So I have come to realize my G has been getting real poor mileage. It's an 09 7at and according to the car info, it's registering at like 13mpg. I'm going to do the 60k service shortly and was planning on swapping plugs in hopes it may help. Any idea what else it could be? Any help would be appreciated. TIA

 

i had a 2010 g37x coupe and I averaged between 12-13mpg. I cleaned the throttle body, changed spark plugs, and couple things I don’t remember anymore. It didn’t make any difference at all. If you search the forum I complained about it a few times. I had the car for several years and it’s been like that from the beginning. Sorry, I’m no help but goodluck.

 

Get a Prius or a Honda

Telcoman

 

I didn’t mind the MPG only IF my G I actually felt like a decent car. My G was so sluggish and very slow off the line that any car could beat it from a stop. It felt like I was driving something very heavy and carrying a ton of weight holding it back.

 

first G i test drove was like that - felt like it only had 200hp, and sluggish. was also a lot rougher than it appeared in pics.

luckily i tried another, and it is worlds apart from the first POS i drove.


OP could try new air filters, spark plugs, clean throttle bodies and MAF's. and run a few bottles of Techron concentrate in the gas tank for starters ...

 

Come on man, quit playing lol

I used to drive V8s so used to not getting good mileage but damn I did expect a bit better from my G. Won't get rid of it though lol she's my baby

 

Stop and go traffic kills mileage. Your location says LA so I assume you sit in a lot of traffic. Not even a Prius would get good mileage in that area.

 

Over the road mileage for my G37S and and my previous 06 G35 6 speed is excellent.

Four fill-ups from NJ to Florida. Two fill-ups for local driving while in Florida, and four fill-ups on the return to NJ



Short trips, sitting in traffic kills MPG

Have you ever filled up your vehicle, drove 350 -400 miles at 70-75 MPH and filled up again and checked your MPG?

I never use cruise control which reduces MPG 1-2 MPG. tires at 35lbs when cold, and remove junk from the trunk.

Telcoman

 

I'm all city/suburb traffic, so i usually average 17-19 mpg.

better than my Evo was, which was 16-18mpg.

 

This is a "GT" class car, highway its where it belongs.

My 2012 X was sluggish also from a stop. Before the tune, it was clocking 215 hp... far less than the "documented" 20% drivetrain loss for the X models. Yet mileage was excellent, about 26 MPG mixed driving.

Now that it is tuned/catback/HFC/Intakes, I can't do any better than 22 MPG, but I can get out of the hole PDQ.

As others have said, city driving/short trips/lots of stop-n-go are no friends to mileage for these cars.

 

13 mpg seems awfully low!! I am in a chicago suburb, mostly city driving (gauge says I usually avg about 23-30 mph)... about 20% highway speeds. I usually get about 17-19 in the cooler months and 18-21 in the warmer months. I am modded to and I drive a mix of spirited and conservative. G37x 7AT. When you are in traffic, try to cruise and not floor it for a short distance etc. Maybe clean the injectors, 02 sensor, filter...

 

Yea it's horrible. I'm about to do the 60k service on it so hopefully it'll register better, thinking of resetting the ecu to see if that helps the car "learn" to be more efficient lol. I get I'm in LA and mpgs suck but damn lol

 

Change trans and diff fluid along with new air filter fuel system clean spark plugs and check air pressure. What people forget when they put on larger wheels and tires and add a stereo set up it all affects mpg

 

Yea will do that this weekend, officially hit 60k today. I was thinking of replacing the spark plugs although I heard they're rated for 100k

 

Spark plus didn’t do anything for me. I changed mine around 40,000 miles thinking the same thing.