Re: Best Gas mileage you've gotten?
My roadster consistently returns 26-27 mpg at 70-80 mph and 28-30 mpg at 55-60. I, too, have hit over 30 a couple times after very conservative drives. Recorded in a log book for over 26,000 miles and three summers. I suspect mileage would be worse in the winter, but she spends those under a blanket in the garage. I'll be adding the K&N filters when I put her on the road in a couple weeks, but I don't expect much difference.
By comparison, the SRT6 only returned 22-23 mpg on a 360 mile round trip to Detroit at 70-75 mph last week. Same engine, but the supercharger processes the fuel even when not under hard acceleration and it's a 5-speed automatic.
The problem is that almost every trip, I accidentally run them up to 100-120 (or faster) for a brief period due to lack of self control. It's just too much fun to hit the go-fast button.