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Thread: Gas mileage with/without rack?

  1. #1
    Registered Member

    Join Date
    Jun 2007

    Gas mileage with/without rack?

    Anyone done comparisons of gas mileage when driving with an empty roof rack vs not having the roof rack installed? I rarely use the roof rack and wonder if gas mileage is much better if I just took them off and only used them when needed.

  2. #2

    2018.5 CX-9 AWD GT

    Join Date
    Dec 2018
    I'm wondering the same thing . I only use the rack once a year on our long trip and think it looks better with the cross bars off but they are not that easy to remove unless you are a contortionist. I did not get the special tool to get to the screw's. I can't think it would affect it that much of a difference. Maybe 1 mpg. I'll probably just leave then on.

  3. #3
    Biggie T Skinny helbigtw's Avatar
    CX-3, CX-5 & CX-9 Moderator

    08 CX-9 GT Fwd, Bose/Nav, BSM,Compass/Homelink, Pwr Lift,Tow

    Join Date
    Feb 2011
    Pittsburgh, PA
    Thread bump!!
    I'm wondering same thing. My sister has told me it made a big difference on her Sienna.
    I've got 2 Yakima fork lifts and never take them off since my CX-9 is garage kept, but would put good money on betting that a rack has an affect on mpg particularly on a long road trip.

    08' CX-9 GT FWD
    Gray Mica with Black Interior
    Nav/Bose/Sunroof/Bluetooth /Rack&Crossbars/BSM/Pwr Lift/Homelink Mirror/Tow Pkg/All Weather Rear Mats
    K&N drop-in filter/Centric E-Coated rotors & Centric Posi-Quiet Ceramics /2 Yakima ForkLift Bike Trays/ Weathertech front mats
    Tires: Nitto NT421Q
    Oil: Mobile One Full Synth & Mobile One Extended Performance filter
    Problems to date: Blower motor relays replaced once, intake manifold rear brace was missing from factory build, headlamp motors weak, windshield wiper plastic cap, rear strut leak.
    Mileage: 100k
    Location: Pittsburgh, PA
    Job: Material Damage Adjuster


  4. #4
    Registered Member

    Join Date
    Jun 2007
    Here's an article about a study that shows what roof racks, loaded or unloaded, cause in reduced gas mileage:

  5. #5
    Registered Member

    Mazda CX-9 Grand Touring 2016

    Join Date
    Sep 2016
    Washington, the state
    My experience with just the Mazda crossbars in place results in a very small mileage hit. The hit to mileage is much higher with the roof box on the car. The crossbars stay on all winter. The box goes on only for a ski trip with more than 2 passengers aboard.

    Anything at all that interferes with the air flow over the body will hurt fuel consumption. The engineers designed the body in the wind tunnel; change the air flow and you upset the maximized design.

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