Traditional air conditioning systems account for up to 5 percent of a vehicle's fuel use. Delphi Automotive says it can cut that fuel consumption with an electronically controlled compressor that can adjust its displacement to meet the varying needs of the powertrain and the passenger compartment. (Source: Delphi Automotive)
The 36 volt system is a poor choice because of the other types of problems, including poor lamp life and increased contact burning.
The way to get rid of the excess wiring mass is to get rid of the excess wiring, which would mean getting rid of all those accessories that have all those excess wires. The entire wiring harness from my 1965 vehicle could be held in one hand at arms length, including the battery cables.
The ultimate plan for getting rid of all the wires was the multiplexed control idea that had only three wires: POsitive, ground, and data. Back in the mid 90's that was supposed to be the solution. BUT it didn't work out that way, did it? Then along came the 42 volt idea, which was originally needed to power the electrically preheated catalytic converter. Fortunately for all of us that idea didn't succeed.
Presently most of those wires are already as thin as they can be mechanically and still have strength enough to survive building the car and driving it. The 36 volt-3 battery system would add more weight in the form of batterys than it would remove in the form of wires.
So the 36-42 volt system is just a bad idea, and it will continue to remain a bad idea.
Absalom: A heavy safety cage does not make a vehicle safer, but makes it more likely to lose control. And safety is from being able to maneuver and avoid collisions, not being able to withstand semi truck crushing. Smaller vehicles are inheretly stronger per weight, and therefore safer.
I believe the future CAFE standards are more sophisticated, nuanced, and less draconian than appears at first look. The innovations discussed in the article will be refined, expanded, and integrated over time to become lower cost, more effective, and more widely applied. Not discussed were such possibilities as low friction coatings, further improvements in streamlining, lower friction piston rings, and the deSaxe offset cylinder technology which is already in use for some engines. Ceramic rollers can reduce mass and friction in roller tappets. The auto industry has yet to develop low cost, low mass, engine piston pins but they are conceptually feasible and many patents exist for various approaches. Still to come are merged computerized management systems to optimize driving efficiency. These would build on fuel economy techniques already used by so-called "hypermiler" drivers who seek maximum fuel efficiency, while avoiding the extremes of slow acceleration. Turbocharging and supercharging (exhaust gas and mechanical driven alternatives) have still further developments, aided by knowledge gained from the intense ongoing aircraft engine research programs. Low friction lubricants exist now and can be further optimized and developed. Body mass is being reduced with no ultimate limit yet in sight. Fully controlled valve movement will be refined and further adopted. The future CAFE standards can be met without destroying driving pleasure.
Of the various mechanisms presented, probably the one that is able to deliver the very most improvement for the very least effort is the combination alternator-starter shown in frame 4. Engine shutoff coupled with engine disengagement, all under driver control, or possibly driver plus computer control, could easily allow a doubling of the miles per gallon during city driving. It would not offer much improvement for constant speed driving, but in the case of suburban and urban driving, the ability to shut off and coast can provide a large reduction in fuel consumption. So why hasn't anybody else proposed such a system?
Looking at the picture of the air conditioning compressor it becomes clear that very early in the process automotive air cooling must be eliminated altogether. Not only does it not contribute anything towards moving the car down the road, but it also adds to the weight of the vehicle. In addition it does a whole lot toward encouraging folks to use their cars more than they really need to use them.
"As long as the safety cage is strong enough" works for me but what can it be made of to survive being squeezed between a row of cars and an one or two 100,000 pound trucks in a typical chain reaction accident? The impact speeds may not be real high but the crushing forces are.
I wonder how safe the Datona 500 would be if they had 30 cars and 6 double trailer trucks racing around with loads scrap metal and wood chips at the same time? In real life the truckers are always racing against time and money and both their following distances and tempers can be pretty short.
I think that anything smaller than my 4x4 pickup is just a metal coffin looking for a spot to be buried. Even a 7000 pound truck is probably a bit light for safe road use. I should probably consider installing a 500 pound safety cage.
Tesla Motors’ $35,000, 200-mile electric car may not revolutionize the auto industry by itself, but it could serve as a starting point for a long, steady climb to a day when half of the world’s vehicles will be plug-ins.
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