Hybrids: The Not So Shocking Truth

Mention the word “hybrid” on an automotive internet site and commentators clump into two camps. It’s either “I save the planet while getting 97.467 mpg driving my Prius up Pikes Peak” or “I search and destroy hippy trust-fund Prius drivers with my jacked-up diesel F-350”. Despite this ongoing socio-political clash over mixed propulsion, hybrid sales have brought the technology into the mainstream. Which puts us in a better place to answer the obvious question: what’s the future beyond the hype?

In the automobile’s infancy, battery electric vehicles (BEV’s) outsold and, in many famous cases, outperformed cars powered by internal combustion engines. But lead-acid batteries limited the BEV’s range, dooming them to obsolescence. In 1902, Ferdinand Porsche attempted to forestall the inevitable by developing the first gas – electric hybrid. Needless to say, Herr Porsche had better luck with gas-powered tanks and sports cars.

A hundred years later, Toyota had the guts, vision and cash to develop their groundbreaking series/parallel hybrid drive (gas engine and electric motor alternately or simultaneously propelling the car) using NiMH batteries. Despite its success, Toyota’s Synergy Drive has generally been seen as a transitional technology.

GM’s highly touted Volt concept (which follows Porsche’s principles closely) supposedly represents The Next Big Thing. It’s a serial hybrid– an internal combustion engine runs a generator that charges batteries that power the electric drive motor. Conceptually, it's the most efficient arrangement.

Why the century-long wait? Lead acid batteries are simply too heavy and inefficient to git er done (e.g. GM’s EV1). Suitable alternatives are just now arising. Toyota has announced that Prius III will use lithium-ion cells. As will the Tesla and GM’s Volt. The industry is searching for (and closing in on) the new Holy Grail: a small, safe, powerful, fast-recharging, affordable battery.

Meanwhile, the industry is mad about hybrids. Even the highly diesel-dependent Germans are getting into the game. DCX and BMW have a joint venture with GM to share a sophisticated dual-mode full-hybrid drive. Mercedes and BMW (hmmm) just announced a partnership to develop a second, cheaper, mild-hybrid system. And VW and Porsche are hoping that hybridizing the Touareg and Cayenne will save their SUV’s.

And no wonder. A full hybrid system can boost real world mileage by some 35 percent; that’s as great an efficiency increase (over gas power) as a diesel. Diesel fuel’s higher cost stateside (seven to 15 percent) substantially reduces any pocket-book savings. What’s more, the cost of manufacturing clean diesels is roughly equivalent to gas – electric hybrids. Hybrid components are becoming cheaper; diesels are already highly evolved.

So why not build a diesel hybrid, doubling the efficiency gain? It’s an expensive proposition, and the efficiency differential isn’t there. The Atkinson-cycle gas engine (as used in parallel hybrids) already closes the gas vs. diesel efficiency gap considerably. Improvements in valve control, direct injection and upcoming HCCI (Homogeneous Charge Compression Ignition) technology will narrow the gap further. And diesels have lost some efficiency with the latest emission controls, while the gas engine is poised for continuing economy gains.

Even if you’re not the pious Prius type, hybrid technology is already sneaking into your ride. Electric driven power steering, air-conditioning compressors and water pumps are all the fruit of hybrid technology, and spreading fast. Car builders love them; their use yields measurable fuel savings (up to 10% combined), allows quicker engine heat-up and disconnects the engine from other peripherals, making it micro-hybrid ready [see: below].

BMW just updated their 1 Series with these goodies. They also added brake energy regenerative system (iGR) that controls the alternator to charge the battery (as needed) when the engine is in over-run or going downhill. For good measure, an automatic-start-stop program kills the engine whenever neutral is engaged. Combined with improved Bi-Vanos valve control and lean-burn direct injection, the model’s efficiency has increased by 24 percent.

Prius purists may scorn, but “micro-hybrids” like the Saturn Aura Green Line are cheap ($1700 retail premium) and effective. The model’s belt driven motor/generator system yields roughly a 15 percent efficiency gain. With higher CAFE numbers on the horizon, look for more creative bundling of various degrees and forms of hybrid and related technologies. It’s not just about trying to catch or keep up with the Prius’ standard-setting full-hybrid approach.

Looking forward, plug-in hybrids like the [theoretical] Chevy Volt are inevitable. The DOE has said the US grid can recharge up to 185 million plug-in cars at night. Lithium for batteries is recyclable. Improvements in CO and other emissions are easier to deal with at the power plant source than in each car.

So if you’re in the “Prius search and destroy” camp, be prepared to keep your current battle tank going for a long time. The hybrid virus is regenerating and mutating quickly; it’ll be hard not to catch it.