i bought my used '03 350z from my local nissan dealership a few months ago, but i noticed that my city gas mileage is sooo bad. it would range from 10-16 mpg. however, my highway mileage is great 27-29 mpg. i don't get it. . is there anything i should check or any diy i could do to improve my mileage? i have no idea how well the previous owner took care of the car too . any help would be appreciated

 

Hey ya, sounds pretty normal to me. Consider around town you are doing a lot more gear changes, ah la, using more gas. Open road, not many gear changes.
Round town for my Z normally about 430kms ish, open road between 700-800kms depending on the terrain etc.

Don't forget you are driving a reasonably powerful car, and a physically fairly heavy car.

 

Check you milage computer. What is the average speed you have in each of your situations. In the city you aren't getting into your most economical gear(6th or high) and you are braking a lot which is subtracting momentum that you spent gas for.

 

hmm well, on the freeway my average speed i would say around 65 mph and in the city i guess its around 15. it might also be the fact that i live in san francisco and theres a lot of inclines here. well thanks for the help guys

 

Welcome to the 3.5 liter Nissan engine. This is completely normal.

 

sounds like your foot is a little heavy to me. I run 19.9avg in city and 34mpg on the highway. '03 base with several mods. My mods did improve my city mileage by a mile per gallon or so. 10-16 is way low, start shifting before 4k RPM's and it will solve your problem.

 

i usually shift between 2k-3k rpm's and rarely push my car, maybe i need to do some cleaning to the fuel injectors?

 

Dunno about that. My 07 NISMO has been consistently getting 22MPG (over the tank, I don't mess with that whacky computer or trust it) and I shift more or less the same at about 3K or less, unless I feel like doing something fun. I'm kinda curious, but not obsessed with where my 27MPG is.

 

i have an 06 with 6,200 miles and i get about that

 

I admit, I'm rather spontaneous when it comes to how fast I go. For a moment, I'll be going slow, and then suddenly feel a burst of adrenaline and decide to bring it up to 70 or 80, then chill out and go slow again. But, my mileage computer is wacked. It says my average speed is 17 mph and my gas mileage is usually around 12, 13 or 14. I try to reset it, then drive on it for a while but it doesn't change. Maybe it's because I've got only a grand on the odo?

 

you just answered your own question.