How Do Convertible Tops Affect Fuel Economy?

There’s something about open air motoring that cannot be duplicated by a sunroof (regardless of size) or targa roof. My first car was a ragtop and I hope my last car will be as well. Needless to say, I don’t make apologies for loving convertibles.

I’ve long wondered about the effect of convertible tops on fuel economy. While I’ve never run tests on any of my own cars, I have put a number of review convertibles through highway testing loops with the top up and top down. But I haven’t had the opportunity to put a video out on the topic, until now …

The stars aligned recently, and I was able to schedule a 2013 Chrysler 200 S convertible and a 2014 Ford Mustang convertible, on back-to-back weeks. This gave me the chance to test two (of the three) American V6 convertibles available today under similar weather and traffic conditions, over an identical route.

This V6 ragtop vs V6 ragtop MPG shootout breaks new ground. I thought briefly about posting it in the MPGomatic channel, but wanted to see what the Autobytel community though of it. While the Ford Mustang and Chrysler 200 are both All-American machines, only one can be considered quintessential. I’ll bet you can guess which one I’m talking about.

I won’t spill all the beans here, but let it suffice to say that both the Mustang and 200 were more fuel efficient with their tops up. If I had more time (and money for gasoline), I would have tried testing at varying speeds, in addition to testing at our standard speed of 68 miles per hour (MPH) on the Interstate. (65 MPH is the state speed limit here in New Jersey.)

It would also be interesting to test the hard top version of the Chrysler against the soft top, not just for MPGs, but also for interior noise.

So what’s the most fuel-efficient convertible we’ve ever tested here at MPGomatic? That would be the Volkswagen Beetle TDI. Alas, it was so cold on the week that we tested the Diesel Bug that the top had to stay up …

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