my computer show around 15l/100km and now i have 6k km on it, i wouldnt worry coz it's still new, it will get better after 20k km, that's also when the car is in best shape. but i dont think you should be using 89 octane, may be you cant tell the difference now, but as long term it's not good for the car !
and for the first time dont use sythentic until you have 10k km on it!

 

I have 12000kms on mine and I get 16l/100km city.

 

i just did a little experiment this week to see what my mileage was. i filled up my tank last week and reset my trip, when i hit the halfway mark on my fuel gauge i filled up again. to my surprise i got 297.2 km's. my receipt shows 34.085l's on fill up. that calculates to an average of about 11.5l/100 unless i did my math wrong. i drove very conservatively and shifted between 2k-3k rpms for the whole week. on the hwy i kept it under 120km. i've got about 7500 km's on my car and i would say my city/hwy driving mix was about 85/15% this passed week. looks like with conservative driving i added about 40 to 50km's to my overall distance. usually i get around 240km's before i fill up. i guess nissan wasn't lying about their stated mpg. then again who buys these cars to drive them like a prius??

 

KJO,
650 kilometers on the same 65 liters isn't bad, and for that speed of 140kph, is quite good...that calculates out to about 28.5 mpg's.
You could probably do over 30 mpg's at a steady 100kph.....(I know my '03 Sedan would. My coupe wasn't quite as good, but nearly).
Unfortunately, city g/mileage is not our G's forte, and when you add in a tight engine, and proper breakin procedure into the equation, it nets you perhaps abnormally poor mileage.

Having learned a little more about your situation, I doubt the dealer will want to 'adjust' anything, since it seems to be running so well.

Enjoy, and let us know how you do.

Colin

 

kjo..your mileage sounds pretty good. I drive more highway than city and have 17,000 kms on my 05 G35X. I average 11 to 12.5 L/100km per tank since I got the car. The very best I have got so far is 9.8 L/100km on a tank.
I will be able to give it a good highway check when we travel to our east coast meet .
Wayne

 

When im not constantly ripping on the car, just occasionally, i get aroudn 12.5-13.5L /100km in the city, this is using shell v-power in Calgary 91oct, and Chevron permium 92 in Victoria. On the highway I have gotten it as low as 8.1L/100km from the drive from Calgary to Victoria and vice versa, but avg about 9.0L/100km driving relatively fast. At this rate, my nav tells me I'm getting a close to 830km per tank of gas!

 

Whoa...good stuff, what car is this with??

 

04 G35C 6mt, only mods that *may* have effects are y-pipe, res-test pipes + sparkplug non-foulers for o2 sensors, z-tube + k&n.

Somethings i have noticed is sometimes if u excel quickely to your desired speed, it will be better on gas then slowly/normally driving to yoru desired speed. This is based only on the info given from the nav.

I also noticed that when using Chevron Ultra 94, the car just burns it really quickly, and end up getting worse gas mileage. Although 92 octane seems perfectly fine, i dont notice any performace gains from 94 on my particular car (dont detect any timing retard) , but at sea level it could have some benefits in the hot summer mths and long/continous wot runs.

 

It's interesting you said that the car got worse mileage with 94.
I have noticed that my mileage seemed to drop when I switched to Sunoco 94. Most of the time I use 91. I don't think I am going to bother treating the car to 94 when I can get it. All it seems to do is make my wallet thinner.
Wayne

 

I got worse mileage with 93 octane than I do with 91. I thought it was a fluke at first but it was consistent for like 4 or 5 tanks.

 

I recently bought a 2005 G35x. Have put on ~4500 km in 2 1/2 weeks (!). I've checked the mileage 3 times, and have consistently obtained 27 mpg (10.4 L/100 km). Mostly highway, occasionally in the city. Most recent fill-up, I went 662 km on the tank (78 km after the low fuel light came on), and it took 70 L to fill.

For those "doing the math", this might be a useful link:

http://www.tdiclub.com/misc/conversions.html

Mileage issues aside (it's OK, really), am enjoying the car.

 

I can never get it to fill past 63L-65L of gas, even after driving a bit with the gas light on, i think it's the averaging algorithm used by the nav. I think once the nav reaches " --- Distance to empty", as in less then 0, there is approx. ~100km left of gas for regular city driving, and probabaly about 50km or so if you have been on the hwy for that entire tank of gas. This is proabaly due to less fluctuations in readings from stop and go traffic, therefore the readings would be more accurate.

 

Hey Mac, thanks alot for the link, I have been looking for one like that.
If you just want Metric Fuel Calculator, this is the one I use:
http://www.csgnetwork.com/gaskpl.html

 

YOu guys all seem to be doing better than me. I'll have to start monitoring mine again so I have a current picture of my fuel economy.
Thanks for the conversion calulators mac and Wayne.

Deane

 

That should be interesting to compare the G35, G35X, & M45