem like one-pedal driving would work with the B-class Electric Drive.
On full regeneration, the car would not come to a complete stop, but drop down to a 4 mph creep.
I could feel little difference in the ride quality on surface streets or the freeway. The motor was, of course, quiet, but more importantly the cabin was well-insulated from noise and the suspension handled the road surfaces well. We were on a set route, though, which might have been planned to avoid any rough pavement.
The B-class Electric Drive weighs about 550 pounds more than its gasoline engine counterpart, so the suspension had to be retuned for ride and handling quality.
Although Mercedes-Benz has not detailed trim levels yet, a spokesperson at the Los Angeles auto show said it would have all the options as the standard B-class. That includes features such as navigation and a radar-based forward collision warning system. Mercedes-Benz does not have a price determined for the B-class Electric Drive yet, but a spokesperson said it would likely be in the low 40s. After government incentives, that would put the price in the low to mid-30s, not bad for any Mercedes-Benz model.
The utility of the large cabin should be attractive to American buyers, and the driving experience is certainly good for suburban transport. As with most electric cars these days, the range could still make this one impractical for many buyers. A spokesperson said the company felt over 100 miles was necessary to put range anxiety at ease, but that still might not suffice for an average round trip.
Mercedes-Benz intends to have the cars available next summer, although initial marketing will only be in select markets such as California and the Northeast.

No comments:

Post a Comment

Wednesday addams series Wednesday in short

 Follow this link to watch the Wednesday Netflix series summaru fully explained-  https://youtu.be/c13Y4XLs_AY