# Gasoline/hydraulic hybrid **URL:** \ **Category:** General Discussion\ **Created:** [January 21, 2011, 2:49am UTC](https://community.cartalk.com/t/gasoline-hydraulic-hybrid/60242 "2011-01-21T02:49:22Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![wxf048](https://avatars.discourse-cdn.com/v4/letter/w/da6949/32.png) [@wxf048](https://community.cartalk.com/u/wxf048)\ **Post date:** [January 21, 2011, 2:49am UTC](https://community.cartalk.com/t/gasoline-hydraulic-hybrid/60242/1 "2011-01-21T02:49:22Z")
I read about a project to develop a hybrid drive system that doesn’t use batteries and electric motors. [http://mon…/index.htm](http://money.cnn.com/2011/01/19/autos/chrysler_epa_hydraulic_hybrid/index.htm) ---
**Author:** ![dagosa](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/dagosa/32/9837_2.png) [@dagosa](https://community.cartalk.com/u/dagosa)\ **Post date:** [January 21, 2011, 3:04am UTC](https://community.cartalk.com/t/gasoline-hydraulic-hybrid/60242/2 "2011-01-21T03:04:40Z")
Interesting and worth watching… The only thing I can relate it to now are skidders and hydrostatic drives on tractors which are essentially that. Though working directly off pumps and not from stored energy. The problem is with them is that though it eliminates the gear drive, it’s no where near as efficient. It works well where there is a lot of shock load as in shuttling back and forth and rapid change of directions that would be real hard on a transmission and even electric drive. There was some talk that Kubota offered to build a drive system for GM or Ford using a version of their hydro drive system; it was nixed but someone hear seemed to think it might work. Personally, I think electric traction motors seem hard to beat in efficiency. What happened to other mechanical storage devises like the flywheel ? ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [January 21, 2011, 3:22am UTC](https://community.cartalk.com/t/gasoline-hydraulic-hybrid/60242/3 "2011-01-21T03:22:30Z")
Indirectly like using compressed air. Interesting, wonder if it’s really cheaper than electric hybrid. And how do they run the a/c or heat when the engine’s off? Hydraulic pumps, I guess. ---
**Author:** ![Carveaholic](https://avatars.discourse-cdn.com/v4/letter/c/f07891/32.png) [@Carveaholic](https://community.cartalk.com/u/Carveaholic)\ **Post date:** [January 21, 2011, 3:23am UTC](https://community.cartalk.com/t/gasoline-hydraulic-hybrid/60242/4 "2011-01-21T03:23:16Z")
UPS did it; I don’t see why you couldn’t. > **[How Hydraulic Hybrids Work](https://auto.howstuffworks.com/hydraulic-hybrid3.htm)** > > The UPS hydraulic hybrid could save the company $50,000 over the lifespan of each truck. Learn how the UPS hydraulic hybrid puts the technology to good use. ---
**Author:** ![wxf048](https://avatars.discourse-cdn.com/v4/letter/w/da6949/32.png) [@wxf048](https://community.cartalk.com/u/wxf048)\ **Post date:** [January 21, 2011, 3:35am UTC](https://community.cartalk.com/t/gasoline-hydraulic-hybrid/60242/5 "2011-01-21T03:35:01Z")
I could guess about the heat. I’d guess that the engine would run constantly until it’s warmed up, since that’s when it’s most efficient. The metal and coolant and oil would retain heat even when it wasn’t running. Running occasionally would tend to keep it warmed up. If I were designing the system, I might put an electric water pump that would continue to pump coolant through the hot engine and heater core, but not the radiator, whenever the engine wasn’t running and the heater is turned on. ---
**Author:** ![euryale1](https://avatars.discourse-cdn.com/v4/letter/e/41988e/32.png) [@euryale1](https://community.cartalk.com/u/euryale1)\ **Post date:** [January 21, 2011, 4:27am UTC](https://community.cartalk.com/t/gasoline-hydraulic-hybrid/60242/6 "2011-01-21T04:27:14Z")
All you are doing is losing heat energy in the action of the pumps. The gain of maintaining a controlled rpm reaction rate for fuel combustion is lost due to the viscocity of the oil in the pumps. Electric motors are much more efficient but heavy for the torque they produce. Direct drive is the most efficient in terms of mechanical transfer heat loss(heat loss is energy lost). But for cars we have a wide range of speeds. Easy to do for equipment hard to do for cars. UPS has a different issue from most cars. Their gain comes from not idleing in city traffic, while driving all day in city traffic. Cabs could use an affordable system to reduce their idle time.