Quote Originally Posted by Total_Blender
Hopefully this will be an incentive to the manufacturers to bust out some engineering. I know that the hybrids are using Atkinson cycle (aka 5 stroke) engines, and Mazda did have a Miller cycle V6 engine for a while which was 13% more efficient than a conventional Otto cycle gas engine.

And Bruce Crower has built a six stroke engine that re-captures heat loss and runs without pumping coolant so theres no parasitic drag from a water pump:
http://www.autoweek.com/apps/pbcs.dl...THISWEEKSISSUE

I think whats holding us back in part is the use of the conventional gasoline fueled/otto cycle/piston engine model. I imagine the car of the future that does get 100mpg will probably have some new kind of engine thats very different from what we have now.

All of this comes back to finances. You can make a 100mpg car, but if you cant get more than 2 normal sized adults in it then it wont sell. It wont sell if it costs 60k when you can buy a 30mpg car for 20k. It wont sell if it oesnt look good. It wont sell if safety ratings are crap.


Engineering is the next step in fuel economy. I dont think you are going to find an option to replace the vehicles we like enjoy to drive with anything that is currently in the pipeline. I also think the next big breakthrough will come based more off of a diesel design than a gas engine.