poor MPG after ski rack put on roof...

I'm not surprised a bit.
Still....it's a lot better than you'd get in almost anything else that you'd use to haul your sticks up to the top of a really big hill.

Careful on the way back down.

 

No real surprise - that's a lot of extra drag.

Tom

 

Maybe steep grades are a factor as well?

 

The current Prius advertises a Cd of .25 and EPA mileage of 50 MPG, the hypothetical Prius v claims a Cd of .29 and 42 MPG. Off hand increased wind resistance seems very capable of lowering MPG.

 

When translated to metric style of L/100km, or its English equivalent of gal/100mi, the extra fuel consumption you experienced is not any worse than that caused by the Thule rack formerly installed on my Honda, now put on my Subaru.

The real problem here is our this terrible 'MPG' metric that leads many people to misunderstand fuel consumption. Identical differences in fuel consumption are magnified in an N-squared fashion as base mpg rises, seriously distorting the picture that most consumers perceive.

 

Keep in mind that the coefficient of drag is proportional to the cross section that faces the wind. So a tiny sports car with a .35 Cd may have smaller absolute drag than the Prius, simply because there's less cross-sectional area. I believe the main increase of drag in the Prius v is the increased size of the vehicle, while the increased Cd (probably from things like the rear not tapering as much, among many other tiny design differences) has a smaller effect.

 

My buddy laughed when I mentioned I can't put a roof rack on my car because of wind resistance.

He has an Audi All road 2.7T chipped. Nice little all around car.

Well he couldn't believe he went from 20mpg on his long ski trips down to 17mpg. A 15% decrease. I figured if we get the same 15% it will be about 7mpg.

So that's why I want to be able to remove mine relatively easily (under 30 minutes if possible).

I'm hoping someone on here knows how long it takes to remove / reinstall these after you figure them out a few times. Any ideas???

 

Be prepared for worse than simply the same percentage mpg loss, it may be closer to the same absolute fuel penalty. Your friend's Audi is burning an extra 0.88 gallons per 100 miles when the rack is on. That would knock a 50 mpg car down to 35.