Well congrats on getting close to 30 mpg! I've had trouble getting that with almost half the horsepower you have. Obviously driving technique has a large amount to do with gas milage, especially with the hybrids. If you'll look at my milage database (non-hybrid named flower, its at 31.4 mpg right now i think) you'll see that when i started out here i was getting 23 mpg, a year later and i averaged over 30 for the same month. Harder tires here, and a little slicker oil there, but the big change has been the way i've been driving. Reading the article
here will give you a good idea on how to achieve max milage, but heres a couple of the basics. First is to accelerate slowly, the amount of energy it takes to get the mass of your car remains the same, but with slower acceleration it requires less work (yay physics!). Another is to look ahead at trafic and try not to stop, if you see you are coming up to a stoplight..go ahead and start slowing down, if you time it right, you can keep right on going. Hope that helps some..good luck!