Does Roof rack can cause fuel economy?

[xris]

I bought 07 CR-V last year and considering of installing a roof rack on it, perhaps a bike rack eventually. I'm wondering if that can cause dragging and perhaps affect the gas mileage (just roof rack itself). I know once I install this, it would be permanent. Anyone who have a thought on this?

[davos]

it should not have to much of influence
Figure that it will increase your drag coefficient just a bit, I don't think you will see any real difference

[xris]

Originally Posted by davos

it should not have to much of influence
Figure that it will increase your drag coefficient just a bit, I don't think you will see any real difference

Thank you Davos for your thought, I may consider buying this week.

[SJB]

I have a Thule rack on my 07'. During the winter I have a pod that I put skis in and I notice about 2.5-3 MPG loss with the box. In the Summer I run 3 Thule bike trays and notice no measurable loss of MPG.

I ran baseline MPG numbers prior to putting the rack on in both Summer and Winter conditions, so my comparisons are pretty specific.

[07exlowner]

I believe anything you put on top that creates enough resistance will cause a decrease in mileage. What that point of resistance is and how much it will decrease, I don't know.

Your best bet if you really want to know? Take the same route twice, once with the rack and the other without, in the same type of weather and try to maintain the same speed and acceleration both times. An open road for a few miles with few cars and traffic lights would work best. You'll never get conditions to be exactly the same unless you're in a wind tunnel (which is why you won't get an exact calculation) but this will probably work best for a good estimate.

Then again, you'll probably burn more gas just doing this than ever you would by having the rack on.