Originally Posted by
pdlamb
Well, let me just say my Prius usually gets 50 mph on the highway. The last time I did a road trip with a bike on the hitch rack, I filled up shortly after starting the return leg, and it got 35 mph coming home. I discount 5 mpg or so for the headwind, and come up with a 20% drop in mileage.
Since then the children moved away, so I can usually lay the bike in the back.
Wow, that's a lot. I just put a hitch and hitch rack on my Civic sedan last week (after using a trunk mount). I don't do much highway driving, so I can't say how it has affected mileage, although I'm sure the 40 pounds of hitch/carrier and 30 pounds of bike hanging off the back cause a significant hit, in addition to any aerodynamic issues. I'm hoping effects will be minimal with no bike on the carrier.