What are the best components for fuel efficiency??

I Would like to do some upgrades to my 95 country. I've seen most of the products in magazines but I wanna know from the folks who have installed. Do those tornado things really help? they seem kinda cheesy. And which air intake is most efficient? or throttle bodies? and if I get a combination of a throttle body, intake, and igntion would I see dramatic results in power/mileage? I have also seen cherokees with what looked like a draft reducing spoiler on the back- or is that just a dust sheild? Any help would be great thanks fellas. Josh

Tornado

I watch a segmant of Myth Busters about a month ago and they used the Tornado in one of the test. It was busted. Not only that but it made the test vehicle get worse fuel milage? (I have never tried it, but it looks cool) Good luck

tornados or anything that "spins" the air are all just a scam. Same with magnets. I have a K&N intake, 62mm TB and TB spacer....a high flow cat and muffler.

I've heard a lot of people say their ignition setups dont help with gas mileage...but i have a distributorless ignition, so you'll have to wait for one of them to post.

If you are out to really get better MPG, you could easily drop a grand on new intake, TB, Cat, Muffler, new plugs, low resistence wires...etc, and it would take forever for you to make up the money on gas savings.

IMHO, your best bet is a cone intake, make sure your cats arent plugged, maybe some new O2 sensors, and some good spark plugs. make sure your injectors are nice and clean, maybe seafoam your intake manifold...

Everyone else...feel free to rip apart my thoughts

The best way to improve mileage is to improve your driving habits.

That being said, anything that improves power "should" help with your fuel mileage, if you keep your foot out of it.

Lighter shoes!

At least the right one.

with the automatic... accelerate keepeing revs around 2000rpm
keep speeds at 65mph or lower
open up the stock airbox... the hole the factory provides sucks. I took a dremel tool to mine.
taurus fan swap, or another suitable electric fan swap.

This weekend I took the 90 out for a trip north, 180 miles one way. (lost my 97GC 4.0L from a rear end hit, typical MPG almost 22 on HWY). I used 3/4 of a tank on 350 miles (by the gage). I have never seen this before and I have owned it since new (now has 188K+). I attribute the improvement to the replacement fuel injectors about 2 years ago.
BTW it has a Borla exhaust, header to tail pipe. Other than adjustable map, removal of venturi in the intake between the box and TB, as well as box intake hot/cold valve removal, fully stock.
Oh yeah, all mine are auto's

Keep the fuel system clean - adding about 4oz of acetone to the tankful will help with that (and it's cheaper than injector cleaner.) The jury is still out on how much it helps with fuel mileage - but keeping the system clean certainly can't hurt.

Steady-State cruising. Don't speed up or slow down - for longish trips, set cruise control if you have it.

No "jackrabbit" starts - accelerate smoothly to cruising speed. Don't stick your foot in it.

Use quality gasoline. Not high-octane (that can actually reduce efficiency and economy on low-compression engine slightly,) but just stuff that won't have a lot of water and leavings in it. Spend a few extra cents per gallon to avoid the "discount" fuel - unless it turns over very quickly (Travel Plazas like TA, Flying J, and the like all turn over their fuel stocks about every two days...)

Do not fill up right after the tanks get filled! Fuel refiners use diatomaceous earth in their filter setups, and some of it will travel through to the trucks. The trucks will pump it into underground tanks. Let it settle, then fill up (three or four hours will usually do.) If you suck up a lot of that stuff, it will crap up your fuel filter (and could crap up your fuel strainer "sock," making your fuel pump have to work harder.) If you don't have a choice, make a note to change your fuel filter soon - it will help.

I've heard good reports from the field on switching to synthetics in the axles and transfer case - and manual transmissions. Reports from the field on synthetics in the AW4 are consistently negative (clutch chatter/slip, mainly.)

Ignition improvements? If the fuel system is doing its job, the ignition system will as well. You're already getting about 45kV to the plugs - that's plenty. I'd only suggest ignition upgrades if you were going to forced induction, or significantly increasing compression (like up to 11:1, say.) Even cars in the 1960's ran up around 11-14:1 with "can coil" ignition - and about half the spark energy.

Watch your cruising rpm - I've weighed in on this before (as recently as a half-hour ago.) Search, Grasshopper - the answer isn't what you think (I've verified my observations experimentally, and I'm really starting to wish I had kept my notebook from that little four-month experiment...)

Tyres. Make sure they're properly inflated on the road. You'd be surprised how much effect that can have...

Most of what you can do to help fuel economy really isn't in your engine - it's in the rest of the powertrain and in your driving habits. It can make a huge difference...

LOL! This is the reply 5-90 is speaking of. http://www.naxja.org/forum/showthread.php?t=926419

Not laughing at you btw, Just the fact that 5-90 is cruising the boards at this ungodly hour. And the fact that he seems compelled to answer questions of a certain type. Very knowledgable fellow, btw. He knows his stuff :lecture:.

jesterbomb said:

LOL! This is the reply 5-90 is speaking of. http://www.naxja.org/forum/showthread.php?t=926419

Not laughing at you btw, Just the fact that 5-90 is cruising the boards at this ungodly hour. And the fact that he seems compelled to answer questions of a certain type. Very knowledgable fellow, btw. He knows his stuff :lecture:.

Click to expand...

Eh. I keep strange hours to begin with. Throw in the fact that I can think more clearly when my mother-in-law is asleep (I know I'm not going to be bothered...) and the alterations in my brain chemistry from my roads incident in NOV2005 and subsequent treatment (massive subdural haematoma, among other injuries,) and it's not really surprising for me to be up and around at this hour. Hell, it's a good time for me to work on research for my books anyhow (currently 0415.)

Since a good portion of that research is online, I keep this open as a pleasant distraction. Between that and the constant correspondence with various manufacturers, I need something to "tune out" on once in a while...

Meanwhile, thank you for the compliment. I'm grateful that all I lost (due to the brain injury) was languages. I don't get paid to speak them anymore anyhow... My short-term memory is still a little flaky, but my long-term memory is virtually encyclopaedic - for which fact I'm also grateful...:read:

sjx40250 said:

This weekend I took the 90 out for a trip north, 180 miles one way. (lost my 97GC 4.0L from a rear end hit, typical MPG almost 22 on HWY). I used 3/4 of a tank on 350 miles (by the gage). I have never seen this before and I have owned it since new (now has 188K+). I attribute the improvement to the replacement fuel injectors about 2 years ago.
BTW it has a Borla exhaust, header to tail pipe. Other than adjustable map, removal of venturi in the intake between the box and TB,

as well as box intake hot/cold valve removal,

Click to expand...

fully stock.
Oh yeah, all mine are auto's

Click to expand...

what is the intake hot/cold valve? I know about the venturi but never hared of the hot.cold valve?

vacuum opperated flap that allows either engine heated air during warm-up or fresh air after opperating temp-- located on front of air bow.

only thing I would add to 5-90's thoughts would be get the best alignment you can afford and try to avoid potholes and curbs afterward. The same resistance from underinflated tires is created with well inflated tires pointing four different directions:spin1:

--Shorty

take out the crap...the lighter the load the better.... think twice if you really need those 80lb subs and those nuclear bomb supplies... For daily driving my xj goes down to the bear minimum... full size spare, basic emergency road-side kit, and a tow strap.... My buddy, however, insists on carrying around 2 full gerry cans, a FULL tool box, a regular jack and highlift jack, etc...easily 150lbs in supplies he will never need for the drive to work..

If you're running aggressive mud tires (eg swampers) consider swapping to a thinner less aggressive a/t or radial tire for street use.

Now I have noticed that at some speeds when I have the cruise set, I can downshift and feel the gas pedal raise up from the floor. Now I know it's running a slightly higher rpm but it is using less fuel right??

Oh goodie!! a MPG thread....just what I was looking for...=P

Seriously, though...there's a lot of things that you can do with your XJ. All hope is not lost.....just do some research, and don't buy into any snake-oil gimmicks without researching it first.

Might I point you in the direction of http://www.gassavers.org?? If nothing else, there is a lot of good info there, some very good ideas and people, as well. Beyond that, it gives you the ability to track your MPG, and see what other vehicles like yours are capable of. Head on over there, tell them RaccoonJoe sent ya, and check out the garage entry for The Rolling Brick while you're there, you'll be able to see what I've done to get my 20+ avg.

===============================
Do those tornado things really help?
==============================
May have help a few people in the days of carbs and wet system. With port fuel injection I got to see it for myself if anyone gets better numbers with one.
Timing: Bump if you CAN. But keep a ear out for that ping. No knock sensor right? Loud muff(s) will make this impossible. Remember your EGR system (if you got one) may not able to keep the NOs down with faster timing. Not a biggy just set timing back if you have your tail pipe snuffed by the state.
Engine MAY run hotter too. Hard to say for sure before you try it.

for me, i've simply lightened the load on the skinny pedal ALOT, just by doing that i increased mpg by about 4, sure i start out alot slower than anyone else, but in city i catch right back up, as for the highway i try and keep it at 65 (while everyone else does 80), and even though i just bought a set of 31" tires i run my stock ones 90% of the time, that right there helps alot. but what are the best add-ons for increasing fuel efficency (poor high school student cant afford gas at these prices)

Serveck, you've got the right idea. Changing your driving habits is usually the best thing for increased fuel economy. (not to be confused with fuel efficiency). Something else you might try doing......Drive as if you have no brakes. Start out slower, try to time stoplights, coast up to lights in neutral, etc....these things will all help increase your MPG.

jeepman121 said:

Now I have noticed that at some speeds when I have the cruise set, I can downshift and feel the gas pedal raise up from the floor. Now I know it's running a slightly higher rpm but it is using less fuel right??

Click to expand...

Maybe, since the ECU actually controls the fuel rate, and not the throttle it is not a sure thing. It is possible.