I've had the XERD headers, K&N Intake, and Borla TD exhaust for a while now and I am certain my gas mileage has improved significantly - just wanted to be sure I wasn't being dillusional before posting it up.

When I traveled to northern Ohio from Lexington, KY, I had reset my avg speed / fuel efficiency meter and by the end of the trip I had the following stats:
Avg. speed: 78 mph
Fuel economy: 29.5 mpg

This was for the entire trip.

I recall that before the mods, unless I used cruise control at around speed limit (65-70 mph), the fuel economy did not climb anywhere near 30 mpg.

Also, in city driving, I used to average 15-16mpg, but now I have not seen the efficiency drop down below 21. Driving style wise, I am driving with a similar aggression level as before, if not a bit more aggressive.

I am quite surprised that fuel economy was affected this much by better air flow.

 

was the road trip downhill? check the elevation stats of both cities. cool though.

 

According to an elevation map, the entire route fit in the 1000-2000 ft above sea level category.
http://www.nationalatlas.gov/relief.html
Elevation may have still been a small factor but the experience I mentioned with cruise control at speed limit was actually on a trip to the same destination up in Ohio.

 

yeah, this is really a result that I would assume with mods. Nice addition to the already added benefit to more performace. Better breathing should lead to more efficency.

 

I've been really surprised at how fuel efficient our car is.

 

No I meant the difference in elevation between the two towns. Meaning, did you travel downhill? Yes, I agree, our car is fuel efficient especially at the RPMs it turns at speed.

 

I thin the Z stinks on fuel honestly..how its an LEV I do not know. But, after my headers and Y pipe install (already had the cat back), gas mileage went up alot..I am now going about 330-340 miles between tank fuls (filling up usually around 16 gallons)

 

Guess, coming from a truck, the Zs mpg was incredible, lol.

Hey igor@af, real nice group buy on the Teins there, seems like you will have a hard time getting that many people to buy them in that short of period of time. February 1st is quite soon.

 

Rodney,

I posted the GB yesterday and already had several serious inquiries. Weekends are much slower on AF than weekdays, so I don't think we'll have trouble reaching a solid number. So far there are 2 entries (including myself).
The good thing about the GB is that there is no minimum - so anyone who signs up will get at least 20% off retail, which is over $100 cheaper than anything I've seen on the web ($1488 + $45 for 350Z Tein FLEX).

 

Remember that perfect combustion would yield only CO2 and H2O. Therefore, a car could guzzle tons of gas and still be LEV as long as it burned it cleanly. The LEV only checks for things other than CO2 and H2O (and in most cars, the LEV status is governed in a large part by the fuel lines, and seals, since non-LEV cars pollute more standing still than an LEV car does when it is running).

Also, I'm getting 24 MPG in mixed driving (some of it "spirited" on twisty mountain roads), so the mileage can be decent if you are careful. Plus I have 30,000 miles on the car now which has probably loosened things up a bit.

-D'oh!

 

Wind can also factor in gas mileage. This time of year a 10-20 mph sustained wind is not uncommon. Driving style on the highway will also influence, like whether you do much truck drafting, working with lots of high speed traffic, etc. At that average speed you were probably doing lots of passing. BTW that's an incredible average speed when factoring in slow downs, fuel and rest stops, traffic, occasional speed trap, ......

 

My dead stock Z pulled off that same exact mileage on (~29.5) on a road trip from detroit to dayton and back to detroit.

 

My totally stock performance model got 27.5 mpg driving 80 mph (trip average was 71 mph including stops & traffic) on an 1100 mile road trip. 29.5 is definately better. By the way did you use the trip computer or calculate it your self? I find the trip computer is within about .5 mpg of what I get based on the gas pump.

 

I used the trip utility that we have in the car.

 

Interesting, extend it out 2 more weeks, and you will probably have a 3rd, which is me.

 

The GB appears to be going really well - I am getting flooded by inquiries. Hopefully these people that ask me all these questions are actually calling in to join the GB.