The G35x certainly gets better mileage than my '91 M5 did (lucky to get better than 17-18l/100km around town in that behemoth). The last picture had certain columns hidden, if you want all the data (yes, I'm a bit retentive) here's a shot of the full SS:

 

Whoa Amazing records.
That is very impressive bookkeeping .

 

I feel better now, I thought something is wrong with my car. I get 13-14 in city, short trips, lots of idling in traffic.

 

+1 It's also interesting to note that the best fuel economy above consistently came from higher octane gas.

Years ago I kept a manual log book in the car but can't be bothered with it now. Unfortunately I think I'll have to start something like this with my new business.

 

Yeah, that's one of the first things I noticed Deane. If 94 was available here, I would definitely buy it. A little OT, but when I was in Portugal last month, the lowest octane there was 95 and and their premium with 98. I don't know if they measure octane differently over there but I was surprised to see it that high. I never noticed that last year since my rental was a diesel.

Anyways, that's an awesome log you've got going there Anthony.

 

Thanks for the kind words on my compulsive data gathering. My analyst says I need to lighten up a bit... Notice you can't spell analyst without ****...

I doubt the higher octane had too much to do with it since the addition of octane happend well into the trip with Calgary gas (91).

FWIW, here's a snip from Wikipedia about octane and part of the reason European numbers show higher. We use R+M/2 in Canada:

Measurement methods
The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing these results with those for mixtures of isooctane and n-heptane.

There is another type of octane rating, called Motor Octane Number (MON) or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and even deliver 98 (RON) or 100 (RON).

The octane rating may also be a "trade name", with the actual figure being higher than the nominal rating.[citation needed]

It is possible for a fuel to have a RON greater than 100, because isooctane is not the most knock-resistant substance available. Racing fuels, straight ethanol, AvGas and liquified petroleum gas (LPG) typically have octane ratings of 110 or significantly higher - ethanol's RON is 129 (MON 102, AKI 116) reference[2]. Typical "octane booster" additives include tetra-ethyl lead and toluene. Tetra-ethyl lead is easily decomposed to its component radicals, which react with the radicals from the fuel and oxygen that would start the combustion, thereby delaying ignition. This is why leaded gasoline has a higher octane rating than unleaded.

 

LOL, good point!

Also, thanks for the info on the octane differences in Europe.

 

No worries.

Now, back to my audiophile madness. As I type this I'm well into listening to the same track on "Nightfly" for the 20th time, trying to nail the VTA on my turntable.

How many times can you listen to Ruby Ruby before you go mad?

 

So tell me what you guys are getting (in #/100km please) for your 2007/08 G35x. I'm afraid I'm consistently getting 15l/100km in the city while 8 on highway.

I've yet to drive in the snow or the wet as of yet - well actually this evening and scrared the crap out of me when my economy showed 20l/100kms. Anybody experiencing this with the x's?

2007G35x

 

I average about 11.5 L/100km with the majority of my driving on the highway. This is my average over both.

 

Do you mind posting a downloadable copy of that spreadsheet or a link where you picked it up if you didn't make it so I may start one?

 

Do you mean me? I made the SS myself - send me a PM with your e-mail and I'll send you a copy.

 

Average 11.5L/100km - 87 Octane gas (Husky/Mohawk): 98-100% City
Average 14.5L/100km - 92 Octane gas (Husky/Mohawk): 98-100% City

All Time Low 20.2L/100km - 87 Octane gas (Husky/Mohawk)
All Time Low 22.6L/100km - 92 Octane gas (Husky/Mohawk)

All Time High 8.12L/100km - 87 Octane gas (Husky/Mohawk)

Last one was from a trip from Calgary, AB to Chilliwack, BC. 835.4km from a really full tank (overflowed, fuel pump's limit trigger was broken) to fill up of 67.8L in Chilliwack.

Trip speeds based on GPS:
Average: 132km/h ...so it says...I "never" exceed the legally posted speed limit ;-)
Max: 231km/h ...so it says...I "never exceed the legally posted speed limit ;-)
Min: 0km/h

 

so if 34.8 mpg was acheived with somewhat aggresive driving (132 avg, 231 hi) then why is it unrealistic to believe that the ~36mpg, that i obtained at a much slower avg speed and no bursts to 231, is possible?

the numbers speak for themselves...

 

The 231km/h was a one time thing. Downhill clear straight and I just wanted to see how fast the car would go. Most of the time the vehicle was traveling steadily between 120 and 140 (depending on hills and such) in manumatic 5th gear so it wouldn't down shift if it got two slow from the cruise speed of 135km/h. I think it's the on-off with the gas that makes the worst gas mileage. If it's steady, you can get some pretty impressive fuel economies out of this engine. Mind you, with the all time low that I had, it was a Amazing Race style game I had with some friends and only made it to about 320km on the tank.