2012 Toyota Prius Plug-In Hybrid - production modelEnlarge Photo
Hybrids and plug-in electric cars probably get more press than they deserve, given how small their numbers are in the vehicle fleet.
The U.S. has roughly 250 million vehicles on the roads, of which less than 2 percent are hybrids and plug-ins of all kinds.
Nonetheless, both technologies are important because they're at the leading edge of the electrification of the automobile.
Car as appliance
If you think about it, a car is one of the last major consumer appliances that doesn't run on electricity.
Not only are most home appliances electric--though not all, certainly--so are outdoor appliances like weed-whackers, lawn mowers, and the like.
We won't all be driving plug-in cars tomorrow. Or by 2020. Or even by 2050.
But the proportion of electrically-run accessories and powertrains in the fleet will increase significantly starting ... well, about now.
Electric power steering
If you buy a smaller car from pretty much any maker these days, you may (or may not) have noticed that its power steering is no longer hydraulic.
Instead, a majority of new cars are now fitted with electric power steering (EPS) that uses an electric motor to move the steering rack or arms, which saves weight and power.
Feedback then has to be simulated through some fairly sophisticated software that looks at what the front wheels are actually doing, and weights the steering wheel in the driver's hands accordingly.
Some makers are better at it than others--we like Mazda's EPS, we generally don't like Toyota's--but hydraulic power steering is conclusively on its way out.
Next, air conditioning
Hybrids and plug-in cars also now have electric air-conditioning compressors, so that the climate control remains on even when a hybrid's engine switches off.
2010 Toyota Prius 1.8-liter gasoline engine, with no accessory drive beltsEnlarge Photo
Those compressors are still more expensive than the old compressors driven by a belt running off the engine's crankshaft pulley, and many of them require a high-voltage battery pack found only in hybrids or electrics.
But that's another accessory that will move toward electrification.
In fact, many makers are working toward the "beltless" engine--using the internal-combustion powerplant solely to provide motive power for the vehicle, with everything else that might sap power being run electrically.
Ford even built a prototype car that plugs in at night just to recharge a battery that powers the accessories--but doesn't power the car.
Tougher 2025 efficiency rules
Again, it's all in service of meeting the much tougher 2025 fuel-economy rules, while automakers do their absolute best to keep changes to user perceptions of how cars actually function to a minimum--or invisible.
So what are the technologies that will let automakers comply with the gas-mileage rules--and how will they change your next car?