and of course, STAY AWAY FROM Ethanol!!!

 

I read that also, I have been running it (Shell 93) for about 3 months now, so 12 tanks or so. I am going to switch to 87 and see how it does in 3 more tanks. No reason for the magic number 15, it's just what I picked. I figured if Shell is truthful in saying that 93 has the cleaners in it to "clean" an engine, and 87 has the cleaners to "maintain" a clean engine, then the 93 should be able to do what it is supposed to do in 15 tanks.

This last tank I ran BP in it and it didn't do so well. I didn't drive any different and it took my mileage down to 17.83 mpg from 19.28 mpg.

 

I've decided to add one more thing to my search for mileage a ford 8.8 swap with 4.10 gears and the 4.10 gears I already have for the Dana 30. I figure it will be better geared, stronger, more after market support, disc brakes and the chance of having a limited slip.

 

that's the best idea you've had in this whole thread. lol
except a swap kit is $130, yoke adapter $30, gotta weld it up, possibly rebuild the brakes
how much money are you going to spend trying to save money on gas?

 

The adapter is 10$ the swap kit is unneeded. I can fab my own brackets and all that. I will need u bolts too. I think that's pretty much it. I figure this will be the costly mod but worth it on and off road.
As far as how much I will spend to save gas isn't to big of a deal on most things. The cool air intake, throttle body, dual electric fans, and roof rack are things I wanted to do any ways so the mileage is an added plus. The front wind deflectors weren't on my plans at all but it wouldn't cost that much to make them any ways so it's more of a why not.
I would take the things I wanted to do for other reasons than mpg's and split the price. So say I spent 60$ on a intake 30$ for hp & 30$ for mpg's. Looking at it that way I'd say the mpg side of it would be right around 250$ worth it for how much driving I do and I do see it paying for itself in 4-6 months and then after that it's all gains. I do plan on keeping this jeep throughout college and possibly longer so I want it to be as efficient and reliable as possible for when I go to college.

 

U guys are all talking about bone stock jeeps though. His is not. Which is my point. Don't lift it and stuff if u want mpgs. That's like me buying this formula 400 firebord from my buddy that's got a built motor and expecting to get good mpg. Not gonna happen.

 

Seeing as how I was able to get 18.3mpg last Friday and thats going 65mph for the drive back I can get good gas mileage. Everything I do will improve my mileage any ways. It's not like you lift it it's impossible to improve. If I would have maintained 55mph the whole way and not had to tow a truck for a few blocks in the town I was in the same night I probably would have gotten right around 20 mpg.
If you buy a formula one car your buying it to race, if you buy a jeep on rockwells and 44's your buying it for offroad. You are looking at the extreme sides.
If you buy a jeep for a daily driver you want to be able to have fun being somewhat capable then you might want to have something that's a good all around vehicle. So mileage, capability, handling, the ride, power, and you like how it looks is something you want in your daily driver. I'm not looking to have the best mileage out there the most capable and fastest I'm looking for a middle ground between them all.

 

Ok heres my 2cents worth. I have an 88, with 342k..Od stopped working there, so its probably around 400k.
Ax15, 3.55's, 31's, 2-3" lift, trimmed fenders, 15x8's with 4" of BS so they stick out. I've got 849's, 60mm TB & spacer, intake heat sheild, wrapped header, stock intake wrapped, 2.5" mandrel bent downpipe, 2.5" cat, magnapack muffler dumped before the axle. Iat sensor is relocated to my air box. Tarus Efan swap
I'm getting 18 in town on average, 19 if I baby it. And 22-23 highway. 24 with alot of drafting.


Maitenance everything, relocate your IAT, intake manifold heat sheild & wrap the header! The Efan & mandrel bent downpipe/cat showed the biggest gains! The Efan was a solid 1mpg gain in the city! And the downpipe/cat were done together showed a strong 1 mpg gain.
The injectors got my fuel ratio back in check..it showed gains but I wouldn't say it was a full 1 mpg steady. The stock intake if fine..open up the front air whole for more air flow..stock paper filter & wrap it with a sun shade to keep your intake cool!
Intake heat sheild & header wrap keeps intake charge cool!


I cruise at 65-68mph around 2000rpm which is slightly lower than perfect. I'd want around 2100rpm honestly but its the best I will get lol. 2000rpm highway cruise gets you in the sweet spot for torque..when cruising around 2000-2300 you won't need much throttle to keep the jeep moving, thus you get better mileage. Hit the slow lane & try and cruise behind the big rigs if safe & possible.

 

This is great information to know! You've done it and it's working. Your right around where I want to be. I expect to be slightly lower city than you due to the automatic trans. But I'm looking for 16 city I don't expect much there and 20's highway most of my driving is highway any ways and I feel that is the most improvable area of the mileage.

 

You need a base. So you need a 100% tune up! My motor is vin matching original. Slightly knock on start up..myabe 20-30 seconds worth. Then all is good. Has 342k on the odometer, but I know its over or very close to 400k! Its got 152+-psi across the board on a compression test!

Also with the stock air box..you can remove the silencer..its in the upper half of the airbox and is shaped like a trumpet..just pull it out! This will make it no louder..but allow more air to flow.
Heres a ram air right up..with a wrapped box..this is exactly what I've copied.
http://jeep4.0performance.4mg.com/ramair.html

Relocating your IAT sensor
http://www.angelfire.com/my/fan/IAT_sensor.html


So get your base..do it all at once! Run that suck till its almost out of fuel..then drop your tank and clean it out or drive up and down you street till it does run out. Then replace fuel filter. So all the crap off the bottom of the tank is gone!
You will also need a cap, rotor, good plug wires & Champion copper plugs. 4 hole injectors would also be good. New CPS and modify it to advance the timing 6*..
http://www.jeepstrokers.com/forum/vi...hp?f=26&t=2780

Get a new o2 sensor, replace the intake/exhaust manifold gasket. Take this time to then install your intake manfiold heat sheild & wrap the header.

Intake heat shield..you need this.
http://www.summitracing.com/parts/THE-13575/
Write up.
http://www.angelfire.com/my/fan/manifold.html



Header wrap can be bought on summitracing as well. You need 1" wide x 50' long. Look up how to wrap a header..theres 1 million write ups online. Both will help. Get either copper or titaium so the oils & such won't soak into the wrap!
DO NOT USE STAINLESS ZIPTIES! If they come with the wrap then use them, but also get some hose clamps. Use then to secure the wrap as they are much much easier to tighen & remove if ever needed! Plus stainless zip ties are ****ing expensive!


Advancing the timing will help out..and if the 6* is too much the ECU will pull it as it sees fit. So do it and let the computer do the rest. Honestly..you need to get everything & do it all at once lol..like the intake/header gasket..can be done when you wrap & do the heat sheild. You can go do your intake right now..either a cowl intake or a stock intake setup..relocate IAT sensor takes just minutes!
Everything together makes the difference...so get it all..save it all. Take a weekend and have some fun

 

Again 65mph on the highway..if you need to get somewhere on time, then leave early!
Draft when possible! It takes learning but mileage increases will show you its working! Also you can just push your roof bars to the very back to improve areodymanics slightly..takes 2 minutes anyway lol.

Also block off the radiator..small porting! Where the E-fan is..maybe a 8-10" wide block..saw that on eco modders as well. I'm on that site with my jeep as well

I coast and cruise when possible..also lights! Watch the lights. If its red, let off and coast..you may get a green before you stop Starting from a stop kills mileage...If you must stop, then stop further back and try to just roll casually so its not a 100% stop. Alot of little things add up!

Also think out your normal routes. Is there a shorter quicker way? Maybe take more right turns, so you can turn on red vs waiting at the lights! I do this often also. That way I'm not at lights idling my gas away lol

 

All the stuff you have done gave me a few ideas to work with. I do have it tuned up quite well and only has 184,000 mostly freeway/highway miles so it runs like a champ. The silencer in the intake is gone to I took that out like a year ago. I'm going to start saving for the header though. I'd like to get a performance one and wrap that and at the same time I'd like to do motor mounts. I'm going to go to the junk yard and get some fans off an Audi. Then I'll be looking for the cool air intake. After that I'll be saving for the air intake designed after the spectre one. The air deflectors I had the idea of I will probably still do just cause there cheap. If I don't see any difference in mpg I'll take them off.

 

I'd keep the stock box honestly and do a cowl setup..cost 30 bucks..its similar to the spectra. Runs up to the cowl..and the wrap your stock box. Its cheaper & better for keeping the air cooler.

Apn has a nice header..thats what I'd do..and Are you doing Brown Dog or Iron man mounts? WHich ever do poly..its worth it. I hated my rubber ones! I run Ironmans!

 

The air box isn't to bad I like to weld and I'd make it out of the exhaust pipe like the spectre I think the most expensive part would be the filter. The headers and motor mounts will come down the line as I get enough to afford them. I'll look into the cheapest one. I'm also going to look into building my own header. I really like making my own parts.

 

My buddy made and put a hydrogen generator in his jeep and I guess he's getting a lot better mileage, along with more power