How do you make your own????????? and what are the gains??

 

im sure he meant nitrogen... nitrogen is lighter than air so theoretically it causes less rotating resistance which should result in better mileage

 

this might give you a tiny bit of info. its not on the 4 lit bit its on a jeep http://www.jpmagazine.com/techarticl...out/index.html

 

20xj00 got my back :P

 

I heard changing the tranny fluid lossens dirt in the tranny so you actually shouldnt change it if its after like 70K miles

 

because trans fluid has detergents in it to help clean the transmission. what guys will do though, is change the fluid, run it for a a little bit of time, drain it again and then remove the filter, put new filter in and then replace with new fluid. when dirt builds up, the new detergents will loosen up and contaminants, which can actually plug up a new filter if you put one in, and contaminate the new fluid. by draining the fluid and refilling without changing the filter will actually catch any of the old gunk in the old filter so it doesn't contaminate the new fluid.

you can change the fluid well over 70K miles, you just need to take precautions. if the fluid hasn't been changed in over 70K miles, i fear for your trans anyways

 

Ah, i see, haha thanks for the tip, ill do that.

 

Not really--im looking for MPGs--i have 250+HP with my mods and i dont even take it off road, i just need to get my mpgs back up and the article said chips dont help, unless i read it wrong

 

Is there a way you would suggest to loosen dirt before i drain it and put the new filter in, or do i just have to flush it out and pray?

 

This was extremely helpful, I had no clue, this XJ is my first automatic. I was going to do my tranny this spring and had planned on just putting in new fluid and a filter. I'll definitely give this method a try.

My tranny just hit 70k and I have no idea if it was serviced prior because I bought it used back in October. I hope I'm ok....

 

I thought the tranny filter was just the equivalent of a screen door on a submarine- keep the fish out. Seriously, is there any media in those things? Can they clog?

 

your XJ has 250+ horsepower?

 

just replacing the fluid itself will loosen up any garbage in the trans. but, like i said earlier, leave the old filter in and run it for maybe 1K miles at most, then drain again and replace the filter at that point.. it's just because when you add new fluid, the detergents haven't been used up and the fluid hasn't been worn out, thus making them much more effective. this process is basically like doing a flush.

i'm in the same boat as some of you guys anyways, i need to do that this spring as well, lol. the miles are creeping up there, so i have to get it done ASAP.

 

for an automatic they are excellent! you should be alright for the most part, as long as the fluid doesn't look like it got puked in.

i've never actually opened one up before. from what i understand is their media is a couple layers of screens that refine how much stuff can pass through.

 

Having used add-on performance chips in the past, I can say that they can add some power in the upper rev band on a high revving DOHC engine, at the expense of a power loss in the lower rev band and roughness at low rpm. All these chips do is influence the spark/fuel map. I can only speak for my '96 OHV (pushrod) AMC engine, the chip is utterly useless in there. The stock ECU is set for maximum mpg and efficiency (complete fuel burning = minimum emissions), so it's probably the best choice for max mpg, provided all else is stock and nothing fiddles with the air/fuel ratio. Power gain always results in less mpg. On tranny fluid change: They used to say that that on a hi-milage automatic tranny, old, dirty tranny fluid keeps the clutch bands from slipping and thus lets the tranny go on for longer before needing to be rebuilt, so it'd be better not to change it until it fails. But 70k miles ain't much for a (Jeep) tranny, so you should be OK changing/flushing/replacing it with synthetic fluid...