Recently I'd seen a Chevy with with wheel splats (or mini air dam) in front of the rear wheels. I'd seen this long ago on the Audi TT I had and often wondered if there was any benefit to doing something like that to the ram. Well it appears Chevy felt it did contribute somehow to mpg improvement. Took a look at my trucks rear wheel openings to see if it was feasible to add one back there that dose not look obnoxious. Seems like it may be worth trying.
Another mod I'd thought of doing was adding a strip of plastic to close off the gap between the frame and the outer body panel, between the wheels. That would be out of sight, not sure if there would be any benefit or not in that area. Recently I read a writeup on the Ecodiesel that had a higher FE version of it, 2wd and it had side steps... side steps... really? They apparently felt it had an improvement.
Further reading (and getting back to) wheel well aero drag had me realize I have the rear fender liners. Not sure if that reduces drag back there or not when compared to the 1/4 liner that the truck came with. One of the thoughts I had once upon a time was to experiment with an louver on the fender liner in an effort to relieve some of the turbulence that occurs in the wheel wells.
At some point in 2018 I am going to revisit/install the 2nd air dam I had under there once upon a time. I plan to add the rear wheel front splat. That 2nd air dam was not even noticeable unless you knelt down and looked for it. AFter lowering the truck down I would expect it to have more of an affect on airflow under the truck. When I went from 3" spring to 2" spring that air dam started rattling, it was not prior to the spring swap. That told me airflow was actually hitting it. Any benefit from it I never did test for.
New Rams... I noticed a while back that that they had a seal setup somehow between the cab and the bed. I've looked at some of the truck liner seals to see if something could be had that would be cheap to pop in there but have yet to find one that would work ok.
I am thinking it will be hard to detect any change on any mod that is done as it will be a small change by itself. Collectively however it may be easier to detect. How? I'm thinking it will be easy to use the Torque app I use daily and record before and after data, looking at the calculated load on a longer loop that can be easily repeated. Where I"m at up in WA I can jump on the hiway and do an out & back easily to collect data for a 40 minute run... using CC of course and starting and stopping the log at the same points on the hiway.
Anyways, any thoughts or ideas out there worth discussing?
Disclaimer.... motivator, an evil one I will admit is to try and come close if not match the wifes new Mazda CX5's mpg of 24 mpg. Probably not gonna happen but time will tell. Remember, lighter wheels going on, going back to stock height and e-fans going in are in the near future and my truck was consistently getting low-mid 20's for mpg before the fan clutch gave me the finger. Its said that leveling kills approx 1 mpg, the fan is good for 1~1.25 mpg, lighter wheels???? unknown. If I get those 2 mpg from those 2 mods that should put me up into the 22-22.5 mpg range tank to tank (city & hiway combined).
Edit: Adding article link with useful info...
Front air dam re-installed
V2_0 of the air dam
Look @ pic, velocity of compressed airflow -> rear exit of truck.
Truck aero study
V2_0 Air Dam...
Blowing the vortex part 1
aero mods thread... this is where I document what I tried.