Alright now for the fuel economy part. You do have an automatic so fuel you won't ever get to where I'm at unfortunetly..but you can get close!
I have a 88 laredo. 3" & 31's at's, 3.55 axle swap, and a 5 speed. Its manual locks, mirrors and windows..only options on it are the gas tank skid, tow hooks and cruise! Seems like the perfect ExPo xj for me. No electrical hassle incase something gets wet, but still has cruise cause I'm lazy lol:elkgrin:
Anyway my jeeps odometer reads 283,182 miles.its frozen for some reason though, haven't pulled it apart yet. Speedo works but no odometer lol. My point is my mileage is above 300K at this point, my jeep doesn't burn coolant or oil. The motor is the OG motor thats never been rebuilt! This thing will last forever lol.
Anyway I have a lift, 31's and high mileage all fighting to kill my fuel economy. I'm getting 19 in town easily and can get 20-21 if I really baby it. I'm talking suburan area, stop lights every mile or so. And I'm usually 23mpg on the highway, I always travel at 65-68..I have got over 25mpg a few different times though. I've done a few things to help me obviously..
I want to have my XJ running on E85 1 day..its cheaper at the pump although it offers less mileage..sold fairly locally and helps the planet which is always good:wings:
Anyway the Xj can hold another 5-7 gallons of gas with just a few short hours of work. I'm actually pulling my gas tank skid in the next week or two to clean it and repaint it. But also to pull my tank and clean it thoroughly..Jeeps 23 years old so I'm sure theres some dirt or grit or something in there. I'll be doing this mod as well, except making my copper tubing closer to the top of the tank. My goal is to get it to hold 27 gallons maxium, that way I can fill it to 25.5 everytime and not guess weather my tank is full or if I should add more gas. Doing the math, at 22mpg and 25.5 gallons I can achieve 561 miles per tank..of course thats running empty. I'd say 530-540miles per tank just to be safe.
Write up seen here:
http://jeep-xj.info/HowtoFuelTank.htm
Now for fuel ecomony I'll just list what I've done.
703 dodge neon injectors, 4 hole vs our 1 hole. These are 21lbs injectors though, I now wish I would have chose the mustang 5.0 injectors as they are 19lbs. Maybe offering better mileage? Anyway performance felt better honestly, throttle response, idle and it started quicker! I gained 1mpg with these.
I have a Renix rig, our throttle bodies are 52mm stock..gayness! So I upgraded to a bored 59mm throttle body and spacer..spacer does nothing but it was free lol. Felt like I needed less throttle to maintain pace on the highway or in town. Idk if I gained anything because the lift and tires went on at the same time..I can say that I didn't lose anything either, so I believe it helped but the 31's and lift counteracted the gains lol!
I have a 2.5" exhaust with a magnaflow muffler, you already have your 2.5" so your good there.
I run the cowl intake/cheater snorkel like you do, so your good there!
I have wrapped my header in Titanium exhaust wrap..titaium kind is more heat and fire retardant I guess. But It helped in keep the temps down in the engine bay and keeps my intake manifold cooler! The colder you can get your intake charge the better off you'll be!
I also have a intake manifold heat shield. Its truely my favorite thing I've done yet! The manifold before would get so hot you couldn't even touch it, now I have no issue laying my hand on it.
I have relocated my IAT sensor. Its located on the 4th or 5th intake runner. You unscrew it & cap/plug the hole. Next, drill a single 1/2" hole in your air box, thread the sensor in and extend the wires. This allows the sensor to read true air temps vs the baking hot temps inside the intake manifold!
This is all I've done to my 23 year old jeep and she does pretty well on fuel consumption!
I am rebuilding the 4.0 this summer just because its over 300k. Its a stock rebuild with a 0 decked block, mopar .043 headgasket vs .051 stock. And a DIY hand ported head by me. I'll also be running the 68-200-4 comp cam which is slightly better then the 96-01 dual pattern cam..not by much though. The 87-95 cam is a single pattern and sucks quite honestly! The 96-01 dual pattern has way more power down low where its needed and holds it up to redline..our cam is like a hot rod cam, gradually getting more power in the RPM's.
Anyway point is I'll have a very tight quench..it'll be .049 to be exact. This will give a more complete fuel burn thus better efficeincy. The ported head is gasket matching and cleaning up flaws to help flow slightly, and the cam is only to put power where it should be! Down low in the RPM. The OEM replacement 96-01 cam is slightly over 200 bucks, the comp 68-200-4 is 200 and it comes with lifts so I chose the comp! The motor will be more efficient and make power where it should..all in all it should be more mileage!
I am also adding a E-fan at the same time. This again should help with mileage..the E-fan should help greatly. I'm also remaking my downpipe, it'll be 2.5" mandrel bent with no dent..this should help flow greatly! Haven't done it yet cause December got here and things got busy like always. My honest goal is to gain another 3 more mpg out of the jeep..the rebuild is happening cause of its age and mileage..so in the process I'm sprucing it up..But I think a steady 3 mpg with the motor, e-fan, and downpipe is reasonable! The E-fan will give me the biggest gains in town..I think its possible!
I'm hoping for 21mpg in town, and maybe 25 steady on the highway in a lifted Xj on 31's with a roof rack. Not to bad at all.
I drive my jeep to, its not always babied but when I do baby it, it repays me. I tend to leave a little early, drive a little slower..I set the cruise at 65-68mph, jump in the slow lane and listen to some tunes! When I'm trying, I'll match the speed of the big rig in front of me, Cb's are great for communicating. And I'll safely draft the rig at a safe distance! Doing this has gotten me 24-25mpg and is great practice if you do it safetly and the driver of the rig doesn't mind. I try to do this on my longer drives..
For maitenance. I run Bosch or Mobil 1 filters, never anything else..just preference! And I run 5W40 Rotella shell oil. Its got the zinc our flat tappet cam motors need. Its also got detergents and stuff in it, so it will litterally clean your motor out! The diesel guys over on the Cummins forum helped me decide! They send out test samples of there oil and such and they love Rotella so I chose it!
My first 2 oil changes I changed at 1500 miles, then 2000 miles. The first change my oil was disgustingly black, second was better. Now I change every 4000-4500 and its honey gold everytime! The diesel guys run this stuff to 6000-8000 miles but there oil filters are way bigger as well. So I stick with 4500 miles tops. Its a synthetic oil and cost less than Mobil1 which is what I used previously so I'm a happy camper, and my motor seems to be doing great. They carry this in 10W30 as well but me being in the desert, I stick with a 40 weight.
I run bosch fuel filters, fram cotton air filters, champion copper plugs, duralast wires, duralast cap and rotor. The plugs and fuel filter are changed every 25k, the cap and rotor changed every 50k, wires every 75k. Doing it this way gives me a system! Fuel filters get dirty quick, copper plugs last about 30k usually..so its dead on top of it!
Change wires for every 3 sets of plugs, change cap and rotor for every 2 sets of plugs! Doesn't cost much and I think its a big reason why my jeep gets the mileage it does. I've had this sucker since she had 103k on it, owned her for 3 1/2 years. Shes always treated me well!
K&N filters are good, but don't belong in jeeps. The flow more, filter less. Street cars aren't an issue but jeeps that see dirt are, dirt WILL get by the filter and you will find a fine thin layer of dust on the inside of your intake tube. So I stopped running them and the issue disappeared, I now stick with the Fram cotton air filters.
I followed alot of what Dino did. I didn't wrap up my intake box or pipe although I'm sure it helps and I may end up doing it at some point. Look for the intake manifold heat shield, and possibly wrap your header and relocate the IAT sensor. The colder you get the intake charge the better the mileage you'll get! Colder air is more efficient and more efficient = better mileage!
I will be ditching my cowl snorkel shortly for the hummer style intake! This will give me a ram air affect, but I'm doing it cause I'm going dual batteries and the airbox is where the second battery is going. So maybe that'll help mileage to..But its not hard to get 20/25 and say 22 combined at all!
