How to get more MPG out of a 4.0L?

[Matmadus]

I was wondering what's some go way to getting a couple more mpg out of a tank in a 1994 YJ with the 4.0L :?: Seeing I'm thinking of staying with this engine other then switching to a diesel. i want to know how to save some money. I get 550 KMs to like 68 litres of gas.

But seeing my exaust manifold has i nice size hole it it, I'm putting of a set of headers, mainly because I'm doing the work myself and If i'm going to fix anything i want to do it right the first time. So there going on in a week or two. Other then that it's will be mostly stock. Have to chance a couple sencors. but that all that's wrong it it right now. but thought while i have it in the garge what else can i do to save money on gas to get back what i lost fixing it. so Any info/help will be great help.

Also any good suggusts on a good set of headers for a stock exaust? I'm putting on a aftermarket in the spring. so it will have to last till then.

Thanks for your Help

Matmadus 8)

 

[southtj]

new torque converter?

I get 550 KMs to like 68 litres of gas.

You might need to translate that for us. Remember...we Americans revolted against the metric system and don't know our Kilometers from our Centimeters.

 

[avyoung]

A few things that come to mind. K&N air filter high flow exhaust like headers, high flow cat, and muffler. More air pressure in tires. (less resistance) That is all I can think of for now. Oh you can buy a Metro, I hear they get good mileage. heheheheheehehhehehehhe

 

[Matmadus]

Sorry i forgot, i get like 345 miles to like 18.5 gallions of regluar gas

 

[Bounty__Hunter]

Airtube and conical K&N filter will help, I use www.rustysoffroad.com for that and cat-back Flowmaster exhausts, best prices around.

Also change your driving habits, accelerate slower from a standstill, shift sooner, and drop your highway speed by 10mph.

 

[Bounty__Hunter]

Almost forgot, change the mechanical engine fan to an electric one, you'll free up a few HP and mileage will improve. I'd get an OEM fan from a Ford Taurus or similar donor vehicle, they last forever.

 

[Green97TJ]

your getting over 18 mpg and complaining? :shock: LOL ill trade ya!

Haha.... anyway, i understand why your wanting more, i would too..... but everything i can think of has already been suggested! The rest of them are to smart and im too slow!! haha....

Nathan

 

[graewulf]

something to consider.. tire size.. the bigger the tire the lower the gas mileage....

 

[Tug-n-pull]

Coast down all hills! hehehe Tug

 

[jeepdude832]

I put a banks torque tube, banks stinger, k&n, tornado fuel saver, jet performance chip, and snorkel. Thats a lot of money though. If your in europe wich I am guessing that you are gas isnt to cheap either. 18 miles a gallon is still really good though. Thats what I get sometimes but I like to zip and weave and I go offrroad a lot

 

[Craig]

Depending on the size of tires you're running, having the correct gearing for them will make a huge difference in gas mileage. 550 kms to a tank sounds excellent to me, I only get around 500 kms to a tank.

 

[Bounty__Hunter]

Don't forget, if you have larger than stock tires and haven't corrected your speedo, your mileage will be off. It will be off the same percentage that you increased in tire height.

Once you regear your speedo for the correct tire size and gear ratio, you can correctly figure your mileage. Otherwise, calculate the percentage of tire size change into your mileage.

 

[wm69]

Hey Jeepdude, don't think Canada is in Europe (sorry couldn't resist) :lol:
As for a brand of header, Borla headers are expensive, but they also have a lifetime guarantee, and they're stainless so they don't rust (guess that's why they guarantee them). I've got one on my jeep and love it. Doesn't make sense to spend that much on a header unless you are planning on keeping the jeep forever though (I'll be buried in my jeep). I just say a couple of guys who had holes rust in theirs over time and it's a Pain in the A$$ to replace one. Kinda like axles, you can spend twice as much and never worry about it again, or spend 1/2 as much and you'll probably be fine, but you'll wonder when it will break (and someday it will)

 

[Snitty]

another thing on the tire size/mileage issue.... you don't ALWAYS lose efficiency with larger tires... if your engine can easily turn a larger tire, you will actually increase your efficiency due to the fact that you will not have to turn the wheels as many times to clear a certain distance. the circumfrence of the tire makes your axle:distance ratio... you can increase your tire size, and it will help with economy UNTIL the point of straining the engine... it is the same principle as axle gearing

 

[graewulf]

another thing on the tire size/mileage issue.... you don't ALWAYS lose efficiency with larger tires... if your engine can easily turn a larger tire, you will actually increase your efficiency due to the fact that you will not have to turn the wheels as many times to clear a certain distance. the circumfrence of the tire makes your axle:distance ratio... you can increase your tire size, and it will help with economy UNTIL the point of straining the engine... it is the same principle as axle gearing

exactly.. but most jeeps are geared for at most a 235/75/15 from the factory unless you got a towing package... newer jeeps anyway...

 

[jeepdude832]

Which spark plugs

I wasnt paying attention to your location I asssumed you were a brit or frenchie cause of the kilo thing sorry.

 

[slab42]

Bigger Tires doesnt mean better gas milage, in the city, it takes alot of gas to stop and start a jeep with bigger tires (unless you have changed your gearing) The larger tires will help on highway gas milage (unless you lift it too much, then wind resistance is greater!)

 

[LadyJeepFreak]

Can someone explain a bit more about the K&N air filters to me? Do you just replace the stock one with that or do you have to replace other parts too, along with the air filter. This upgrade has been mentioned to me many times lately and I am interested in it but don't know much about it.

Just wondering, anytime is a good time. Thanks!

Lady

 

[jay79cj7]

I believe that you can buy the K&N filter that is shaped to drop right into your stock air box, but there are also kits to replace the whole air tube and put an conical filter on the end. Not sure which way is better, but the first option would definitely be easier.

 

[laneiac]

Can tell u one thing, if I was getting 18 mpg, I would be ecstatic, and not worried about more, cause u know newton.....