Mine varies, I do a lot of city driving (suburbs), not too slow but not too fast, most of the time my avg MPH is about 25mph-30mph. Im about 80%-85% city and 15%-20% highway.

Warmer months, my miles per tank is at or between 300-350 (19 mpg - 22 mpg) (based on without Mods: stillen gen3 cai and stillen catback exhuast - #'s should remain same or improve by a small amount overtime)

Colder months, my miles per tank is at or between 275-330 (17 mpg - 20 mpg) (based on with Mods: stillen gen3 cai and stillen catback exhuast) - #'s should remain same or improve by a small amount overtime)

Usually my trips on the highway vary and aren't long but i've seen avg mpg #'s while driving on hwy near 27 mpg - 30 mpg.

I run 93 octane always.
Mods: stillen gen3 cai and stillen catback exhuast (completed this feb and march of 2017)

 

I have an 09 G37x sedan and I average 21mpg. I do about 50/50 city/highway and I only have Tanabe Medalion Axleback as upgrades. I run Premium (which is 92 octane where I get it)

 

Totally stock 2013 G37x sedan, 40k miles. I get just under 19 MPG, I do 100% city driving here in Chicago. I don't blast it from stop lights all that much - but once in a while....

Here's an interesting thing I found: My last car was a 1994 Toyota Celica GT. -I tend to keep cars a LONG time- I got the G37x in October 2016.

My Celica got ~17 MPG in town. The G37x gets 2 MPG **BETTER** mileage than the Celica, even though the G has 2.4 times the horsepower and weighs 1,200 lbs more. And here's an even more interesting fact: adjusted for inflation, the 2013 G37x cost me $4,000 LESS than I paid for the 1994 Celica when I bought it in 1999- despite the fact that the G37 had 20,000 FEWER miles on it and came with the CPO warranty and has the Premium package and navigation.

Now, hands down the G37 is BY FAR the better car- so it amazes me what a VALUE it was! I attribute this to the fact that there are a ton of off-lease G37 sedans out there, and Infiniti just doesn't have the brand cachet (and higher used-car prices!) that some brands have.

Will my 2013 G37 be as reliable as my Celica was? I suspect it may well be; Consumer Reports shows the 2013 G37 to have very few problem areas. Plus, I have a lot of preventive maintenance done - like have the G37 transmission fluid replaced every ~40,000 miles along with transfer-case and differential lubricants, have the brake fluid and coolant changed often, use synthetic oil, and so on. G37's are a pretty reliable car, and 2013 seems the most reliable vintage.

 

My norm is about 21mpg. But recently, I have been trying to see what my car would read on a certain stretch of flat, windy roads near my house. Highest I got was.....Drum roll please....50.3! I drove between 30 and 40 miles per hour and seriously controlled the acceleration/throttle. Now if only that number would hold true on my 70 mile highway commute, I'd be better than most hybrids

 

Just got back from a trip to Indiana. My first tank going "uphill" (Texas coastal plain to Little Rock, Ar) netted me 30 mpg. That's with half the leg at 78 MPH and the rest at 73 MPH.

Last tank on the return trip going downhill was only 24 mpg. <Shrug> Average for the 2,250 mile trip was 26 MPG, give-or-take a few tenths. My lifetime average went from 20.7 to 20.9 mpg, though it will return to "normal" in just a few weeks.

 

i have a bone stick 2015 Q40 AWD, with 25k on the ticket. I'm abgeraging 25 mixed driving; pretty easy on the throttle most off the time. I did get 36 at 55 in NM on 2 lane highway w a tail wind. Out west I get 2 mpg better than south east (recently moved from Nashville to Boise). Guess the higher elevation and dryer air make a difference even though there isn't any 93 RON gas out west. Best I can find out here is 91,

 

Your octane requirement drops as you increase altitude.

 

Ah...good to finally know that! Thanks!

 

Jealous of all of you getting 20+ mpg. I'm currently at 17.2 mpg estimated. A lot of city driving though so that has a lot to do with it.

 

Don't feel too bad. My 1994 Toyota Celica 2.2 L / 135 bhp (WOW!) got around 15 MPG in town.... not HALF the car my G37 is.

 

85% Highway at 70-78 MPH I get around 23 MPGs. Can't trust the computer on the dash because that's not "rolling miles" and it includes idle time (Just FYI).

Really wish Infiniti would have extended the top gear out because I'm burning premium at 2500 RPMs at 75 MPH......... Seems a bit high.

 

I get ~20 MPG, 50/50 city highway. Bone stock G37S sedan, 7AT, driven a bit crazy.

Something to keep in mind is MPG changes with the weather. Best time is probably the fall, after A/C load is very high but before they switch to winter blends.

 

66 Miles after refueling, cruise set at 62 mph. It peaked at 29.4 when I got off the highway. Pic below taken after 7 miles of city driving when I got home.

 

Why cover your odometer? Just curious.

 

Yea that's really odd. Why is it a secret?