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'00 with CA Emissions. 161K. Pretty new cat back exhaust (Walker parts), all four O2 sensors (also newer), cleaned the IAC and throttle body awhile back, fresher plugs (Cheapo Champions), Valvoline Synthetic in both diffs, 195 degree thermostat, brand new 4 hole injectors (also newer), 225 75 15 Cooper Discovery HT's (also newer), no lift, roof rack still on, all three skids, rear factory mud flaps, factory running boards, bug deflector up front, rain guards on windows, have cruise control, newer pads and rotors, newer complete back break job, put in a leather removable headrest interior with a power driver's seat (mention this because I figure it adds a little weight), 3.55 gearing, run 35 lbs in the tires (nitrogen), and probably a couple other things that I am forgetting.
I mention all this because while I did not really care what my Jeep gets for MPG ( it is what it is) I did want it to get the best it could and wanted you guys to know the specifics.
The 2 longer trips I have taken. Little over 20 MPG on one and almost 21 MPG on the other. I am OK with that. Frankly it is a little more then I thought it would be with a CA Emissions '00.
i have the 2013 supercrew with a 5.0 it has canadian emissions and it will get 20+ mpg towing on the highway if i don't run the heck out of it
Man, that is fantastic for a gas 5.0. The best I got out of my Dodge diesel pulling a trailer and being easy on it was 18. But I'm getting 22 with a 1 ton dually when unloaded.
I certainly did not buy a Diesel thinking I would get good MPG!! LOL.....I'm lucky if I can get 18 MPG unloaded with my 2005 F350 Diesel DRW.
Lol... I was really surprised when I got it. I think the difference would be mine is the turbo Cummins 12 valve and it's only 6 cylinders. They actually do pretty good on fuel until you start building them up.
I assumed it was the diesel too. Well I'll be damned!
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I bought a welder! I just ordered it from amazon, it's an inverter DC stick welder and it was only $170! This is the one I got: http://amzn.to/2CA4wNH Since it's DC it can even weld aluminum (with aluminum welding rods) and be converted to a TIG welder with a kit.
So... get ready to see some fabrications!
First up: aerodynamically friendly roof rack. Like an Xterra's. Ok, so no roof rack is more aerodynamic than any roof rack at all but this is a Jeep god dammit and it's my adventuremobile and I may need to strap something to the roof one day.
Similar to this but without the side-to-side tubes
After that I want to build a front skid plate and possibly a rear bumper.
The problem with the rear bumper, aerodynamically speaking, is these bumper end caps sticking out and scooping air:
With those out of the way I can cut and fold the rear lower fenders and recude the amount of the sheet metal that is blocking airflow behind the rear wheels.
So if I could build something like this, that would be ideal:
I'm looking for anything that is advantageous to both off-road performance and on-road performance! Skid plates and a smaller rear bumper fit this bill perfectly.
First up: aerodynamically friendly roof rack. Like an Xterra's. Ok, so no roof rack is more aerodynamic than any roof rack at all but this is a Jeep god dammit and it's my adventuremobile and I may need to strap something to the roof one day
If you're doing it for just for possibly using it one day, why not do something removable? I use a Yakima with gutter mounts on mine to put canoes and kayaks on (lots of beautiful rivers around here), and it probably takes me 3 minutes to remove or install. I very rarely drive around with it unloaded--I just take it off when not loaded and store it ready to go in the rafters of the garage.
I'm skeptical of my assumption that removing the bodywork behind the rear wheel (cut and fold) will help reduce the drag, it might even make it worse. More research is needed, but so far my understanding is that you want "fairings" in front and behind the wheel openings to reduce the "flow detachment" (negative pressure zone that causes turbulence) that occurs behind an obstruction like a mirror, etc.
Maybe I should look into something called a diffuser. It could go under the gas tank (gas tank skid plate diffuser!!) and link to the rear bumper. Might resemble the geometry of a fastback mustang or something.
I'm trying to do some research but I'm pretty much in the dark when it comes to lifted offroad vehicles because all the wind tunnel data is made with sports cars and economy vehicles.
And the general wisdom to making these cars more aerodynamic: the lower they are to the ground the better. Well that's not going to fly with a jeep rock crawler. By lifting it, the main problem is that it's exposing more of the tires to frontal pressure by lifting the wheel well over them.
Imagine this being the tires:
Originally Posted by Tbone289
If you're doing it for just for possibly using it one day, why not do something removable? I use a Yakima with gutter mounts on mine to put canoes and kayaks on (lots of beautiful rivers around here), and it probably takes me 3 minutes to remove or install. I very rarely drive around with it unloaded--I just take it off when not loaded and store it ready to go in the rafters of the garage.
So I'm actually going to do something similar, you'll see. Some will say it's pointless, because it kinda is, but it will look cooler than stock. Basically, I'm going to build the rails that go the length of the roof, and the rails that go across the roof will be removable and will not be attached normally. I say it's kinda pointless because this is just like the stock roof rails lol but I already bought the metal and made all the cuts. Just need to weld it together and paint it.
Last edited by mannydantyla; 01-10-2018 at 11:20 AM.
I would imagine it's not tires that are your biggest factor, it's all of the exposed components hanging down. Axles, steering, springs, arms, tires...then all of the other things that contribute to hangups hanging down like they normally would (tcase, cross-members, driveshafts, mounts, sliders)
My understanding from the Ecomodding I've researched is you want to start with as flat a bottom as you can get and then start from there (when it comes to the underside of the rig)
I'm skeptical of my assumption that removing the bodywork behind the rear wheel (cut and fold) will help reduce the drag, it might even make it worse. More research is needed, but so far my understanding is that you want "fairings" in front and behind the wheel openings to reduce the "flow detachment" (negative pressure zone that causes turbulence) that occurs behind an obstruction like a mirror, etc.
Yep... Like someone else said around here, it has the aerodynamics of a brick. And like I mentioned earlier, all you can really do to help is scoop and deflect air back into the rear vacuum area to reduce the drag of this brick.
My understanding from the Ecomodding I've researched is you want to start with as flat a bottom as you can get and then start from there (when it comes to the underside of the rig)
Yup, that's what I'm doing! Hell, that might be all I can really do as I'm certainly not going to sacrifice off-road durability or anything
Originally Posted by Bugout4x4
Yep... Like someone else said around here, it has the aerodynamics of a brick. And like I mentioned earlier, all you can really do to help is scoop and deflect air back into the rear vacuum area to reduce the drag of this brick.
I got my first city MPG reading, but it's only half a tank of data:
12.7 MPG
Together with highay (16.7) make it a combined 14.4 mpg.
Not very good. Worse than I expected, tbh. Maybe I should just get a TDI motor and auto tranny... Actually, maybe I shouldn't be surprised. It's almost the EPA's city mpg of 13 for these jeeps
Originally Posted by Joshua White
The benefit of doing that is you could just kill two birds with one stone. Belly skid = flat bottom
That's my goal - find things that are helpful to both offroading and aerodynamics. You'd be surprised how many others like it I've found: fender flare delete, hood vents, rear lower fender cut and fold (I'm still figuring this one out), side mirrors delete, a gas tank skid plate that doubles as a "diffuser", etc.
Things that stick up/out/down and hit trees and branches and rocks on the trail will also hit air/wind on the highway!
Last edited by mannydantyla; 01-11-2018 at 09:44 AM.
The roof rack is off and I'm in the middle of fabricating a new one (with my new welder! turns out that welding galvanized pipe is a terrible beginner's project, lol) that will feature removable cross bars.
...
New idea: indentation of the fender right behind the front wheel, and air curtains (not to be confused with skirts!) for the front wheels! The indentation is easy; the air skirts will have to be fabricated along with a new front bumper (maybe one day far into the future). Ecomodding is an amazon thing. So many activities! So many enhancements to be made! Can you tell I'm excited!
I feel like a BIG improvement that can be made with my jeep, with the huge openings for the tires, is at the front wheels. BMW agrees, they say on their official blog that 30% of the drag is at the wheels. http://www.bmwblog.com/2014/02/26/bm...n-engineering/ (the article is really really good btw)
Also, notice the articulation of both front and rear wheels, I need every inch of the wheel well when offroading:
Lastly, here's a nice visualization of my jeep's aero:
01-05-2018, 03:53 PM
