My 2013 G37s coupe has been averaging around 22 mpg for the last 5 or so tanks. I drive it mixed hwy and city aggressive at times.
My wife's 2007 G35 sedan averages above 21 most all the time and on the hwy for trips is around 26-27.

 

Recently purchased 2011 g37xs highest average I've had so far was 20 mpg. Now it dropped down to 18 with city driving.

 

new to me 2011 G37x i have had it about 10 days now , I seem to be getting around 16mpg all city driving with premium fuel. Not the greatest for gas mpg's but still better then my hemi jeep that i traded in getting 9-10mpg on premium fuel

 

2012 G37x, I've owned it for about a year and I average around 20 MPG in the city. During the non-winter seasons, I have a pretty heavy foot too.

 

I seem to be right around 22... a fair mix of city/hwy driving and I almost always punch it off the line.

 

4 years later, still 15 mpg with 70% city

 

Been trying to max out mpg lately. I can get a tank to avg 27mpg on 87 octane with 20% city/80% hwy. On the highway I put it in manual and lock it in 7th. On premium I got one tank to avg 29mpg. I noticed that with the adaptive shift logic sporty driving will cause the trans to stay in 6th even up to 70mph when in full auto. These figures are with the cruise pegged at 74 and gentle driving in the city. With normal driving and periodic hammering I have averaged 24 mpg over 2000 miles on 87 octane during the summer. Obviously pretty happy with this.

 

That appears normal to me.
You are one of the few besides me that admit to using 87 octane and get very good highway mileage.



Telcoman

 

I only use 87 octane and my fuel eco history looks very similar to yours. I don't believe I've ever gotten 29 or higher mpg, but close a couple of times. I've been meaning to put 91 octane in a couple tanks full just to see if there would be much of a difference, but with the gas prices right now, it will wait.

 

I did a one month test of 91 octane and a one month test of 93 octane years ago with my 06 G35 6sp.
I got better mileage using 87 octane and have used it ever since. Put almost 172k miles on the 06 and have 41k on my current 2012 G37S
I use regular 87 octane all the time. Mostly WaWa near my house in New Jersey



Telcoman

 

Haven't posted in a while.

Have owned my 2009 G37 Journey w/18" wheels (auto) since new (12/09). MPGs are great for me. Trip computer slightly over estimates mileage. I'm getting 23 city, 28 hwy, 24.5 average (calculated). Always use premium gas. Generally keep my tires slightly over inflated (35 psi). Probably best car I've ever owned. No issues through 33K miles (low miles, huh?). Getting ready to replace OEM (Dunlop's) tires.

I owned a 2009 Acura TL SH-AWD for a couple years (bought used) and didn't like the ride. The G37 has it all over it in terms of compliant ride. G37 is faster, handling slightly less than TL SH-AWD. Really about the only thing I liked better in the TL was the awesome stereo. MPGs about the same on the Hwy, TL lower around town.

 

averaged 29 mpg at 90 mph from San Antonio to Houston and back. 450+ miles on the trip and still 1/4 tank.

 

Very last tank was 27.9 MPG with cruise and A/C on all the way, plus several significant hills, over a 400 mile round trip interspersed with a bit of city driving. 75 MPH on the hwy.

G37X, 2013, app. 4,000 miles on the clock.

 

150 Miles and 23.3 so far in mixed driving.

 

I've had my 2011 G37x for about a month. The car came with a MPG of 20.2, I reset it almost 2 tanks ago and I'm getting 19.0MPG, with city driving at 70% But I suspect someone at the dealership was racing around in it, as I dropped it off with 19.5MPG on 1.5 tanks, and I picked it up later that day, with some miles on the car, and 19.0 MPG. They claimed it was probably due to the car being left running in idle, but couldn't explain the mileage. They claimed their employees aren't allowed to take cars off the property, unless for a specific purpose. Yet I brought it in for an Emissions check, and they don't perform emissions, and yet when I got emissions done afterwards the car failed the gas cap test. So I still suspect some Shenanigans have occurred!
Because I'm trying to be vigilant about not being heavy on the Go pedal! Like I do on my Trailblazer.