I installed a Z-Tube into my car about 3 days ago and I have been monitoring my gas milleage very closely with my Navigation system. I do mostly back road driving(60-70% back road, and the rest is highway).

My average has been a very consistent 23.7 MPG combined over the past several months, during which time I had reset my economy gauge 5 times. The highest of any of those measurement intervals was 24.2 and the lowest was in the low 23's.

After putting in the Z Tube and resetting my measurement, then driving for 3 days in the same fashion that I normally do.... Here are the initial results over the course of about 150 miles driven:

First day: 27.7
Combined total through 2 days: 26.8
Combined total through 3 days: 26.5

The highest I've ever had my car go for more than one day was about 24.5, prior to the Z Tube. I noticed that I get much better highway economy on a fairly consistent basis with the Z-Tube in at cruising speeds.

I'm now often able to sustain 27-30 MPG on the highway at about 70 MPH, whereas the stock intake seemed to give me about 24-26 MPG at that same speed.

My initial conclusion is that the Z-Tube appears to have a pretty huge effect on fuel economy... somewhere in the vicinity of +2.5 MPG combined, which equates to a gain of about 9.5%. I am also running a K&N drop-in filter. I highly recommend this mod-combo to anyone who hasn't already done it, not to mention that the car screams a lot louder at high RPM's now.

 

sounds good , i was pondering which intake to get and you seem satisfied. what is the part # for the k&n drop in (off the top of your head)??????
thanks

 

http://www.autoaccessconnect.com/inknairfi.html

I bought mine and the air-filter recharge kit from that site. They seemed to have the best combination of price for the cost of the filter/recharge kit/shipping. They also had the Formula 303 Aerospace protectant that I wanted to buy for use on my door seals, so I threw that into the order and saved some extra shipping money by packaging them all together.

To answer your specific question, the part number is: 3320312

 

ok Z tube used price has been raised to 70 shipped ( better gas mileage)


J/K but thats preety cool

 

Here is a pic of the stock G35 Intake Tube(or G-Tube, if you will).

Notice the onoxious sound baffle that shoots downward into the engine bay by about 10 inches, and the semi-rectangular box that disrupts air flow near the center of the unit. This thing reminds me of an old Transformer toy, more than an intake pipe.

 

FYI....I have a slightly used Z Tube and K&N Filter (just cleaned and re-oiled) that I no longer need......and I'm in Roswell.

Shoot me an email if interested....@

Tradebrand@charter.net

Terry B

 

Where can you get the Z tube? Do you have to get it from the dealer (part number?), or is there someone making it as an aftermarket part?
How did the Z tube influence performance? If it felt like it was improved was it measured or was it seat of the pants. I know if you make a car sound louder people will think it is faster so it would be great if you had some measured values such as 0-60 times.

Thanks
Francis

 

http://www.courtesyparts.com/infiniti/index.html

 

i got a used K&N filter for sale...PM me for those interested

 

No offense, but I have a hard time believing that the Z-tube can change the fuel economy by upwards of 3 mpg... Besides, why would the 350Z and G35 have the same EPA ratings if that tube helped so much?

Not flaming, just saying it doesn't jive with common sense.

Be sure to use calculations from receipts based on gallons in/miles driven... not just the computer. I wonder if there is something else going on that would cause the computer to mis-read the mpg calculations.

 

the computer takes time to relearn...the only way is to measure miles vs gas bought and not use the trip meter

 

Z tube alone would not make a 3mpg change. Perhaps .5 - 1 mpg at most. Other factors would have to contribute to 3mpg - driving speed, weather, terrain, trip lengths etc.

 

That sounds reasonable.

 

+1. I do not doubt your numbers. Is it possible that the car is running lean? Once the ECU “learns” the new mod, it will signal the injectors to add more fuel decreasing fuel mileage. Maybe.

 

^^^ Totally agreee with Deane