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William K.
User Rank
Platinum
Re: Fuel economy, 36 volt systems?
William K.   1/18/2013 8:24:50 PM
NO RATINGS
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.

Charles Murray
User Rank
Blogger
Re: Fuel stingy technologies
Charles Murray   1/18/2013 5:23:49 PM
I wish I had an answer to your question, William K. The starter-alternator was a big idea twelve years ago, then it seemed to disappear.

Rigby5
User Rank
Gold
Re: Fuel stingy technologies
Rigby5   1/18/2013 2:21:15 PM
NO RATINGS
WilliamK: I agree.  Instead of AC, vehicles can use a small swamp cooler, due to the high air movement available.  There is no loss of energy or friction, just add water.

Rigby5
User Rank
Gold
Re: Fuel technologies
Rigby5   1/18/2013 2:19:01 PM
NO RATINGS
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.

Marvin McConoughey
User Rank
Iron
Re: FUEL STINGY TECHNOLOGIES
Marvin McConoughey   1/18/2013 1:09:18 PM
NO RATINGS
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.

Marvin McConoughey
User Rank
Iron
Re: Fuel economy, 36 volt systems?
Marvin McConoughey   1/18/2013 12:58:10 PM
NO RATINGS
Quite right.  36/42 volt systems are coming and may become the standard.  Less wiring mass, smaller electrical components, and smaller space demands will make them irresistable.

William K.
User Rank
Platinum
Fuel stingy technologies
William K.   10/29/2012 7:23:39 PM
NO RATINGS
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?

William K.
User Rank
Platinum
Fuel stingy technologies
William K.   10/29/2012 7:09:10 PM
NO RATINGS
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.

Absalom
User Rank
Gold
Re: Fuel technologies
Absalom   10/17/2012 11:03:37 AM
NO RATINGS
"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. 

SparkyWatt
User Rank
Platinum
Re: Fuel technologies
SparkyWatt   10/16/2012 8:31:35 PM
NO RATINGS
Actually, as long as the passenger cage is strong enough, a 1000 pound car would not be much worse than the monsters we have today, safety wise.

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