Metal Underground.com

Oz: Thanks for the socially conscious post. I'm honestly only familiar with the actor of the same name, I'll check out the link and find out more.

GC: To answer your question in #9, Chevy has the Volt, which takes things a small step beyond the hybrid technology of the Porsche. Not sure what Honda has. Also, that Porsche gets 'up to' 70 mpg - meaning that you probably have to drive the sports car like an old lady to consistently achieve the mileage.

ZMA: Not sure if the story is true or not. I've heard a few things like that which defied the laws of physics. There was one guy that supposedly was to convert a Hummer to a Diesel that ran on waste cooking oil, made 500+ HP and got better than 30mpg. Schwarzenegger was supposed to get one. Never heard of it becoming a reality. That same guy was working with Neil Young to do the same for a huge 60's Lincoln Continental. Neil ended up going Electric, I believe. There are alot of promises that never pan out, because the ideas aren't fully supported by the physics.
I knew a guy that worked for Bosch fuel systems. He took an early 90's Mustang with the 5.0 and reprogrammed the fuel mapping where it would run lean at cruising speeds, but normal when you put your foot in it. He got around 33mpg and could still run 13 second 1/4mile times. The only problem with doing that from the factory is the lean burn condition is hard on pistons (i.e. warranty issues). That might be able to be overcame with improved materials and direct injection is a step in that direction.
To make a long post even longer, there are just certain conservation of energy principles that limit fuel efficiency. Engines have become really efficient, but the additional baggage (like excessive emission controls) hurts more than it helps the environment IMO. Turbo Diesels can be a great step forward in the US, if people can get over their stigma that it is a dirty fuel. Europe seems to do great with them. Vehicle weight needs to come down. The old Saturn plastic body panels is something GM should have worked harder on to use in more vehicles. Plastic, Fiberglass, carbon fiber and lighter weight metals could be used more without affecting interior space and actually help load carrying abilities in trucks. Aerodynamics should also be used more on the full size trucks. They're getting to the point that they look like mini semis. That huge grill does nothing but push wind. I know they need to have larger radiators for the larger Diesels in the heavy duty models, they they could provide the same cooling capacity with a thicker radiator - not larger.
All this said, American cars are going to be made based on what the American people want. Unless we as a nation change our buying habits, the car companies are going to continue to build the heavy, gas guzzling cars and trucks that we ask for. Its a tough sell, and I too have a limit on how much I'm willing to sacrifice in performance.

(This post was last edited on September 16, 2011 at 10:31 AM ET.)