My coworker (he's actually my boss) never really believed my outrageous gas mileage claims until now. We took a trip to San Jose, Ca from Reno, NV in my Yaris Sedan for business. He has taken the same trip on his Harley many times and averages 42 mpg on it. Together in my Yaris we got 48 mph there and 45 mpg on the way back, due to the 4000' elevation difference between Reno and San Jose. He witnessed the miles and the fillups and even brought his GPS along to verify my odometer, which were almost exactly the same.
One interesting fact is they both have 1.5L fuel injected engines.
I have a similar experience, I was able to get up to 46 in my Peug, before the autocross season started. This was much to the dismay of my motorcycle driving co-worker who thought he was doing well with his 45 mpg. It it fun to surprise people!!!
I sold my last bike because the car got better fuel mileage. The 1500 GoldWing consistently averaged 45, the VW I had then averaged 52.5 over it's lifetime.
The car was faster (though not quicker accelerating), dryer, cooler or warmer, less prone to falling over, carried me and four friends, and our gear, and I didn't have problems handing over toll money and holding the clutch lever at the same time.