It would be a mistake to count out the internal-combustion engine as yesterday’s technology, soon to expire in a puff of exhaust gas. Electrification is coming, but meanwhile engineers have offered more innovation for the venerable gas engine in the last three years than they did in the previous 20. The result is 40 mpg on the highway, from four-cylinder power plants with the same performance as older V-6s or even V-8s.
typifies the new thinking. Its target is a chronic polluter: the two-stroke oil burner normally seen in scooters, weed whackers, lawn-mowers and old Saabs. The East German Trabant used a two-stroke engine, which could usually be seen trailing a cloud of black smoke. It was rated by Time as one of the 50 worst cars ever made
Achates, an engine developer based in San Diego, claims its opposed-piston, compression-ignition two-stroke diesel (at right) can power a 40-mpg (highway) economy car like the Ford Fiesta with a 50 percent or more improvement. Yes, 60 mpg is possible, the company says, while also meeting the tough smog/greenhouse gas emissions regulations that automakers will soon face.
According to CEO Dave Johnson, the Achates innovations
include two cylinders in one combustion chamber and eliminates both the valve train and cylinder head, “giving us tremendous efficiency advantages.” It also uses less raw material and fewer components, but a completely conventional manufacturing process, which Johnson says will dramatically lower automakers power plant costs. Diesels also have an inherent fuel economy advantage.
Johnson told me all this, but Achates doesn’t actually have a car to show the press, proving its claims. I’m impressed that the company’s fuel lab boasts “laser Doppler anemometry and laser-induced fluorescence,” but I have no idea what it means. The privately held firm hasn’t signed on any high-volume automakers, though it boasts a string of Ph.D. engineers and backing from big names such as Sequoia Capital, RockPort Capital, Madrone Capital, InterWest Partners and Triangle Peak. Its founder is Dr. James Lemke, who initially drew investment from the late John Walton, son of Walmart’s Sam.
Before I proclaim this engine the greatest thing since sliced bread, I’d like to see it much further down the road. I’d want to see independent fuel economy and emissions validation. I’d want to see noise, vibration and harshness studies. I have unpleasant memories of the Trabant (at left). Frankly, I’ve had other meetings with “breakthrough” engine companies whose tech never amounted to anything. One of the biggest hurdles for companies like Achates is to get major automakers — which have huge power plant R&D staffs, after all — to want to license their innovations. Unless Achates wants to start building cars itself, that’s its only option.
Battery companies are in the same basic situation. Unless they’re vertically integrated like China’s major carmaker/battery producer BYD, they can’t go it alone. Some battery makers, with A123 as a prime example, have grabbed the brass ring of auto partners, only to run into cash-flow problems waiting for those partners (including Fisker and GM) to ramp up into large orders.
The two-stroke concept remains intriguing to auto companies, despite some setbacks. "I probably spent $50 million of GM's money proving two-strokes don't work in automobiles," GM veteran Don Runkle told Popular Mechanics
. But Runkle changed his mind, the magazine reported, when he encountered another opposed-piston design from EcoMotors' Peter Hofbauer that sounds very similar to the approach taken by Achates. EcoMotors raised $32 million from prominent investors
including Bill Gates and Khosla Ventures. Grail, Pinnacle and Transonic are other companies working on two strokes. EcoMotors claims 100 mpg is possible in a five-passenger car.
Anyway, I applaud what Achates is doing, but wouldn’t yet predict that tomorrow’s cars will have 60-mpg opposed-piston, compression-ignition two-stroke diesels under their hoods. The fact that so many key investors are putting money into two-strokes is certainly encouraging, though. Here's a techie video that explains more: