lowering and/or wheel skirts
 

I have Dodge Dakoat 4X4 quad cab truck. I use it infrequently for hauling large items in bed but mostly is empty with flat tanneau cover. I was reading the 65+ efficiency mods list and a few items stuck out. I will be making a aero bed cap that curves down from the cab to the tailgate and I will have some questions about that later but for now what I want to ask about it the wheel wells. There is 6.5 inches above front wheel and 10.5 inches above the rear wheel. From the list, it would seem that to lower the truck would create less area under the truck for air to go and reduce the space between the tire and the wheel well. Real world for me would be stock lower kit for 2" in front and 4" in back done by someone else so this gets me down to 4.5 front and 6.5 in back. If I add wheel skirts to smooth the air flow along the side of the truck would there be any benifit to filling the gap between the tire and the wheel well (in essence creating a smaller wheel well) along with the skirt. What I am contemplating is a foam/glass combination of wheel well reduction, skirt, wheel spat, and wheel miniboat that I could remove for winter driving or heavy hauling. And the question do I have to lower the truck at all if I am going to reduce the gap between the wheels and the wheel well or is reducing that gap worthless as far as aerodynamics for the vehicle is concerned? I am contemplating belly pan also so lowering might not be necessary for the underside.

Don

Lowering will help, but if you put on a belly pan, and wheel skirts, the need is lessened. I would try the others first then look into the lowering.

How many times do you max out the springs hauling stuff?

Never max them out.. occasional refrigerator or dryer .. dresser or such.. big but not much in the way of weight

Don

Then you can lower it and should be better off. I have not seen hard numbers on the exact % gain but we know that there is one and that it is there for the taking!

Please do some testing pre and post so we can all see what benefit it makes!
I like doing testing ABA but with something like this you can only easily do AB testing. keep in mind to get lots of data points and to keep the tests the same as possible (no wind days, long warm up both times etc).

Lowering it should help but if you are going to add a belly pan I would be that first as it will be easier to do on a raised frame. Wheel skirts will also help but I do not know if filling the wheel wells will help much or any with the skirts. After some testing with the skirts you could use some cardboard and duct tape to simulate filling it in and see if there are changes.