Sad news..... I'm not seeing any improvements in fuel economy. I guess others on this site already knew what my results would be, but I had to try. I installed the Volant Cool air intake, Calmini exhaust, removed the basket and air dam. Also installed manual hubs (because I like manual hubs and I'm not concerned about cost). I do have Yakima cross bars with the basket on top. I filled up after burning nearly a full tank and got 16.5 mpg. That's basically what I was seeing from day one. Well, maybe I was seeing 15. But if there is any improvement on fuel, it is not hardly anything. But, I do notice much better low end power and I like the sound when I put a foot into her to pass. So, don't do the changes for fuel savings. Do them for more power and or sound.
The truck does what I need it to do, so I'll live with the fuel situation. I've driven vehicles with worst mileage and some with better. Each one had its pros and cons.

is it possible that with those mods, you are just being tempted to hit that gas harder to get the sounds you like?

maybe if you try to use a whole tank without passing 2500rpm's and not flooring it you would see better results?

i also have crappy gas milage, but i want to do the same thing you did, just for fun and hopefully for some improved performance.

But you went out and spent money on your mods in hopes of better mileage?

Listen, it might take a while, but as you've noted, once you learn to drive w/ a more delicate touch on the throttle,you'll see a difference. Unless of course you just keep adding more weight. I.e.- Armor, bigger tires, bumpers, tools, etc It all adds up and slows you down

In purchasing these products, in the hopes of mpg, when do actually predict seeing this investment pay off (as in, saving said $ spent on products in the amount of fuel saved)?

How much fuel could you pay for with the money spent on the intake and exhaust?

I say drive the thing.

I never care about the gas price or the amount of times I fill up. It's nothing that complaining about it will cure or make better.

Just drive it!

I did keep my foot out of it during my test. It has only been one tank. I'll report for some future tanks. I kept the RPMs below 3,000. Slow take-offs. My drive to work is backroads, mostly 45 - 50 mph. Some in city driving, but not much. My thoughts on the mods were, if it improved gas mileage, great. If not, fine. I would be gaining some low end power and I like the "sound" of performance anyway. As to payback, IF it had saved me 2 mpg (didn't seem unrealistic at the time), that is almost 40 miles per tank. I drive 50 miles per day round trip to work. That is 250 miles a week, 13,000 a year. At 16 mpg = 812.5 gallons. At 18 mpg = 722.2 gallons. At 20 mpg = 650. So...
90 gallons less if I saved 2 mpg. 162.5 gallons less if I saved 4 mpg. So, $169.00 saved or $305 saved @ $1.88 per gallon. If gas goes up much higher, pay back would be quicker. I did the math quick this morning, but I think it is right. So, depending on fuel savings I was figuring around two years payback, with the added benefit of low end power during that period. As it stands, I might be seeing a mile improvement or so. Payback will be slow, unless the other benefits are enough for me, which they are. I'm just out a few hundred dollars parts. Had the fun of working on the truck. Shit, look at the cost of other cars people are driving. I figure for the thousands less I paid than say some kind of Lexus, I have lots of money left over for fuel. I like to experiment. Sometimes you win, sometimes not. To each his own is what I say. Plus, I drive my Harley year round and that gets about 50 mpg. Kind of offsets the Xterra some.

Cyclemut,
I did the experiment, spent the bucks and am nice enough to share my results for others. If I was reporting 4 - 6 mpg better mileage, I think people would be burning up the LAN wires ordering the parts. As it is, it appears we all must either learn to live with the mileage or get rid of the truck. I am disappointed in Nissan. Their sticker showing the predicted mileage is not even close. All other cars I have bought typically exceeded the sticker mileage. This truck does the lower mileage list in fine print on the window sticker. I think more people would NOT be complaining if the sticker showed a realistic MPG from the start. But Nissan would have a hard time selling these things if the big numbers on the window sticker said '12 city - 16 highway'. My Subaru Forester had 28 highway listed on the sticker. It got 28 mpg on the same drive I do to work that the Xterra gets 16. But the Forester was light weight and couldn't handle other stuff I asked of it. I can live with the Xterra mileage.

My mileage only went up from 2 to 3 mpg when I did the same mods, which was nice, but I am more impressed with the extra low end power I get than the MPG. I get a consistent 290 miles before the gas light goes on, but I do not get into the gas much of the time. When I do get into it my mileage goes down pretty fast, but I never get less than 16 no matter how I drive.

Possibly the resonator I left on the exhaust is giving my X the backpressure it requires for better mileage. I was getting 16 to 17 MPG before the mods and now I get in the low 19's to 20, but that is just a bonus, since I wanted the power, which was an amazing difference.

Tom

Tom, what resonator is in your exhaust system? You installed a Flowmaster muffler, correct? Maybe the Calmini system is different. Any ideas about this? Thanks.

I got improved gas milage with my snorkel, K/N filter, and exhaust....yeah only about 2 more a gallon. I went from 13-14 MPG to 16-17 Mpg...and thats lifted and 33's. It pays off in the end.

But, when I put my safari rack on top, like you mentioned about the Yakima, that hurts my MPG and drops it down 2-3 mpg...so I leave mine off all the time unless I'm carrying alot to an xcursion. I'm even thinking about just getting one of those rear hitch platforms to carry the gear and unhook it and leave it at camp when I'm wheeling. I don't have to worry about the wind resistance that way.

Hmmm. Maybe that is it. I definitely need my Viper bike trays all the time, so I can't take off the Yakima crossbars. I'm meeting a group tonight for a MTB night ride at a state park. But the basket is really for when I'm doing SCUBA. I like the look, but don't need it right now. Wonder if I removed the Yakima air scoop? That thing is probably pushing wind. I think I'll remove that first. Then try with no basket at all. Thanks for your input KCX.

That soup can thing on the end of the exhaust pipe that comes stock on the X is what I left on. I did not do anything to my exhaust except for replacing the GIANT stock muffler with a Flowmaster 40 and left the rest as it was.

I agree that taking the basket off the top will help your mileage, but you are trying to see if the intake/exhaust mod makes a difference with what you were running before the mod.

I have heard that removing too much back pressure will have an adverse effect on mileage because the motor requires a certain amount to run properly.

I did the mod for extra power and the mileage was just a unexpected bonus. The low end power boost is so nice I feel that alone is reason enough to purchase the intake and muffler for your X.

Tom

Tom, I'm guilty of not being real scientific with tracking all my changes. I suspect that when all is said and done, the mods have made a couple miles improvement. I may have posted my results too soon, but was trying to supply some feedback before others installed the mods thinking they'd see tons of MPG improvement. I need to run a few tanks as is, check my mileage, then make some changes to the basket and retest. I think the way all my mods went were like this....

1. Drove it stock. Mileage was like 15 - 16.
2. Added intake, exhaust AND basket, removed air dam and factory basket. Mileage is like 16.5 or so. So maybe the basket ate up what improvement I would have seen. Also maybe I need to run a few more tanks to be sure of the mileage. Then remove the air scoop from the basket and see what difference that makes. Then maybe remove the basket. If I save a few hundred bucks a year, that's some money for something else (scuba regulator tune-ups and such).

I'm not that worried about the mileage. I was looking for performance first, which I do see and am happy with. I am really just trying to report back to this site so others can benefit from the data and maybe help them decide if it is worth it to them to make the changes.

I agree with all of that and I was also trying to be of some help to others that were thinking about doing the modifications I did. The Flowmaster seems to be fairly simple and gave me a nice sounding exhaust with is what I wanted. The Volant on the other hand is hard to deal with, since it did give me more power on the low end and improved the sound-BUT!

It reminder me of Microsoft Software, where it could be great if they just finished what they started, but because of their interest in getting it out for sale as soon as possible, it isn't quite right.

There is no excuse for the parts not fitting and the lack of instructions just blows me away. It is difficult enough to install with the parts that don quite fit, but how the hell does Volant think people will get it done without instructions.

Anyway, it does what I wanted it to do and I guess I have dealt with more problematic instillations, but for the price it should be much better.

Tom

Tom, I wish I had read the posts regarding the Flowmaster before I purchased the Calmini system. I might have just done the muffler swap, which was most likely cheaper. Live and learn. Actaully I had not crawled under the truck to see the stock muffler. When I went to take it out, it blew me away how dam big it was. I could fit just about any muffler under there I wanted. Sounds like the best route is some type of cool air intake and replace the stock muffler like you did. But then you don't get that shiny tailpipe like with Calmini :-)

I'm shopping around to get the Flowmaster 40 Original installed on my X. Once I find a good deal on the muffler, I have a guy who will install in for $40 and hopefully it'll give my truck some much needed distinction. Think I will keep my stock pipes.

Can't wait! K&N filter's next.

drove mine stock from nc to fl and avg'd abt 16 mpg. did a 3" body and 3" suspension lift, w/ 33x12.50's and a gibson catback and k&n filter (along w/ abt 300+ lbs of metal w/ bumpers and winch) and went UP to abt 20mpg highway. i drive 43 miles each way to work...filled up less then a half mile from work, till i could see the gas in the tube, stopped at a gas station abt a mile from my house, and put 2.06 gallons in it (where i could see the gas). i dont know what else to tell you.