[LZ_Bayonet]

Re: Hybrids
Published on September 27, 2007

"When GM first announced their efforts of producing a hybrid system for their Troop Carrier class SUV’s the Chevy Tahoe and the GMC Yukon their estimates were for a modest 25 percent gain in fuel economy. After more testing it seems their modest estimates were too modest and that the real fuel savings has leapt to 50 percent. That would mean that this road behemoth would average around 21 mpg in the city; which is right there with the Camry. …Not so behemoth like."

"The complete EPA rating for the Tahoe/Yukon Hybrid will be 21 mpg in the city and 22 mpg on the highway. Those may not be the same average leaps found from other hybrid models, but when you consider the gasoline variant of those SUV’s gets 10 mpg in the city that is a colossal improvement. By comparison again to the Toyota Camry that 21 mpg in the city is 2 mpg better than the Camry V6 achieves."

http://www.ridelust.com/can-the-new-gm-yukontahoe-hybrid-really-match-the-camry-in-fuel-efficiency/

[chuckles]

The one not mentioned here is the hydraulic hybrid. Instead of charging batteries, the engine(diesel/gas),pumps hydraulic pressure to an accumulator that runs hydraulic motors at the wheels or drive shaft. The vehicle coming to a stop pumps pressure back into the accumulator and when the pressure rises to a pre determined pressure( 3k-5k lbs sq in), the engine goes to idle or cuts off( usually to idle to keep air conditioner running).

I saw one back in the '70's in Galveston TX demonstrated by a couple of NASA engineers. They pulled a loaded tandem dump truck with a 4 cyl Volvo down Seawall Blvd. In general, the mpg doubles with this method. They also had a Ford Grenada in Popular Science Magazine a little later that went from 16mpg with gas to over 30 mpg with the hydraulic hybrid. My aunt worked for the Galveston Daily News and followed up about a year or two later and found that someone bought the company the Nasa guys started. Not a peep after that. "Google" hydraulic hybrid and you will see Ford has one and many freight carriers are using them like UPS or Fedex. They are good for heavy vehicles because the power from hydraulic pressure is very powerful to start a truck or bus moving. You can get up to 20-30mph( depending on the size of the accumulator), before the engine kicks up off of idle. Then the engine runs at peak power to re charge the accumulator and then cuts back to idle.

I think one of the main problems is it is old tech and there isn't much you could patent as pressurized hydraulic motors have been used for 100 years. There's no money involved so it would just be to save the planet and no profit motive. I guess Ford will work on it for 20 years and Toyota will come out with one and make a few hundred billion.