Quote Originally Posted by Thorn View Post
Well, let's see, for my case, given the bikes on the back of the car
+ Without the bikes on the back of the car, I can get 60mpg (yes, I really do)
+ With the bikes on the back of the car, I get around 45mpg
+ If the bikes are on the back of the car, we're probably driving at least 50 miles to the ride, so, use 100 miles/trip as a fair estimate
+ Over the course of the summer we'll probably do that at least once a weekend, sometimes twice, and sometimes for much longer, so use 20 times a season. That is low, but better low than high.
+ My bad math says that is a little over 10 gallons a season with the bikes on the back. People who drive my car with roof racks report 30mpg or 30 gallons a season.

Is that alot? 25-75 bucks in the US, much more elsewhere. I guess it all depends on your priorities. For me, that bothers me; for others it is no big deal. Tradeoffs.
Thorn;
so what are you driving? Just curious.

and a sidepiece to all this: so my DH just got a new, very expensive bike.
We put it on the rear rack on my car because the new bike's fenders extend so low you can't put the thing on the roof rack.
After we put the bikes (mine too) into the rack, I had to get out of the parking space. I was terrified ; I had to back up! So DH got out of the car
and directed me; driving by feel just doesn't work with an expensive bike dangling on the back!!!