2014 Mercedes-Benz CLA250 Long-Term Road Test

2014 Mercedes-Benz CLA250: Stop the Auto Stop-Start

April 18, 2014

2014 Mercedes-Benz CLA250

Automatic stop-start technology in cars is a divisive issue. On the one hand, it's a not-unpleasant experience to sit at a long red light with the engine off, enjoying a bit of quiet time. On the other hand, we've strived for years to make sure we DON'T stall out in traffic and having a car do that intentionally is really, really annoying.

Especially on my commute.

I can see this technology working well for people who live in the 'burbs. Somewhere with three stop signs, two traffic lights and 20 miles of driving for every minute of stopped-time. That's not my life. My life looks like the page above. On the left hand column is my drive home including a quick errand at, oh, let's say 7pm. The column on the right, which I went ahead and noted correctly, represents the drive into work at something like 8am. Each trip was about 12 miles and took about 45 minutes. The hash marks are the stops. 41 home. 37 back.

2014 Mercedes-Benz CLA250

A stop per minute doesn't sound bad, but it's hugely annoying, especially in our CLA which has a very noticeable stop-start system. Part of this blame, I think, is due to the engine's nature: It's not quiet to begin with and has a loud starter. The next part of the blame goes to the powertrain layout. The CLA's four-cylinder is mounted transversely. Torqueing an engine that's mounted sideways seems to produce more lash and shake than doing the same with one mounted longitudinally. Something like the Mercedes-Benz GLK, for example, has a longitudinally mounted motor and has a pretty smooth start-stop. Or maybe the CLA's just got soft mounts.

Either way, I'm glad this feature has an off switch conveniently labeled "ECO". And yes, you have to turn it off again each and every time you start it up.

Mike Magrath, Features Editor @ 4,930 miles

Most Recommended Comments

By mercedesfan
on 04/18/14
12:02 PM PST

@Debunker, While I personally don't like the CLA (I personally believe someone would be much better off getting a 2-year old C250 for similar money), you have to understand that most of the complaints hinge on expectation. The quality of materials is below par for a Mercedes, the engine has a rough quality that is out of place in a Mercedes, the gas mileage is not meeting EPA estimates, etc. If compared against more reasonably priced compacts cars (such the Mazda 3, Ford Focus, etc), the CLA looks like a rock star. It's interior quality is too uneven for a luxury car, but it is leaps and bounds better than a Focus or 3. Likewise, the engine sounds a little agrarian for a luxury car, but it still sounds better and delivers vastly more power than a 3 or Focus. Similarly, the gas mileage is actually very good for a heavy and decently quick sport sedan, the EPA's numbers are just wildly optimistic. However, the CLA isn't competing against $19k economy cars. It is competing against the 320i and A3. Both of those cars make fewer compromises (particularly in regards to ride quality) and that is where the CLA starts to lose its luster.

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By Debunker
on 04/18/14
11:07 AM PST

For all the hoopla about the new little Mercedes, it has gotten slammed on a whole bunch of fronts. Cheap interior materials, harsh engine, stiff ride, tight back seat, annoying stop-start, disappointing gas mileage. Tell me again why I'd want one of these things to drive every day? Be honest. Wouldn't you be much happier in a Mazda 3, for instance, for much less money?

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