First I had a 93 Oldsmobile Cutlass Ciera v6, then it started rusting horribly. Sold that car and got a used 2003 Nissan Maxima. Loved the power of the v6, but the car wasn't under warranty and horrible horrible on gas. When I bought the car, gas was around $1.90 per gallon. Now it's about 3.40.
Using new EPA guidelines
03 Maxima 3.5L V6 - 17 city, 24 hwy. Combined total = 20.
08 Altima 2.5L I-4 - 23 city, 31 hwy. Combined total = 26.
I seriously considered the hybrid, but it was several thousand more, had fewer options and I likely wouldn't qualify for the full tax credit. Not to mention Nissan is coming out with their own hybrid technology in two years. Around 20? here, still breaking in the engine (recommended for the first 1200 miles) and using the heated seats a lot. It is great to not have to use premium fuel in my tank.
I am currently averaging about 20mpg. People have posted on fueleconomy.com as high as 30mpg on the highway. Most of my driving is in suburbia... Maybe I'll spend more time here since I have a car that doesn't totally suck on gas.