thelazydogsback Posted July 4, 2008 Share Posted July 4, 2008 Okay, reading about hypermiling and people turning off their engines downhill (not a good idea...) got me to wanting to ask this again... So, the question I have is: why are the only cars that shut off their ICE's on-demand currently hybrid cars? It seems like a no-brainer to have only cars with ICE's turn off their engines when not needed - whether at a full stop or coasting. Yes, you need a special starter/engine configuration, but you would avoid the cost, weight and environmental footprint of the battery all-together. Sure, w/o a elec. motor to take the slack, there'd be more of a stating delay, but the ICE in the 400h starts up pretty darn quickly, and if you in a performance frame of mind one could always disable the on-demand mode. Quote Link to comment Share on other sites More sharing options...
vinovelo Posted July 4, 2008 Share Posted July 4, 2008 Okay, reading about hypermiling and people turning off their engines downhill (not a good idea...) got me to wanting to ask this again...So, the question I have is: why are the only cars that shut off their ICE's on-demand currently hybrid cars? It seems like a no-brainer to have only cars with ICE's turn off their engines when not needed - whether at a full stop or coasting. Yes, you need a special starter/engine configuration, but you would avoid the cost, weight and environmental footprint of the battery all-together. Sure, w/o a elec. motor to take the slack, there'd be more of a stating delay, but the ICE in the 400h starts up pretty darn quickly, and if you in a performance frame of mind one could always disable the on-demand mode. There is more too it than that. With the Synergy system accessories like steering, braking, (as well as A/C) are electric. Coasting with the engine off in a non-hybrid car is dangerous. /Steve Quote Link to comment Share on other sites More sharing options...
thelazydogsback Posted July 4, 2008 Author Share Posted July 4, 2008 Okay, reading about hypermiling and people turning off their engines downhill (not a good idea...) got me to wanting to ask this again...So, the question I have is: why are the only cars that shut off their ICE's on-demand currently hybrid cars? It seems like a no-brainer to have only cars with ICE's turn off their engines when not needed - whether at a full stop or coasting. Yes, you need a special starter/engine configuration, but you would avoid the cost, weight and environmental footprint of the battery all-together. Sure, w/o a elec. motor to take the slack, there'd be more of a stating delay, but the ICE in the 400h starts up pretty darn quickly, and if you in a performance frame of mind one could always disable the on-demand mode. There is more too it than that. With the Synergy system accessories like steering, braking, (as well as A/C) are electric. Coasting with the engine off in a non-hybrid car is dangerous. /Steve Sure, but one would that that not having to provide energy for moving the car but just to support steering, etc., pumps that a much smaller secondary (if not beefier primary) batter could be used charged of the alternator when the ICE is running. (No elec. motors, no regen braking, smaller sec. batt.) At least under stop/go city traffic this seems like it would be woth it - but maybe you're right, could be a slippery-slope toward a full hybrid. Still, avoiding the cost of an electric drivetrain while having an engine that could shut off seems worthwhile. But you must be right, as one would think that automakers would have gone in this direction. Quote Link to comment Share on other sites More sharing options...
ljbad4life Posted July 4, 2008 Share Posted July 4, 2008 Okay, reading about hypermiling and people turning off their engines downhill (not a good idea...) got me to wanting to ask this again...So, the question I have is: why are the only cars that shut off their ICE's on-demand currently hybrid cars? It seems like a no-brainer to have only cars with ICE's turn off their engines when not needed - whether at a full stop or coasting. Yes, you need a special starter/engine configuration, but you would avoid the cost, weight and environmental footprint of the battery all-together. Sure, w/o a elec. motor to take the slack, there'd be more of a stating delay, but the ICE in the 400h starts up pretty darn quickly, and if you in a performance frame of mind one could always disable the on-demand mode. There is more too it than that. With the Synergy system accessories like steering, braking, (as well as A/C) are electric. Coasting with the engine off in a non-hybrid car is dangerous. /Steve Sure, but one would that that not having to provide energy for moving the car but just to support steering, etc., pumps that a much smaller secondary (if not beefier primary) batter could be used charged of the alternator when the ICE is running. (No elec. motors, no regen braking, smaller sec. batt.) At least under stop/go city traffic this seems like it would be woth it - but maybe you're right, could be a slippery-slope toward a full hybrid. Still, avoiding the cost of an electric drivetrain while having an engine that could shut off seems worthwhile. But you must be right, as one would think that automakers would have gone in this direction. This system you are talking about is similar to the old "hybrid" vue models that were simply start and stop and a system made by Mercedes. The start and stop system can only be effectively used when stopped for a duration (at a stop light, not while rolling) and i will explain why; It takes time for a gas engine to start ( no matter how fast a company can get it this start time will always be there), that start lag(if you call it that) means that the car will have no propulsive power at all, which could lead to accidents. Current hybrids get around the "start time" with the use of an electric motor that can atleast provide some if not all the propulsive power until the ice can start up. Add to that the fact that these start, stop system really dont save more than 1-3% of fuel (proper maintaince will save you far more!) and the extra cost to that system with such miniscule savings there quite frankly isnt a point. Mercedes Benz has been sitting on there start/stop system for over 5 years now. Quote Link to comment Share on other sites More sharing options...
s10 Posted July 5, 2008 Share Posted July 5, 2008 automatic engine start/stop is becoming more and more popular on cars in europe. Peugeot is going to make it available on all their models, most other car manufacturers are bringing out start/stop models. It is an easy thing to ad to basically any existing car. Of course it only works when the car stops, not when coasting. That would be much more complicated and really not worth it. The coasting feature on a hybrid should be seen as a nice "extra". Quote Link to comment Share on other sites More sharing options...
vinovelo Posted July 6, 2008 Share Posted July 6, 2008 Well, here is some interesting info on the subject: http://wcco.com/consumer/hybrid.conversion.kit.2.764431.html It's nice to see someone experimenting with the idea. The part about setting up conversion shops that will do this in as little as an hour tells me it's more about getting media attention for the experiment than anything else and of course the media just eats this stuff up. /Steve Quote Link to comment Share on other sites More sharing options...
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