I've noticed that the manufacturers tend to cover the rear and/or front wheels on the hybrid models more often than the regular vehicles. Are there practical or functional reasons for the covers? Is there something different about a hybrid that means a hybrid would get the covers, but a conventional car wouldn't?
1It is probably a design trend, and it's unfortunately difficult, if not impossible, to give a concrete answer here. That said, can you give an example of a vehicle with the style you are referring to? I was actually not able to find any 2017 hybrids with covered wheels, but I only did a very cursory image search. I have seen that design on many concept cars in the past decade, perhaps there is some influence there, or a designer who felt wheels were "ugly", or just wanted to be fresh and different, or really wanted to squeeze out some aerodynamics, who knows.– Jason CDec 23, 2016 at 15:08
This is not opinion based at all – at least in terms of the underlying aerodynamic principles that lead an engineer to consider using wheel fairings. Or to the tradeoffs that might lead others to choose not to seek the aerodynamic benefit. If we close these questions based on the obvious fact that very few of us are privy to the "real" reason that a particular design decision was made on a particular vehicle we'll lose the benefit of understanding the considerations that go into the decisions.– dluDec 23, 2016 at 16:36
@dlu I suspect that aerodynamic tradeoffs are a marketing ploy and that the effects are negligible, or even zero, under normal driving conditions esp. for the target market of these cars. So unless fuel efficiency studies are available, publicly, for typical road conditions, as well as design docs citing this as the reason for the change, it is anybody's guess. For all we know a mfr knows full well that it has no effect on driving and also knows full well that a consumer will buy it because it feels faster. Or its just a trend. We cannot know without being part of that design discussion.– Jason CDec 23, 2016 at 19:14
In fact, the only thing we can really say with reasonable certainty is that new hybrids don't have wheel covers, e.g. the Wikipedia article and the cursory image search. We do not actually understand the considerations that went into these decisions. We can only give our opinions. We need some pride in the site, guesswork can be found on any forum. This question isn't bad at all. But we can't answer it well, here, and we can't give it a truly unique and high quality answer.– Jason CDec 23, 2016 at 19:25
The wheel covers, or fender skirts Wikipedia says they are commonly called, are fairings installed to reduce drag in the wheel wells and thus to increase range. According to the same Wikipedia article, the Honda Insight is the only current production car that uses them.
It is not so obvious, but I would expect to see that those cars would also have "smoother than average" underbellies as well.
The downside of using a fairings at the wheel wells is that it makes them harder to service, inspect, and change the tires. In cold and wet conditions they may also contribute to the build up of snow and ice in the wheel wells.
The same article also notes the use of fender skirts on city buses as a safety measure.
Didn't know they were "fender skirts." Thanks, and Merry Christmas. Dec 28, 2016 at 16:53