efficient new technologies

There is a current interest in fuel conservation among consumers today as fuel prices have finally soared in the united states. With our heritage of large automobiles and trucks, we have been lucky for some time now as we have evaded high fuel prices for a long time. Eventually this day had to come but what now? Some people say that fuel cell technologies will pave the way. This may be true but this is probably 10 or more years off in the future. Full electric cars would be alot more efficient, but batteries are still costly and heavy for now. Although this can’t be counted out as capacitor technologies may offer an alternative in the near future. Still, what until then? Hybrid technologies make sense and can use the advantages of an engine and motor combination. Hybrids are still a compromise due to the inefficient engine, what can we do to improve it? Many are quick to say the internal combustion engine is at the end of the road, but is it? More than a decade ago engines had been produced that could exceed 100 mpg. Why have these milestones been thrown aside?

 

Part of the problem that we face today is perception. What do you see more of on the road than any other vehicle, trucks and suv’s. Usually one person is driving this equivalent of a small bus around. If only we were to classify these vehicles in the same manner that cars are required to pass, things would change. The new increased price tag would minimize the amount of people wanting to drive something way larger than they need. People who need one on occasion could buy a smaller car for commuting. Manufacturers would need to produce fuel efficient trucks. Some have gone to hybrid because it’s already a heavier vehicle. If we could shift to wanting to purchase lighter reasonable sized cars, the weight would be dramatically lower. This alone would be enough to re-spark another look at current engine technologies. The new accord should receive credit as it is hybrid but is trying to advance the engine to the next level. The honda accord hybrid shuts off spark to cylinders to only run half of the engine at low load. This means as you drive down the highway with your foot lightly on the accelerator, half of the engine shuts off to conserve gas. This has been tried in the past by cadillac, but cadillac didn’t have the luxury of electronics to make it work at that time. The problem with this is that only small gains can be seen and only with your foot barely touching the pedal. Even though the engine is not using gas in some of the cylinders the other ones have to work harder. This is to move the pistons against the friction and air pumping losses. Why hasn’t someone coupled an electronic clutch between a four cylinder, essentially making two 2 cylinder engines? This would remove all parasitic and pumping losses on the shut off half of the engine. A separate electronic device could disengage the extra cylinders after acceleration. A separate throttle would have to open the remaining throttles far open, so that the driver felt no transition in the pedal. The engine would then be running at a very efficient level as the throttle would be almost wide open. This would give a similar result as a hybrid as the engine size just went in half. Diesels are also being looked at heavily for hybrid use. Diesels benefit from high compression ratios, direct injection and the fact that their throttles are always wide open. That and the fact that they operate slower makes them very efficient. Engines waste 1/3 of their power to their cooling system. Engines also waste another 1/3 of their power to the exhaust. Both of these losses are heat but some of the exhaust energy can be recovered. Turbos use the exhaust to spin and compress incoming air. This regains some of the lost energy and smaller engines can be used. A turbo is usually used for performance gain and often used with diesels. The limiting factor is that the turbo also restricts the exhaust flow. Too bad someone couldn’t find a way to heat water around the exhaust and turn it into steam or use electricity to power a turbo. The turbo would work all the time and a much smaller engine with less friction could be used. It’s hard to tell what is going to appear in the future, but I don’t think all the efficiency of an engine has yet to be found.