Infrastructure

Gas. That's the primary infrastructure of the American traveling public.  There are gas stations just about everywhere (except at that exit you're about to pass when you really need to stop to unload some liquid instead of loading some).  What don't we have at every corner?  LPG stations (you know for LPG-powered vehicles).  Hydrogen stations (for liquid hydrogen powered vehicles, whether it's a hydrogen burning engine or a hydrogen fuel cell to create electricity from the hydrogen to power an electric motor).  240-volt quick-charging stations (for purely electric vehicles).  Granted, these technologies may be coming (or, then again, they may not be).  And there's still expense related to these types of vehicles (e.g., the Chevy Volt is much more expensive than the Chevy Cruze Eco - and the Cruze Eco actually has a higher EPA highway mileage rating!).

So, what are we to do?  Wait?  Come on, we're American, we have no patience for that!

But wait, there's something else... something that has a decent infrastructure in place already.  Something a little more closely related to gasoline: diesel.  Typically at any given "fueling location" (that is, a place with multiple gas stations) there's at least one station which sells diesel fuel.  Now, currently, we only really have the VW diesels: the TDIs (Golf, Jetta, and Passat).  (Note: I know we have plenty of large truck diesels, but I'm talking about fuel-efficient commuter cars.)  Granted, there are some BMWs, but they're more on the luxury end of the market.  Why do I mention this?  Because I think we're missing out.

Generations of Americans have been spoiled by relatively low fuel prices.  Horsepower has been the ruling stat in American vehicles, and diesel engines just don't put out the horsepower of their gasoline counterparts.  Fuel economy might be better, but most people weren't concerned about that "MPG" stat, instead looking at the "HP" number and 0-60 times from magazines and (later) web sites.  Diesel engines?  Those were the noisy, stinky, black-smoke-belching engines found in semis, some pickup trucks, and old, slow Mercedes.

Or are they?

Consider the Mini Cooper D (not available in the US): 0-60 in 8.9 seconds, 41mpg over the course of Car & Driver's two-week test, and "the sporty and fun driving experience we’re used to in gas-fired versions" - while beating the 30 and 23 mpg averages that C&D experience in regular and S model Coopers.  (Note: the Mini diesel does not meet American emission standards, so would require some reworking to be sold here.)  Similarly, the Fiat 500 diesel gets 56 mpg on the EU combined cycle.  It's only a bit over a second slower to 60 than the gas-powered 500.

So, why don't we have some of these diesels in the US?  Probably perception: they won't be "accepted" by US buyers, so going through the trouble of certifying them for American standards would seem to be a wasted expense.  But VW's TDIs seem to sell pretty well, and with current gas prices, I think more people might be interested in the diesels than most marketing types would guess.

Besides the efficiency improvements, there are some other advantages to diesels.  One is torque: because of the difference in the operating characteristics, diesel engines are much torquier than their gasoline counterparts.  For instance, that Mini diesel puts out as much torque as the much-higher-horsepower Cooper S model, and the Fiat 1.3 diesel puts out about 50% more torque than the 1.4 gas engine.  Torque is what you "feel" when accelerating - that's why a good ol' V8 engine "feels" so good and powerful.  They (diesels) won't rev as high as a gas engine, which is why they don't produce as much horsepower, but in most driving scenarios (other than running 0-60 or a 1/4-mile on a drag strip), the torque advantage more than offsets any lack of high-end power.  Diesels also generally are longer-lasting engines - they are built stronger (they have to be to withstand the diesel operating characteristics), and generally have fewer things to go wrong (e.g., no spark plugs or ignition system).

And, of course, there's that improved fuel economy.

I really hope that small diesels make their way into the US.  Mini, Fiat, even GM has some small diesels (initially engineered in conjunction with Fiat) that they could put into the Sonic line of cars (among others).  Small, light-weight, great-handling, "fun" little cars, with torquey diesel engines that get awesome mileage (even if they're slower on a drag strip than their gasoline-powered brethren) - that's what I'd like to see, and I think they may be more popular than some automotive executives might think, especially if advertised correctly.  And, the more they sell, the more word-of-mouth advertising will get around, improving the reputation of "little diesels" even more.