There are all kinds of ways to boost the fuel efficiency of a vehicle. Hybrids are becoming more and more popular. Clean diesels seemed poised to make major inroads in the market. And even though they're a ways down the road, hydrogen fuel cells sure look promising.
But the problem with these technologies is that they add considerable cost to a car. Toyota has probably got the cost of its hybrid system down to about $2,500, but that's still a lot of money to add to the cost of the powertrain. At their present level of development, clean diesels probably carry $4,000-$5,000 worth of extra emissions control equipment. And hydrogen fuel cells aren't quite ready for prime time no matter what they cost.

Engine engineers complain to me all the time about these alternative technologies. They say it's unfair to compare what they are doing with gasoline-fueled piston engines to these alternatives. And it all comes down to money. They claim they can achieve comparable performance, emissions, and fuel efficiency at a lot lower cost.

Specifically, they say "Let me add just $1,000 worth of equipment and technology to my engine and let me show you what I can do."


John McElroy is host of the TV program "Autoline Detroit" and daily web video "Autoline Daily". Every week he brings his unique insights as an auto industry insider to Autoblog readers.

They make a great point. A couple years back I was able to interview Hans List, the head of AVL, the Austrian engine design company. He told me he expected to see a 70% improvement in fuel economy from gasoline-fueled piston engines by the middle of next decade. He said very small displacement engines with aggressive turbo-charging strategies would be the key.

Then there is HCCI technology, which makes a gasoline piston engine behaves much like a diesel. It promises to offer diesel-like fuel efficiency at a fraction of the cost. We may be only three to four years away from seeing a production ready HCCI engine.

But I think there could be another breakthrough on the way. Cam-less engines have been the dream of engine designers for over half a century. Using solenoids to operate the valves could eliminate a lot of mass and parasitic losses on an engine. And solenoid technology keeps getting better all the time.

There seems to be a bias against the tried and true in favor of the technology "de jour."
Even more exciting would be getting rid of poppet valves like we use in today's engines. There was some very exciting development work that took place during the Second World War using rotating valves. They looked like cylinders rotating inside of the cylinder head, in the same place an overhead cam would be, with slots cut into the cylinder to function as the intake and exhaust valves. This got rid of the reciprocating mass in the cylinder head, allowing the engine to rev much higher. But back in the 1940s they always had problems trying to seal these rotating valves.

There is some very exciting development work going on now involving sliding valves. This could provide a very simple approach to variable valve control.

The point is, the industry seems willing to invest in sexy new technology like hybrids but is reluctant to add more cost to its existing powertrains. There seems to be a bias against the tried and true in favor of the technology "de jour."

But with virtually every automaker now losing massive amounts of money, I think low-cost solutions could get a second look. So even though some of the technologies I mentioned here could add quite a bit cost to an engine, they could prove to be far more cost-effective than the glitzy bits that are getting all the attention. And that's why I keep saying that the internal combustion piston engine could be around for a lot longer than most people imagine.


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