G35 gas mileage issue

[engineer1]

Hello, I'm new. Purchased my 2007 G35S used last May w/about 51k. I like the car but am troubled by low gas mileage. On a recent road trip I did less than 18 mpg. Around town it's in the 14-15 mpg range. It just seems that highway mileage ought to be much better. Is there anything I should have checked? Any advice/comments would be appreciated.

[biggie]

Air Filter, premium gas, fuel filters.

I get 20mpg average city and hwy, can get 22-24 if all highway.

[engineer1]

I do use premium (no ethanol, no less!) and have had a BG fuel system treatment. Haven't checked any filters, though. Seems that the engine runs pretty high rpms at speed (3,000+) - is this normal? Thanks

[biggie]

At Highway speeds (70+) 3krpms is normal.

[telcoman]

Hello, I'm new. Purchased my 2007 G35S used last May w/about 51k. I like the car but am troubled by low gas mileage. On a recent road trip I did less than 18 mpg. Around town it's in the 14-15 mpg range. It just seems that highway mileage ought to be much better. Is there anything I should have checked? Any advice/comments would be appreciated.

Check tire pressure.

Try regular

Telcoman

[kmckis1029]

wow 18mpg is low for highway... thats what i got combined highway/city on my old 2005 g35x... i stayed between 18-22 combined mpg.

+1

check air filters, fuel filters, run prem gas, check tire pressure, and maybe even see about induction cleaning and reset your ECU after all of that is done. Also is your car always over loaded? like do you ride with a full trunk?

but if you just suffering from a heavy foot, we can't help you there lol