Toyota (NYSE: TM) seems to have a newly energized General Motors (NYSE: GM) grabbing for its throat, as the American automaker outpaced Toyota for global sales in the first three quarters of 2007 just as Toyota gained the position of the world's largest automaker after decades losing that title to its American competitor.

Add to that a loss of the top spot in auto reliability from Consumer Reports and a large Japanese recall, and Toyota -- which was shining over the summer -- has a few bruises as of late. General Motors is not sitting still, increasing its global presence very aggressively, just when Toyota probably thought it had the Detroit behemoth pinned. Toyota, ever the trendsetter, wants to gain some cachet back by making lighter cars that increase gas mileage even more than its current lineup can. After all, better gas mileage equals more sales in this day and age.

The Japanese automaker is experimenting with carbon fiber and aluminum in more designs to shed excess weight from concept vehicles, probably in an effort to firmly plant itself atop the mountain for cars that travel more and more on less and less gas. Is it a tactic to win more sales against some resurgent competitors or an effort to be an innovator? A little of both, most likely.

Consumers want the space of an SUV without the weight (poor gas economy) or the price, which is where Toyota has shined before. It can't rest on those laurels though, as GM has caught on and will join the race for more gas-efficient cars with lighter metals instead of sacrificing space. This battle has just begun, in other words.