Better Gas Mileage

[Bulldawg]

Since I'm going to be using plenty of gas on the upcoming trip, I was looking at a few mods that definitely increase horse power, but how are they for gas mileage?

I've read the threads on Jeeps-Offroad about TB spacers, and how given the correct set up (exhaust to intake) can really increase some horsepower. I have also read that better exhaust, TB spacers, and a larger TB will help on gas mileage as well as increase HP.

My main question is, I'm not too concerned about upping the HP right now, if that happens, then kick arse! But would upgrading TB, TB spacer, K&N Air Filter system, and exhaust really improve my gas mileage?

[michaeljr5]

I know for a fact that a cold air intake will increase you gas mileage. It improved my Dodge from 16-17 up to 18-19 on the highway. They only take about 20 minutes to install.

[Bulldawg]

Just doing some numbers, if I can increase mileage by just 3mpg it would be a savings of right around a hundred bucks with gas figured in @ 2.35 a gallon for every 5,000 miles. +I'm not sure this is possible though, thats why I ask all of you smart folks!!! + ;D

[Jamakeit]

put some extra air in each tire, it will ride a little harder but it will up the mpg, how much you're jeep weighs is another issue to keep in mind.

[Snowman]

I know for a fact that a K&N intake increased my mileage from 21 a gallon to 23 in my stock TJ. This unfortunatly was on east coast 93 octane, but an increase should be detected no matter what gas is used. The best mileage for the buck would probably just be a replacement K&N filter instead of an intake. Exhaust mods will give a little mileage, but cost increases quite a bit. One of the best ways to up mileage i've found is just drive a little slower, usually 65 is the fastes I can go with out causing my mileage to decrease. Hope this helps.

[4x4_MMMH_4x4]

put a 2x4 under your gas pedal... helps alot actually... they were selling them on ebay for some time...

[madmax]

Come drive my Dodge V-10 then you'll love your gas milage. :(

[mousee]

install some highway tyres and overinflate 'em. Buy premium fuel and stay off the pedal as much as possible. that all should increase the mileage well over the 3mpg your looking for :)

[AK20]

Just doing some numbers, if I can increase mileage by just 3mpg it would be a savings of right around a hundred bucks with gas figured in @ 2.35 a gallon for every 5,000 miles. +I'm not sure this is possible though, thats why I ask all of you smart folks!!! + ;D


Is buying a K&N FIPK kit for 200 some odd bucks worth saving a hundred dollars in gas???+ Personally no its not, especially when Uncle Sam is footing the bill for the move and you'll most likely MAKE money on your drive...unless you stay at the Hilton and only drive 250 miles a day. Just my personal opinion, just don't drive like Dale JR, keep your tires properly inflated and you'll be good ;D

[Bulldawg]

To me, it is worth it if saving $100 is every 5,000 miles. That will be put on it, just on the drive alone. So after 50,000 miles that would be a savings of $1,000. I know uncle sam is paying for the trip, but why not try to get every bit out if it that you can?

I'm getting free gas on the way down there anyways, with the Miles of Freedom plan, I get the check card with $2,367 on it just for gas. BUT, if i can save money in gas, increase a little HP, and just be one more cool mod to throw in it, then why not?

Atleast something like that does pay for itself... eventually... ;D

[michaeljr5]

I have a cold air intake here if you want it. It's for a Dodge, but I'm sure it'll fit a jeep.

[TJVigilante]

The intake needs to attach to the intake manifold and bend in a certain way to keep from hitting anything....so I doubt a Dodge intake would fit on a Jeep 4.0.

I'd advise against the intake anyway, a drop-in replacement filter would be your best bet. The intake flows more than enough air for the engine anyway, you're not really going to notice a sizeable amount of power increase. Every vehicle is different, some may gain when others don't, depending on the engine they have. The 4.0.....not one of those engines.

[pyrotmaniac]

LOL I just did that long trip. From Ohio to Washington then north to fairbanks. 4775 miles. I think that all those ideas are more or less true. Dont forget though that just rutine maint. will improve your milage sometimes even better than what the factory publishes for your vehicle. then there are other times that you can drop 500 trying to get it to what the factory says it sould be and get nothing back. My suggestion is to upgrade your coil's if you have the old style HEI ignition then change your spark plugs and wires. with more energy moving through the pluggs you can increase the gap and heat range of the plugs. I went one step up on the camaro I finished last year. One of the things people often miss when upgrading the electrical system is the ground. I like to ground both heads to the frame. I cant say weather it helps or not but it feels like the right thing to do and costs a lot less than some of your other suggestions. I hope it helps thats just my two cents

[TJVigilante]

I was just thinking about you and this thread today. In the future, you may want to see about investing in an electric fan. This takes load off of the engine so it frees up power and gives you better mileage. I can't believe I didn't think about it before.

[Dan]

EPA Boosters, in "Bang for Buck" order:

K&N Intake: Worth every dime. 2 mpg/20-25 hp
MSD 6A Ignition: Great for 2 mpg/10 hp
High Flow Cats: Dunno...just took mine off and got 3 mpg/15 hp
Ceramic Headers: Reduces underhood temps 30% & unrestricts exh. 1-2 mpg/5 hp
Pulley Set: Real cheap hp/epa if your rig doesn't utilize the extra cooling/electric power

I've actually done all these mods. They work. Some not as well as the manufacturer claimed, but these are the one's still worth doing. Only catch is all were done on a V-8. Results would be slightly less impressive on a 6 cyl, or better on a 10 cyl.

[TJVigilante]

I'd be very surprised to see a K&N give anywhere near 20whp peak on a Jeep 4.0, maybe down low before the peak but not up high. The test for the K&N that gained 20whp was on an LS1 with a very restricted stock airbox, so I'll go with that one. Most applications though don't get much more than 5whp, nothing at all to speak about and within any normal environmental variables. Alaskans have about 5whp more than people with similar mods in the Lower 48 due to average environmental temps, and that's if you're both at sea level.

[Dan]

So why do most rigs get worse EPA in the winter up here? My 88 5.0 Mustang had a very restrictive (through the wheel well), was in Denver (mile-high atmosphere = uses all the air it can get), and was 20 hp increase, not whp increase.