Increasing MPG with 31" All-Terrians
 

Here is my idea from my intro page, I moved it here to get more specific..
I would like to know where I can obtain the plastic sheets needed, about what thickness I would need for my application, and if it would have any noticeable affect. The bed needs to retain usage so a cap or full cover is not ideal.

Thanks you,
-James

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Specs on the truck;
2002 Ford Ranger XL, 2.3L, Automatic, 2wd, 4.10 Open Diff, 3" Front Spindle Lift, 2" Rear Blocks, 31x10.5r15 BFG All-Terrians, 15x8 American Racing Ventura Alloys, K&N 77 Series Intake System, Catback Magnaflow Dual Exhaust, SCT Tuned,,

I think that the thingie in the bed will work out if you can get the 13º angle that you're supposed to have. To measure it, take a profile shot of the truck from as far away as you can. Then measure with photoshop or a protractor.

As for underneath. More is better. The little blue triangles ain't much, as long as you're under there just cover up as much as you can. You'll have better results that way.

Also think about making some sort of wheel spoilers. I know 31" is a lot of tire to hide from the airstream, but you can at least make a dent in it.

Edit: Oh, and look up aeroheads posts, he mentions that the best bed cap is only a half cap. I don't know if he elaborated as to what half (tailgate or cab half) is best to cover, but it would still leave a lot of usable cargo space. Especially if you made it hinged somehow....

I will try to give the edges leading up to the tire a lip to deflect some of the air..

I am just afraid to mount any plastic near the engine/exhaust/transmission as the heat may distort the plastic..


A sweet goal would be 31 hwy mpg with 31's! "Green" and dirty!

Well with just better driving I went from 18.99mpg to 22.75mpg.. mixed city/hwy..

not a whole lot but a start; maybe with a few little air mods 25mpg might be possible..

might also inflate the tires from 32psi to 37..

Nice! That's nearly a 15% gain in a single tank.

Sure wish I could pull that off.

I bet when I lose the 43lbs each tires and get some 25lb ones it could be another 15% after a retune!:eek:

but first areo mods!

where do I get the plastic? hobby lobby? home depot?

Half-bedcover : General Motors holds a patent for a half-tonneau,which covers the back half of a pickup bed,and demonstrates lower drag than a full tonneau cover.If combined with a cab extender which tapers in as it projects rearward,with about a 12-degree incline at top,and 7-degree at sides,you get about 20% drag reduction and 10% fuel savings at 55-mph,12% at 70mph.Any of that exposed underbelly that can be shielded from the on-coming air will yield dividends at the pump.

as a fellow ranger owner[also on RF, same name] I can tell you that a grill block will work wonders. I have a 3in b/l 33x12.5's, and drive 3 mi's city and 75mi highway everyday. I was getting 14.5 on average, i did a grill block, and it bumped up to 15.5, and now i'm getting 18.5 by drafting whenever possible on the highway.
I'm thinking of putting my skid plate[stock steel style] one back on, and also making some side plates out of plastic. I've also been thinking of at least partial underbody panels. Like from the frame to the cab edge, it will be a sharp angle, but i'm thinking that it could help.

well your in luck, FE season is here, and I pulled 23mpg's this tank, hoping on 25 next tank and hopefully in the end 30! Good luck with the mods :thumbup:

true, i thought about that as well, but my fuel mileage has only varied 1~1.5 mpg from winter to summer. But i can tell the grill block difference, because it doesn't downshift as often or as early on my trip. Plus drafting... it won't downshift going up hill, it's great.

Ohh and FX2.3, do you have a E-fan? if not, get the one from Jusnes [?] modified. I have that and when i put it on last year it up'd me 2 mpg in town

don't worry, you'll see a noticable improvement. it will come. grillle blocks work great too.

Yeah, I bought one when they had the first group buy, but sold it to rong5, who sold it to someone else.. the 2.3L has both the mech and an electric fan.. I dont feel like touching the engine though, body panels are one thing, but the engine is not my thing..

Ill try a grille block but the only problem I see is Im in texas and it gets hot as f:eek:ck.. so it wont be a full one, I just want to smooth out the bottom and the spoiler thing..

i got 21.75 on my last tank.. and thats with +80mph on the highway and flooring it alot so Im happy with that:thumbup: but with gas now $3.35 I need to stop that..

Idea:
http://i45.photobucket.com/albums/f8...dPlate0192.jpg
Red = metal sheet
Blue = Plastic

It would be hard to cover all of the under belly as the driveshaft and muffler are the moving / hot spots.. and the rear axle needs flex room.. so I could smooth about 60% of the bottom, but that will need to wait till summer!

what metal would you use? if you were concerned about heat, aluminum would be nice. not the strongest metal though...

have you thought about boxing in the lower control arms? I've thought about it, first for offroading, now for aero. I think for aero, some plastic would work. I just need to get my hands on materials

I'm considering this on my little Bimmer, using 4' wide Coroplast for the center section, which would cover out to the bases of the control arms but sill leave sufficient gap for the wheels to steer right and left. If you need a cool air duct to ventilate the finned oil pan, a NACA inlet could very easily be made into the Coroplast, using a utility knife and foil tape.

The outboard sections of the chin fairing will be Coroplast that curves down to make wheel fairings for the front tires, more streamlined than those stubby little air dams that don't do much, anyway.

aluminum.. though aluminum is not cheap:(


Not sure exactly what you mean but this is what I did today!

http://i45.photobucket.com/albums/f8...8/IMG_5091.jpg
http://i45.photobucket.com/albums/f8...8/IMG_5088.jpg
http://i45.photobucket.com/albums/f8...8/IMG_5089.jpg
http://i45.photobucket.com/albums/f8...8/IMG_5090.jpg

Now I dont expect much if any mpg difference as is, but it will be a great test for durability.. made from 24x36 Corrugated Plastic, cut and bent..

when/if I redo them I will make them extend farther down the skid plate and add deflectors infront of the tires with an aluminum subframe for strength..

you could recycle a lot of aluminum to get some help buying some new aluminum :D

thats one way to kill a liver:eek: i mean.. errr.. no officer..

though all those cans rivited together should be enough:thumbup:

"i've got your jeep thing.. it's at the end of my tow strap."
^I kid I kid!:D

You a funny man, what with youz little 4x2... Its all good. Nothing like a little ribbing between wheelers...

"Yeah, it's a Ranger." Or "Don't worry, it's a Ranger"
Thats my answers to anyone that doesn't think i can do something in my truck, then i do it!
And I thought your Jeep thing was the reason why it burns when i pee??
HAHA

Good start man, how did you attach them? I can see something that looks like a screw in one pic. What I meant by box the control arms, is pretty much just cover or enclose the bottom open area. ZJ gave me an idea that i'm going to try out here in a few days.

Yeah, she's a mall crawler 99% of the time,, first thing my dad said when I took it offroad for the first time 4 years ago was "ITS NOT A JEEP" and I agreed!

I love wheeling just hard to find legal land to do it on.. but there is only so much a 2wd 4banger with an open diff can do eh:turtle:

Drilled into the skidplate's frame, bolted, and then screwed on the corners where you see in the pics,,

get pics when you do it!!

Well, land use issues get in the way for ya? Seriously, join up with a local offroad club. Get involved in various trail cleanups and such. Some clubs around the coutnry have access to private lands. But being a good steward of public lands is very important. EVERYTIME I go offroad I carry trashbags. And I always have some trash that I picked up. Besides, its more fun to go with a group. Easier to get unstuck or over obstacles. Out on my own, I treat 4x4 as a way OUT. 4x4 only means you will get stuck worse, farther away from help. Anyway, with a 4x2 vehicle you would be surprised where you can go. I went to some pretty cool places with my old minivan...

Pimpin a minivan eh?

I know of some jeep clubs, just never asked where/when they wheeled or if they would mind a ford playing in their mud..:cool:

What started as a joke about SUVs that NEED 4x4, and never go offroad, turned out to be a joke on me. Before long I was taking the mini in soft sand and over rough terrain and folks were wondering how I got a minivan out in the desert or on top of hills...

THere are probably more than just Jeep clubs. My local club is mostly Jeeps but we take anybody.

Looks good. Keep it coming. Im considering the same kind of setup for my Tacoma. I like how the plates double for improving mpg and protecting vital underparts when wheeling. Have you noticed any mpg improvements at all yet.

Gone wheeling at Moab at all? Probably just about the only place in Utah to wheel at.

Not been to Moab yet. Probably next fall though. Nope, lots of places to wheel in Utah still Well, until more of it becomes popular.

The plate is strong, 1/8th inch diamond plate with 1/8th inch steel frame, all bolt on.

I need to figure out a way to eliminate alot of variables before Ill know what if any results I might be getting. I do know I am now getting better hwy mpg than the epa says:eek:

I was looking at the scan guage but I thought this site was about saving $$$

talk to anybody here and they will ground it into your face until it hurts that a scan gauge saves you money. and once you get a scan gauge and find out the best way to drive, you can sell it on ebay for just about the price you bought it for.

I can't get a scan gauge, so I think I'm gonna get a vacuum gauge soon. maybe even order one right now!