Hydrogen has been touted as a viable fuel source for decades, and seemingly every day, some new or upcoming hydrogen-powered milestone is reached or discussed. However, in nearly every case, hydrogen is being touted as a standalone fuel source. But what about using pure hydrogen mixed with gasoline to increase fuel economy and reduce emissions?

Ronn Motors, of Texas, has built a car it claims will do does just that. Called the Scorpion, the engine is a 3.5-liter, six-cylinder VTEC from Acura, equipped with two turbos and an intercooler to take it from 280 hp to 450 hp. The turbo’d six is connected to an on-demand hydrogen system that breaks down water molecules and holds them in a non-pressurized tank which doesn’t necessitate the need for a hydrogen refueling station. The hydrogen is drawn through the intake manifold and between 30 and 40 percent hydrogen is mixed with the gasoline. As less gas is used, Ronn Motors says the Scorpion can do 40 mpg.

DuPont Registry just named the Scorpion a Publisher’s Choice as “one of America’s first premium eco-exotics.” True, the Tesla might be more eco, but to our eyes the Scorpion (rendering) has got the exotic thing properly nailed. But when can you get one? According to Ronn, the car will be out this fall. And when you want to get it off the lot, the 2,100-pound Scorpion will supposedly take you to 60 in no more than 3.5 seconds. Ronn will probably even throw in a full tank of gas… and water. You’ll need to provide the take-home money: $150,000. Click the link to get the full story, and check out the gallery of hi-res images below.

Back in the 70s, the first great oil shock threatened to obliterate the fun in driving. This time around, that’s not the case. Modern electronic management systems and highly efficient engines are allowing engineers to create drivetrains that provide outstanding fuel economy and performance. Combine those two elements with a great chassis and you can have a blast behind the wheel — without draining your wallet or your conscience.

Such was the case with AutoGreen, which had the opportunity to spend a few days thrashing some European unobtanium, courtesy of Bosch Automotive Systems. The MINI Cooper D (as in diesel power) combines 177 lb.-ft. of torque with the already competent MINI chassis, and delivers driving thrills while returning a massive 47 mpg!

Remember the Lightning GT? We told you about this all-electric supercar a few months ago, and it popped up today in person at the 2008 British Motor Show in London. That officially moves it one step away from the pure vaporware it was yesterday, which is a good thing since we’re eager to see the carbon fiber-bodied Lightning actually move under its own power someday. That power will be provided by the same Altairnano NanoSafe batteries used by the Phoenix SUT, though churning out the equivalent of 700bhp through four electric motors in this case.

Those motors are also the same PML wheel motors used in the 640-hp electric MINI, so they should be able to handle the 700bhp Lightning. There’s also regenerative braking, as well as pretty much every standard conveyance of luxury you would find in a normal supercar including air conditioning, sat nav, full leather, etc. Its maker is claiming a 4.0-second charge to 60 mph for the Lightning, but we’d also like to know what type of range they’re expecting in such a positively charged coupe. Unfortunately, details like that and the Lightning GT’s price are still pretty scarce, though as before, they are accepting £15,000 deposits. At least it’s no longer vapor.

Shelby Supercars has just issued its second release this week about its miraculous new project, the Ultimate Aero EV. As we read the announcement, it was obvious that it was exactly the same release from just a few days ago and the hyperbole was in no way toned down. They are promising to deliver a working prototype by February of next year, followed by full production examples by the fourth quarter of 2009. That, in and of itself, is highly improbable, but it just gets better from there. The performance the company is promising is insanely impressive and about as likely to come to fruition as airborne swine or your fairy godmother.

SSC promises two, 500hp electric motors equipped with a triple disc clutch and a six-speed gearbox. As Tesla found out the hard way, making a gearbox last with an electric motor is tough, even with half as much power. But it gets better. SSC promises a power source with extended times between charges, perhaps as long as several years. We’re still confused, but we don’t think it’s a coincidence that the company is making this announcement in the same week it announced its hopes of securing new venture funding.

Building a car powered by an internal combustion engine to go 250 mph is less of a big deal in this day and age. You just need an engine with enough power and a slippery shape. Building the kind of electric car that SSC is promising involves invalidating the most fundamental laws of physics. So for the time being, we remain comfortable skeptical