my osiris economy tune got me 32 on a trip to KC a few weeks ago.

 

I got 32 mpg in my Z once, and it was actually kind of hard to do but only because I have a base model with no cruise control. I've tracked nearly every fillup with my car since I've bought it last year and average out around 20 mpg. I also track the trip meter MPG and compare the two. The difference is usually less than 1%. The greatest difference I observed was an outlier of either 3% or 5%, due to a sudden change in driving style very shortly before getting gas (for example, 300 miles on the freeway, then 20 miles in the city).

I average out to about 20 mpg, to a peak of 32 (observed on trip computer) and a low of 13 (also on trip computer).

Now that I have the Technosquare F-Tune (on an otherwise stock Z) I'm keeping an eye on mpg, but it doesn't seem to have made a significant difference.

That's assuming he drove until the tank runs dry. There's a 5-ish gallon reserve and assuming he gets gas the moment the gas light turns on, it's 32 mpg.

 

all you people are talking about cruise control this cruise control that...when cruise is NOT necessarily the best way to increase your MPG. It would be if the roads you're on are flat, but cruise control cant anticipate hills, so it floors it up hills to maintain the speed that you set the cruise at. I understand why you use it etc etc, but its not the best for MPG

 

I do what ms350z said.

I bought my z with 34km on the odometer and a full tank of gas Feb 2009.

I've kept track of every litre of gas thats gone in the tank. Up to 8972 kms at last fill and averaging 9.81 km/litre (27.71 mpg) about 90% highway at 110 kph and 10% city driving.

My last fill was 63.92 litres for 650kms travelled which equates to 10.17 km/litre or 28.73 mpg. My computer usually reads high 9s to low 10s km/litre which I reset every few tankfulls and is close to my manual calcs.

Getting its first outing on the track in February so that will change things a bit.

The speedo reads slightly fast if my gps is anything to go by. 110 kph on the speedo is only 105kph on the gps. Absolutely stock 6mt.

 

Solidfish-if you saw 999mpg on your gas mileage, you must have been viewing real time gas mileage and not avg gas mileage. When viewing real time gas mileage it will show 999mpg when you are coasting because the injectors on many modern cars actually shut off while coasting, hence infinite gas mileage. I have a Scangauge II, and it shows 9999mpg when coasting, and the manual explains this as mentioned above.

Boogshag-You are right, cruise control does not ALWAYS yield the best gas mileage. However, many of us do live in relatively flat areas and keeping the cruise control on while driving on the interstate does yield an improvement in gas mileage.

 

 

32.3 mpg @ 63 mph average with HKS GT S/C....

 

Yes, I tend to agree with this as well. I'm not as good as the cruise control at holding a steady speed. Too frequently I realise I have either sped up or slowed down through lack of constant concentration. The cruise is more relaxing and holds right on the desired speed and being a manual I just leave it in 6th. Over all I am of the opinion it yeilds slightly improved fuel economy. I'd get better economy but every now and then or when on a passing lane I end up booting it (bye bye petrol).

 

yes you are both right, as long as the area is pretty flat, cruise is definitely more consistent than your foot. living in iowa/nebraska/kansas or something would definitely apply haha

 

I just realized you live in New Zealand haha! I know nothing about it!

 

my computer says im averaging about 23mpg. Thats good considering everytime i leave college im so happy to get in it and leave i drive it as fast as possible lol, maybe the slow trips going to school and to work even it out haha

 

I have personally gotten 51.2MPG

look http://photos-a.ak.fbcdn.net/hphotos..._1384583_n.jpg

 

I would beg to differ that the cruise control floors it to gain speed. In my experience it is much more subtle than that on the 350. I typically even use the accel button to increase my speed on the highway as it is pretty gentle. That said, I get around 28 on the highway and 20 overall. 12 on a track day.

 

First of all, the Z has a 16 gallon tank. Secondly, that has nothing to do with the calculation for MPG. It's total number of gallons put into the car that you use to divide your mileage. You'll never put in the full capacity because it's impossible to use every drop of gas in the tank due to the reserve.

 

correct, thats why I like to reset the TripA meter after each fillup. Just divide the total miles by how many gallons I put in at the next fillup.

 

According to the owner's manual, the Z has a 20 gallon tank... I have personally put over 16 gallons in the tank when the DTE was still indicating I had 50 miles or so left. But... nobody will ever be able to put 20 gallons in their tank unless they drain the tank first, as the car will stall from fuel starvation before it ever uses all 20 gallons. You are exactly right saying that it is the miles traveled since last fill up divided by the exact number of gallons that it takes to fill your tank that gives your mpg. I'm not sure why folks have such a hard time with this?

 

20 gallon fillup?? no way. I've ran on fumes before (or what seemed to feel like) and the most it took was 15 gallons.

 

Did you read anything I said? I said the tank holds a total of 20 gallons, but you will never be able to put that much in the tank because even if you ran the car until it stalled out for lack of fuel there would still be some fuel left in the tank. However, unless something is wrong with your fuel system (such as the recall/TSB regarding this), you are not "running on fumes" if it takes only 15 gallons to fill up.

 

ya, i was agreeing with you. 20 gallons is no way!

 

Gotcha, guess I misread what you were saying