I wondered about this too; I drove a two-door Cavalier (front drive mind you) with the new eco-tec motor and automatic. I was impressed with the power. It sounded terribly ashmatic but went like heck. 150 hp, four people on board (800 pounds of us) and 65mph up a bumpy two-lane hill. I was shocked.
Speaking of fuel economy and power, I took a long trip today that included several miles of low-range four wheeling and fueled up toward the end of my 169 miles trip. I got 27.2 mpg. How is this possible? It has 215 BFG all-terrains on 7" steel wheels but is otherwise stock. It is so slow but holds speed better than my last two Samurais so, combined with this excellent economy, I guess I'd have to say it's my best running one yet.
The first one only ran okay on premium gas and got 29mpg when stock but immediately dropped to 23mpg when I added LT215 tires (had this one since new and got rid of it around 50,000 miles). The second one, if memory serves, got about 24mpg routinely with 215s. In the nearly one year I've owned this "new" one (I'm the second owner, 42,000 miles) it's usually gotten about 26+ mpg. It feels like it's lugging a trailer behind it when getting started but once it gets going, look out !!!
I met someone who was parting out his 8v Tracker for $300 and am sort of wishing I bought it. It had a new clutch and was in running condition (he was driving it) but he said the frame where the IFS mounted was all bent and cracked up and wouldn't pass inspection without extensive work. I could kick myself for passing it up.