I've only had it for a month but 2000 Honda Accord EX L4 VTEC and I'm getting 23 mpg city. I did some highway driving and came out with a combined mileage of 25 mpg but most of the driving was city so it's hard to say what I'm getting on the highway. I imagine upwards of 29 mpg highway.

And this is with my rusty manual driving. Last time I owned a manual was about 5 years ago. Still working on smoothing out my shifting.