Roof racks and real world mpg

It is a given that strapping on a roof rack is probably going to affect gas mileage in some way. I happen to need a roof rack for my recently acquired '15 DCSB but won't need to use it often so I'm deliberating OEM vs Yakima crossbar style vs Prinsu style, balancing cost and ease of installation, and mpg hit. My question isn't about the merits of those racks, I'm just curious about what your experiences are with the rack you do happen to have in terms of highway and around town mpg.

In the past, I've had different experiences with different racks on different vehicles. I had a Yakima round bar setup, no fairing, on my '99 4-banger Jeep Wrangler hardtop, noticed no drop in the already kinda poor MPGs. Swapped out the hard top for a soft top a few years later, no change. Installed Thule aero-bars on my '15 Subaru crosstrek, lost about 2 mpg just commuting to work (city driving). Put a Rola roof rack on the cross bars, lost another 1-2 mpg. Put some Rola aero crossbars (mounted to the factory roof mounts) on my '12 Hyundai Accent HB, may have lost 1-2 mpg around town, hard to tell, that car was so thrifty on the gas.

What are your experiences, what rack do you have, how do you mostly use the truck?

 

I still get about 17mpg on the highway with my camper, hook off road cab rack and hook off-road rack on my camper

 

It's one of those things that will cost you fuel mileage in theory. In practice you'd have to use some pretty precise measuring methods to document it. In other words you'd have to go at least 2 digits to the right of the decimal point. The roof rack isn't going to hurt fuel mileage any more than your mirrors, door handles, radio antenna, and windshield wipers.

That is without any gear on the racks. Start loading gear up there and you will see a noticeable difference.

 

I get about 16 with my truck. Bed Rack, RTT, Winch Bumper with X20 Wireless Winch, front skid plate, Yakima Roof Rack with Awning and Bike Rack. Also have a Wilco Offset Hitchgate Offset on the back with full size spare. Lifted 3 inches with skinny 33's in 255/75/17. But in the end it's a truck and not a Prius so I really don't care about gas mileage.

 

Reviving this thread! It's been 4 years.

It has never occur to me how much roofrack can have such a big impact on mpg. I been having my victory roof rack for quite sometime now and I don't recall how much mpg I had before installing. Since then I been adding more modifications, which I kinda stop keeping track of my mpg.

With the roofrack and lightbar I was getting around 14-16 mpg, but mostly I see 15 mpg. Removing the lightbar I was seeing 18 mpg again.

I'm anticipating if I should take off the rack to see if I can gain anymore mpg just to see the difference in mpg. Just in case you guys are wondering I'm running a 3 inch lift with 285/70r17 tires, sliders, skid plate, tonneau cover as well.

I'll update on mpg with rack on and off if anyone is interested.

Hopefully this helps.

 

this is not an MPG vehicle.

just like a fork isn't used to eat soup.

 

Don't come to any conclusions after one tank of gas. That light bar isn't costing you 3 mpg. Your tires, armor, driving style, road and traffic conditions is what is hurting you.

My 07 with a cap and a roof rack on the cap will average about 17 mpg for daily driving and 20 for road trips. But that's an average. Lots of stuff happens and I've seen wildly different mpg's on individual tanks. Filled up yesterday and got 18. About 1/2 of those miles were on the interstate, about 1/2 daily driving. That's normal for my truck.

We left Utah to return to GA a few years ago. I got 22 mpg on the 1st tank, 20 on the 2nd, 16 on the 3rd, and got 20 on every other tank the rest of the way home. That's all the same day, but in very different road conditions. The tank where I got 22 was from the Colorado/Utah line to Denver. About half of it was going up, the other half coasting down. The 16mpg tank was driving in a strong headwind across Kansas. But over the nearly 5000 mile trip I averaged 20 mpg.

 

I get about 2-3 mpg better than I did before from my recordings. I know this truck doesn't give good mpg but this thread is talking about mpg so I just thought I'll give my inputs.

I basically drive on the same road, same conditions and same driving habits because it's my commute to work. I know there's a lot of variables that comes into play but this is my own recording.