Science Forums 2

[CraigD]

Originally Posted by alexander

So last year i was going to buy a new car, i looked at quite a few cars, i really wanted a nice clean car, eventually ended up settling on a Mazda 3 (2.3, stick, love it), but the reason i went with a non-hybrid and not an electric car is mainly due to my peeve with them, why the hell are they so damn ugly.
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I mean, Prius, ugly, Zap cars, uber ugly, Zenn, uuugly, GEM, ugly, Reva 2, gah, pointless, why why make cars that appeal to the visual perception and make people want to buy them because they look good, they run well, they pollute a lot less?

As others have already noted, beauty and ugliness are subjective qualities – personally, I found the 2000-2003 notchback Priuses (Prii?) boring, the 2004+ hatchback’s snazzy.

A car esthetics basic I learned as a kid drawing 3-angle views of imagined cars the 1970s, and 1/6th scale Plasticine models as an art major in the 1980s (I had a penchant for convincing my teachers that more or less technical stuff should be considered art project work) is that lower wheel diameter to vehicle height = more ugly. This aesthetic spells trouble for high-efficiency vehicles with large compact to midsize class interior space like the prius, since to save unsprung and total weight, they have small-diameter wheels. Consider the 3 attached tumbnails of a 2006-ish Prius with its wheels crudely scaled up and down by a factor of 1.5 and 0.75 below. If anything, the 2009+ model, with its raked window line, makes the small rear wheel/large rear quarter panel even uglier that the 2008, with its lower rear window.

Originally Posted by alexander

So why does the term Hybrid, or Electric turn a car into an ugly beast? What, does the term electric mean that you can drop all the sleek engineering, stop worrying about aerodynamic drag coefficients, and build a really ugly box on wheels?

As Zythryn noted,

Originally Posted by Zythryn

The drag coefficient of the Prius is .26 which is much better than most cars.

The 2010 Toyota Prius reduces its to 0.25, one of the best of all commonplace autos, and significantly better than alexander’s Mazda 3’s also respectable 0.29. My source for data is the wikipedia article “Automobile drag coefficient”. Interestingly, from this partial list, the 3 (not necessarily currently in) production cars with better s than the Prius’s 0.25 are the US$49,000-55,000 Mercedes E350/E550 (0.24), the “killed” GM EV1 (0.195), and the 1935-1938 Czech Tarata T77a, (0.212) of which only the EV1 was/is a high-efficiency vehicle.

Originally Posted by alexander

You know, in the age of aeronautic design principals, where every .1 of a drag coefficient translates directly into efficiency, why is it so damn difficult to design ONE car that will be appealing, both visually externally, comfortable internally, and pocket-friendly, because you know what, people, when looking for a car are not only looking for the highest mpg, but also a car they can feel comfortable in, and all the damn hybrids fail horribly!

I’ve driven a 2005 Prius cross-country, and found it as comfortable as anything I’ve driven.

It’s not as efficient when driven long distances at high nearly constant speed (48 MPG @55 MPH for 2010 model) as when driven stop and go (52 MPG), as it’s regenerative braking and on-demand only gas engine advantages are negated, making it merely a low-drag gas powered car.

The chief major practical disadvantage I’ve heard from Prius owners is that, due to their low-rolling resistance wheels and light weight, while like most front wheel drive cars, handling is good, their ability to climb and avoid getting stuck in snow and mud is significantly worse than ordinary small cars. I’ve personally seen a couple of Priuses dig themselves into inescapable ruts in about 20 cm of fresh snow. If I owned a Prius, I’d keep a set of snow chains (non-metal ones like these) in it, or at least a coil of cotton over nylon cord, which in an emergency can be made into impromptu, short-lived “chains”, in case of muddy or snowy conditions.

Originally Posted by alexander

Which got me thinking, if a hybrid gets a 50 miles per gallon, if you decrease its drag coefficient by a couple of points by designing a sleeker body and lowering the car, change to using thinner tires with an auto adjusting camber suspension, lighten up the car as much as possible by using polymer body panels where possible, make things easily replaceable, easily serviceable, use as little as you need inside for comfort, i mean some firm foam-filled bucket seats with cloth lining (basically like my maza seats, they are not super expensive, pretty light and they are damn comfy), make it plug in, coat the roof sections with the latest paint-like photovoltaics and use latest biodegradeable battery technology, how much more world-friendly would this car become, and how much one would increase that "mpg" value, and cetainly increase it's buyability?

Lots of engineering, and a few marketing questions in this sentence!

“Sleeker body” is more a aesthetic styling term than an aerodynamic one. As noted above, the somewhat boxy Prius has a much lower than many “sleeker” looking cars.

Assuming it has a reasonably aerodynamic underside, “lower the car” – reducing the clearance distance from its underside to the ground - doesn’t reduce aerodynamic drag, but increases it. The main advantages of reducing ground clearance is improving a vehicle’s maximum cornering speed and general handling by increasing aerodynamic downforce and lowering its center of gravity. Note in the previously linked wikipedia article that vehicles with extraordinary cornering speeds, such as a typical F1 racecar, have very high s of 0.7 to 1.1, while the vehicles with the lowest s, such as the Nuna multiple year World solar challenge race winner’s 0.07 have as much ground clearance as possible.

“Thinner tires”, with correspondingly higher pressure and smaller contact patches, do improve efficiency. Cars like the Prius have specially designed tires of this kind. This efficiency comes, however, at the expense of handling, as less friction corresponds to less longitudinal and lateral traction, so a balance must be found where the vehicle has good efficiency while remaining safe to drive. I’ve long imagined and wished for a system that actively changed the vehicle from riding on a very small, low resistance contact patch to a large, high traction one upon detecting a skid, wheel spin, or other loss of control or traction situation, but have seen nothing like this on any market or in any literature (other than my own ).

“Lighter body panels” – sheet metal body panels are already some of the lightest components on a passenger vehicle, so replacing them with something lighter, such as plastic, doesn’t reduce weight significantly.

The major advantage of plastic body panels is that they don’t permanently dent, and can be colored through so they don’t show scratches. The 1984-1988 Pontiac Fiero sportscar, which had easily removable plastic body panels over a tubular frame, tried this – one of its interesting features was that owner could buy and self-install aftermarket bodies to change the car to resemble other vehicles, one even as different as a small pickup truck. Pontiac dealers sold one body variant that resembled a Ferrari 328, ‘til Ferrari sued the kit’s maker, successfully ordering them to stop.

“Firm foam-filled bucket seats” have a fairly narrow age-banded market appeal, expecially if set low to the floor. A significant fraction of the car-buying public has physical difficulty getting into and out of low and/or bucket seats, hence popular cars like the Prius have very upright seating. Another disadvantage of low-slung seats are that, because they require passengers’ legs to be extended, they increase the required length of the vehicle, especially in cars with rear seats.

Photovoltaics – As mentioned upthread, the 2010 Prius has a much-advertised solar panel roof. However, this feature is used only to directly power a ventilation fan, to keep the car interior cool. It doesn’t connect to the main power system at all, and would contribute only insignificantly to it if it did.

I suspect this will be the case for nearly all hybrids and EVs for some time, as for typical vehicles and sunlight conditions, you simply can’t get much energy from a photovoltaic panel totaling the overhead surface area of a car. True solar vehicles are exotics like the above mentioned Nuna, not practical or safe for ordinary driving conditions, and actually are allowed by competition rules to spread solar cells over more than their usual area when recharging.

“Biodegradeable battery technology” – The most popular present-day hybrid battery type, NiMH, and the likely future most popular type, Li-ion, are both readily and profitably recyclable. From the few first hand contacts I’ve had with car salvage (junkyard) folk, they all participate in deal-incentived recycling programs, pulling and shipping batteries from Priuses and Honda Civic hydrids when they get them, rather than keeping them for direct resale. So I don’t think there’s much reason to pursue large biodegradable batteries for cars, because, unlike small batteries for consumer electronics (cellphones, etc.) they’re unlikely to be improperly disposed of by consumers. (info available at many sources, eg: Recycling your Battery)