do air intake or spacers work in getting better milage if so how much

All spacers do is make the sellor richer! There is absolutly NO GAIN..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

from everything ive heard, intakes do and throttle body spacers do not, im not sure because i had both already on my jeep when i bought it, all i kno is im getting better millage with them and a header then a friend is with a stock motor

what kind of milage you getting do you have both

Dude special intakes are for putting MORE fuel into an engine...not less!
If you need better milage getcha a Yugo.
The only possible milage improvements could come from a good tune up. Adding stuff to the engine will not help milage.
If a silly spacer or a different intake would help milage the engineers at MOPAR would have designed them instead of what you have now. Gas milage is a critical factor in sales of all vehicles. Your Jeep is engineered to get the best it can do.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

i get around 12.5 in the city with a 4.0L, automatic trans, 33in tires and 3.07 gears, thats with a CAI, airaid throttle body spacer, and borla header and catback

Its funny to read this post cause i have a buddy that swears his mid range big time increased after he added a spacer. I really don't believe it.

Of course he swears he saw performance increases, he spent a bunch of money on it. <img src="/forums/images/graemlins/wink.gif" alt="" />

Cognitive dissonance rears its ugly head! <img src="/forums/images/graemlins/smile.gif" alt="" />

While I cant speak for throttle body spacers and cold air intakes, I do not buy into the theory that what is supplied by the manufacturer is the best and most efficient and there is absolutely no improvement to what they have supplied. Manufacturers are driven by the same principle that the aftermarket industry is driven, MONEY. They produce their vehicles to produce the most PROFIT, not the best gas mileage, longevity, serviceablity or any other principle. They also have to worry about EPA standards which may or may not be a concern of ours. In todays market, people will pay more for these improvements from the manufacturer, i.e. Toyota Prius, that they would not have 20 years ago. And MONEY is the motivator there too, the reduced fuel cost to the consumer. As this market develops, it will be interesting to watch the balance of purchase price vs. what the manufacturer will supply to help out the customers pocket book in the long haul and what the consume will pay to obtain these benefits. While TB Spacers and CAI's may not be the answer, there are things out there that DO improve some vehicle as supplied to us by the factory. Case in point was my old '78 3/4 ton Suburban 4WD. Stock it got a solid 9mpg. With the addition of headers, duals, aluminum intake and a Holley carb, the mileage increased to over 13 mpg. Interestingly enough too, after snatching the 350 out and installing a small block 400 with the same accessories, the mileage went over 14 mpg. So certainly, the manufacturers do not supply a vehicle that was "engineered to get the best it can do." Maybe it was the best it could do under the constraints of PROFIT and the EPA, but certainly not the best it was capable of. My .02.