Hey guys, I have a question for all those who know lots more than me. I'm considering purchasing and installing an air intake and exhaust, possibly K&N intake, and the exhaust I'm not sure, I will look into. Either way, for those of you who have one or both installed, how has this effected your MPG? I am hoping that by installing these two, the truck will more efficiently move air and create a better mileage as a result. Is this so?

Also, I heard that an air intake can cost up to $200, and im assuming the exhaust will be around the same price area. Do those of you who bought them feel that the price is worth the results, either in MPG or horsepower increase?

The 'Performance' Forum has many threads about this.

The most definative result of the discussions is that no one can really tell if it's worth the money.

I got a mile or two gain out of the combination, but nothing much, look on ebay for some flowmaster 40's or 50's, I beleive I got the 40's on mine. Anyway, I got mine on there for about 50 bucks then I took the muffler to a muffler shop and they installed it for like $35 or so, but the whole exhaust thing cost me like $85. I then got the K&N air intake ebay 50 series
40 series

Also do a search on the website about intakes and mufflers, I ran a 2 3/4 in pibe on the muffler

I've got both and haven't gotten any noticeable mileage gain or loss.

I'd do it again - better throttle response, slight power gain, and a nice throaty sound. Just don't go into it expecting major power gains.

You may experience the placebo effect but nothing more than that. I don't know if the extra power feeling is also attributed to the placebo effect or not but I say that there IS that little extra kick but nothing major. Don't expect fuel mileage gains.

I just installed a bruteforce intake. I can feel the difference. It's not much, but the throttle response is quicker and it has slightly more kick. Now if I can just find that vacuum solenoid I can complete the installation....

I've been toiling with doing the air intake and exhaust for months now. I've read all the threads on the site and everyone seems to have different opinions about performance gains. Many say noticible differences don't happen unless you do the exhaust along with the intake. If you do both, you're looking at about $600 ($190 for K&N genII intake and about $300-400 for new performance muffler and exhaust). It's alot cheaper if you don't do full exhaust replacement. I finally decided to go ahead and do it. It may not make huge gains, but it certainly won't hurt.

I have a AEM Brute Force air intake and custom maganflow cat back exhaust. i have noticed a pretty decent gain in hp and torque. as for mpg, i think ive gained about 2. i paid $220 for the air intake kit, and $225 for the custom exhaust.

Haven't been to this site in a while. Months ago I installed the Calmini exhaust and the Volant intake. Initially I saw no improvement in MPG. At the time, one thing that I did was NOT remove the baffle from inside the wheel well. Mainly because it was a pain in the ass to remove and I didn't realize what it was all about. All familar with the Volant intake know that the air box butts up against the inside of the fender where that factory baffle opening is. It uses that baffle hole and a hole beside the baffle for intake air. What I found out when I removed the baffle last weekend is that it is just a big sealed container. So, basically it has been blocking my incoming air. So, I got that puppy out of the wheel well. Also took my saws-all and cut so that the two holes in the side of the truck are now one big hole for air into the Volant box. I have already noticed an increase in MPG. Maybe as much as 2 MPG increase. So, my conclusion is that the Xterra factory air box starves the motor for air. And if you don't remove that baffle from the wheel well when installing the Volant system, the engine is still starved for air.

Anyone doing this kind of mod HAS to reset the ECU otherwise any changes in MPG will not be apparent for some time.

Disconnect the battery and depress the brake pedal for 30 seconds or so.

I just checked back in. My ECU was reset at the time of the mods. It made no affect. The only thing that made a positive change was when I removed the baffle and made the hole as big as possible through to the fender well so that the Volant was getting as much air as possible. That definitely made a difference to anyone out there doing these changes.

I installed a K&N 3 years ago, an exhaust 2 years ago. I keep anal mpg records, and seemed to have gained 2 mpg with the aircharger, nothing more with the exhaust. I also noticed I lost 2 mpg during the winter months (compared to previous winter average)

To early to tell, but I finally cleaned my filter, and it seems my mpg jumped up from my norm (only over 1 tank so far)