Detroit 2012: Mercedes-Benz Talks Engine Downsizing and Nine-Speed Transmissions

Mercedes-Benz doesn’t make do with what’s available. Take the designated conversation spaces at Cobo Hall for instance. There are plenty of nooks, crannies, and corners where one could shove a table and chairs, creating a suitable place to conduct an interview. Most automakers follow this method, but Mercedes wouldn’t even think of it. Instead they constructed a temporary office suite, complete with soft leather chairs and frosted glass doors, to host meet-and-greet’s for the two press days of NAIAS. This is where we met with Bernhard Heil, vice president of powertrain development for Mercedes-Benz.

Even more clear than his English is just how much this German cares about the work he’s doing. Simply mentioning the brand’s new SL, Heil passionately dives into an at-length description of what powers the flagship. He spends a few minutes going over the 4.6-liter, twin-turbocharged, V-8, poring over minuscule details that include centrally-located piezo fuel injectors and advanced multispark technology. He finishes his description by saying that these basic ingredients, which make up what Mercedes calls “Blue Direct” technology, will be staples in future four-cylinder engines.

Small-displacement Mercedes engines made it into the news earlier this week when Daimler announced its plan to produce four-bangers in Nissan’s Dechard, Tennessee, plant to supply engines for C-class vehicles built at Daimler’s plant in Tuscaloosa, Alabama. Maybe this will be where Benz decides to build a more potent version of the 1.8-liter found in the current SLK250, which has just about 200 horsepower. Heil acknowledges that the Benz engine is not as powerful as boosted four-cylinders being put out by competitors like BMW and Cadillac, but he tells us that the planning for that engine began in 1998 and that there is a lot of room for improvement. He also says that as engine cylinder count continues to drop, powertrain engineers may begin toying with ways to get more driving noise into the cabin, something they don’t currently dabble in with their V-6 and V-8 engines.

As Mercedes cuts displacement, it plans on adding gears to bump up efficiency even more. It’s public knowledge that Mercedes is working on and testing a nine-speed automatic transmission. When asked when we might see it, Heil declined to comment but assured us that they’re hard at work on the technology. So why nine gears? “We see a ratio with nine speeds that is absolutely efficient,” says Heil. He continues to say that if they had seen any kind of advantage adding more gears, they would have. Still, he laughs that marketing could win out in the end. When competitors come out with ten- or eleven-speed gearboxes, Mercedes-Benz may have to play along and add more gears.

The final minutes of our conversation went to a topic we’re always wondering about: small diesels bound for the US market. Right now, American buyers can have diesel technology in an E-, GL-, M-, R-, or S-class, but none of these engines are what you’d call “small.” At the 2009 New York auto show, Benz was showing off its Vision E250 BlueTEC concept powered by the company’s 2.2-liter, four-cylinder diesel, but we’ve never had a real hope of getting the engine stateside. Why? Heil says that the American buyer is still too fixated on gasoline. But when asked if we still might get to see the 2.2-liter, Heil’s response is promsing: “I think that could be the case, yes.”


Buying Guide

2012 Mercedes-Benz SLS AMG

MSRP $189,600 Base Convertible

0-60 MPH:

3.7 SECS


14 City / 20 Hwy

Horse Power:

563 @ 6800