|09-12-2013 09:23 AM|
|07-27-2013 03:17 PM|
As for test method, that was simple. It was a combination of things. One was of course the mpg meter built into the car's computer. Though those are not always terribly accurate. So I backed that up with a month of the diffuser on and a month of it off testing series. Then it moved to 3 months of it on and 3 months of it off. And finally 6 months on and 6 months off. Checking my mileage using fuel burned with receipts from the gas station. After almost 2 years of testing I had a pretty solid set of averages. I realize that is no lab test, but it's enough real world for most everyone I talk to. And while yes you can get +2 MPG depending on how you drive it, and there is a difference between the Wrangler and the Mustang. But aerodynamic principles still apply to both vehicles, and you ignoring that fact makes no sense at all. I made the same drive over the same road at pretty much the same times of the day almost every day of the testing. If I altered my driving at all to get more mileage, it was to drive with a lighter foot with the diffuser off. I'm sorry to disappoint you, but I drive in the real world. Unless you are saying my gas receipts and built in mpg average are lying to me, and the Jeep and Mustang are getting exactly the mpg that the factory says they are.
Where did I say lower the lifted Jeep, though now that you bring it up, I suppose you could see if the Cherokee's air suspension would fit under it. Though that would be too expensive and limit it's capabilities of going off road to some degree.And actually you are wrong. I COULD throw a plastic air damn around the car that was .25" off the ground, but that would only be useful for freeway driving and minimal street driving, as well as looking very odd. Look at the trailer on many 18 wheelers now. They do in fact have these air dams on the sides, and they do improve fuel economy AND those are way more of a brick than the Wrangler.
As for spending thousands of dollars on aero, my diffuser was $6 in aluminum and a couple hours of my time shaping it. But thank you for appraising my time's value that highly. It comes down to what you want. If you don't think you can make your money back and then some extra, then don't waste the time on it. I believe I can, and I believe it is worth it to make the attempt, especially when I can do nearly everything I plan without buying anything other than the raw materials. Aerodynamics principles apply to ALL vehicles. Check out the book Racecar Aerodynamics, and the magazine Racecar engineering. Yes they are about primarily race vehicles, but the same principles apply in all vehicles Physics doesn't change just because the shape of the vehicle changes. Or if you would rather, look into what they did at Freightliner's aerodynamic work on their trucks, which are far close to our Wranglers than they are to any racecar. And yes we do agree that weight reduction would be another route to go for mpg gains, it is just not the only route.
|07-27-2013 02:18 AM|
Welcome to Old Doggers Custom Wrangler Chop Shop..........
Just give it to me and we will start by making it into a LOW RIDER, Yes, Yes, the lower the better, get it close to the ground for good ground effects, next off comes the hood and windshield, what the heck who needs fenders, or a top, off with the both of them. Now let's put a chrome plated Blower on the engine, and that Blower will suck in the air and it will be real aerodynamic.............
See, if you really try hard enough, then there is always a realistic solution at hand...............
Now when you come to my shop, bring a lot of money, because I am very expensive...............
|07-27-2013 01:39 AM|
I want to know your test method for concluding you gained 1.2 mpg by adding a rear diffuser on a JK, although I read you it was on a mustang somewhere, so I guess that makes it pointless. Hopefully you know the body differences between a mustang and a jk and the ground clearance and all the exposed front end. Hopefully it was made in a controlled environment and not daily driving that you got these results. I can get 2+ mpg also if I wanted to by driving softly. Adding spoilers to a sports/muscle car will have much much much more gains than adding one to a jk.
You talk about the underside, I wonder if you have ever taken a look at a lifted wrangler, or stock for that matter, its quite different from a ferrari. You would have to seal the entire front and drivetrain to smooth all the parts. This is not a mustang where you can just throw plastic air dam and be at 1/2 an inch from the ground or smooth the underside and make the air flow as you want it to. This is not a car that is already low on the ground that would benefit from aerodynamic mods like a sports car, its very different adding a spoiler on a mustang than adding it to a JK, very different.
You mention armor, but, armor protects, protection comes with the cost of weight, add armor, weight goes up. There are plenty of people running armor on the underside, I wonder how many are mpg boosting. Wranglers come with a toy front plastic dam anyways, ask how many people have removed it and how many people have lost considerable mpg by taking it out. When I took it out as a suggestion from a member in another forum, I actually saw gains in mpg, but, gains were not from that, but from changes in my driving style that week I removed it, it just shows how useless air dams are on a jk, which are an eyesore btw.
Yes, as you said it, this is an enthusiast borderline fanatic topic that should be taken to its proper forum where people will appreciate it? i guess. Not many people want to spend thousands of dollars adding armor and spoilers and body mods on a jk to make it rounder to get 3-4 mpg gains. Not saying that we are haters of aerodynamics, it just does not seem worth it to start nit picking on an offroad vehicle because its not aerodynamic. Want to talk about aero improvements on a mustang, 370z, camaro, corvette? That is something worth of a discussion.
I will repost my suggestions again. Put the JK on a diet and you will see greater mpg gains than you ever will by adding spoilers. Its proven, plenty of people have posted mpg gains by shedding a lot of weight off, than they have by adding armor or a lip at the end of the hard top. They even praise the prowess of a light jk when offroading, to the point that quite a few wheel without a spare tire and many take out the seats, spare and winch on the city.
|07-26-2013 09:01 PM|
|big_slacker||I do not understand spending 1k+ to get 1-2 mpg when you could just spend the money on gas.|
|07-26-2013 08:41 PM|
I'm always amazed at posts that talk about making the Wrangler more aerodynamic, or increasing gas mileage, etc. It's almost like folks go out and by a vehicle purpose built for offroad and then complain that the gas mileage sucks.
The cross section alone should tell you that you aren't going to get great mileage or lots of speed. Sure you can put "stuff" underneath to "smooth it out", but underbody armor weighs quite a bit, in my mind defeating the purpose attempting to "smooth out the underneath."
I think my smarter than average Ensign son said it best, "Dad, I'm buying a Jeep, I'm not buying it for the mileage."
I'm happy with 17, maybe 18 miles to the gallon on a trip, I've stopped calculating mileage around town...
|07-26-2013 07:53 PM|
|07-26-2013 03:08 AM|
|07-26-2013 02:54 AM|
@gsn - You have a very good point. Once you start looking at it in parts needed, you end up rebuilding it out of a Wrangler design. Each piece alone wouldn't do a lot, and combining them all would end in a Cherokee or Liberty, or Patriot - depending on what you put together.
In the opposite direction - I have seen people get really creative and build stuff like a 4x4 Camaro. It's just is pieces again - a truck base with a Camaro body. Lots of work to do it right though, as unibody vehicles are a pita to work with and frame vehicels don't always match well either. Most of the interior ends up custom to fit the powetrain as well. A friend built a nice Powertruck, a truck 4x4 base with a 50's rat rod body on top. He can put the front bumper on a tree and idle it in low and the paddle tires will dig a hole over time. The issue here, you have to build it all.
|07-26-2013 02:31 AM|
|MRT2||Maybe not a body kit... But I do think if one had a hard top, a nice Minimal Lip spoiler would add to the asthetics. Just my 2˘.|
|07-26-2013 02:10 AM|
|2five22||Buy an old Chevy IROC and convert it to 4wd. You'll have some aerodynamics and off road capability.|
|07-26-2013 01:05 AM|
Get a cherokee then, or anything else from the jeep lineup.
Honestly, what do you want in a wrangler if you want aerodynamics? I think this question is not dumb, but something you have to make yourself and look at it objectively.
You would need to change the entire car for that to happen. First, they would not be able to bring it out with 32 inches and with the current coil length as they are coming now, it would have to be thrown down. Second, they would have to put a greater slope on the windshield. Third, they would have to change the entire design to make it less square, remove the flares, slope the grill and add a bunch of air dams and spoilery pieces. Fourth, they would have to go from a full solid front axle, to an independent front suspension, to make it more comfortable, that right there just killed the wrangler. You are basically literally describing a grand cherokee, or a cherokee, or an fj, or a land rover.
Honestly, why buy a wrangler if you want a grand cherokee? why try to f*ck up a nice offroad car, the only one left of its kind in the US.
I dont know why, for some reason, I feel my worst dream will come true in a future not too far, and chrysler will do a solid axle delete and put an IFS on the wrangler and make it a city wagon or convert into an FJ. I dont know why... just like manual wranglers are disappearing, with more non-offroaders getting the wrangler and wanting a luxury ride, they will end up pushing chrysler into killing the wrangler, and basically, a front axle will be a mod that will have to be done.
~~~~~~ Rant mode off
Bah bai, sorry if I make people cry a river.
P.S: the most mpg gaining mod that can be done is to put aluminum bumpers, dont carry any weight on the back or front like armor, winch or anything else, and dont carry a spare tire. Use 5w20 oil and drive slow. Nothing you do on the body of the wrangler aesthetically will be able to change its aerodynamics and fuel efficiency unless you start cutting and reshaping and convert it into a cherokee.
|07-25-2013 10:26 PM|
|07-25-2013 10:08 PM|
|HillbillyJeeper||Uhhhhh... Not quite sure how to deal with this post. I'll be back when drunker with a trollin smart ass post.|
|07-25-2013 10:00 PM|
The only aerodynamic Jeep I've seen, and that's mainly because it's missing the windshield!
AmphiGator Jeep WaterCar - YouTube
|07-25-2013 09:48 PM|
|07-25-2013 09:40 PM|
|Wyldeone||You could make your own aerodynamics. Sometimes small things will help in ways you did not think possible. I designed, built, and installed my own rear diffuser on a 06 mustang and gained 1.2MPG. There are lots of area on the jeep I plan to tackle a little later. The mirrors are big dumbo ears, so a set of smaller mirrors from one of the previous generations might help with that. But you are in the wrong forum for this topic. You need to check forums with people that understand the idea of aerodynamics. Not saying people in this forum are not smart enough, but enthusiasts of a particular type of vehicle (mustang owners tend to be the same way) don't usually want to bother trying things like this.|
|07-25-2013 09:32 PM|
|HappyJKU||Just take off your top and doors and bumpers and back seat and carpet, and, just make it lighter...|
|07-25-2013 09:20 PM|
OP, you're out of luck. I was interested in a nice fancy bumper COVER, like is available on most enthusiast vehicles, but when it comes to the wrangler only REAL bumpers were available. Darn.
You're in the same boat.
Either don't get a wrangler or enjoy it for its own unique image, which doesn't require body changes.
|07-25-2013 03:02 AM|
|lolpetewtf||Don't buy a Jeep. get a Juke.|
|07-25-2013 02:28 AM|
|BacaraJKU||Some may use it for good, others for bad. I sure hope there are no companies that start making ground effects for a jk. Then you're gonna see 26's dropped to the ground. Please no. Haha.|
|07-25-2013 12:59 AM|
|Lusus_Naturae||About the closest I have seen is the new air dam under the front bumper. I don't think it does much either since I never saw any difference after it was removed.|
|07-25-2013 12:50 AM|
I'm thinking of something like a quick detach air dam and something similar to the side skirts some semis have on the trailers. To limit and/or smooth the air flow under the vehicle.
I have no idea where you'd store this stuff once you got to the trailhead but I am curious about what effect if any this might have on mpg.
You're right about the ugly part - I don't see anything appealing about the jeeps pictured in this thread!
|07-25-2013 12:17 AM|
|the Kolector||Something like this?|
|07-24-2013 11:22 PM|
You could add some hydraulics to raise and lower as you want. Lowered = that's just wrong!
|07-24-2013 11:16 PM|
I just don't know how I'd add ground effects to this to make it aerodynamic.
|07-24-2013 10:24 PM|
|07-24-2013 10:20 PM|
|Lynskey||Did I stumble onto the Civic rice-burner section?|
|07-24-2013 10:20 PM|
|Lowerumble||I would try a large cone attached to the front and removable wing off the hardtop. Think Roadrunner Superbird...|
|07-24-2013 10:14 PM|
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