I'm a 2003 5mt owner, but I noticed a drop in mpg from 39.88 to 35.5 on my last tank of gas, when I used the AC almost continuously.

I've begun to think of the AC button as my "Turbo Booster." Whenever I have to merge onto I95 I punch it off, and then downshift to fourth gear....

 

i'm averaging 30 mpg in all city driving with my coupe 5-speed manual, and I drive like a maniac.

my advice to anyone with a new car is to break it in like the manufacturer suggests.

 

yeah. i just filled for 2nd time, 25 dollars 9.2 gallons. 330 miles. first fill up was 8 gallons at 270 miles. It pays to break it in properly. don't floor it off the lot.

 

my first few tanks were the same way, now im avg 34 in town. i also have done some long hw driving and i pulled 42mpg. i pulled 547 out of that tank before i filled. but id say i avg about 450-500miles on a full tank of gas

 

What does "break it in" means?

 

breaking in a car. a new car is like a virgin, you cant just jump in it and beat it. you gotta take it slow. not redlineing your car. its a 600 to 1000 miles of actually being nice to your car. i made sure i never went over 5 grand, and i tryed not to accelerate hard at all during this period of time. inside the engine small metal fragments break off, and when they melt they form to the side wall. when you do you first oil change, stick your hand in the oil, you'll find the small metal shavings. break in is very important

 

I'm up to 35 MPH now, 90% highway driving. 120 miles a day commute. AD on. 75 MPH average. My first couple of tanks, like others mentioned, were lower mileage. I'm happy with it now at 35. If I drop my speed down to 60-65, I'm sure there's a few more MPG there.

S.C.

 

I'm getting around 27 mpg in my '06 Si. When I originally bought it, gas mileage was one of my needs, but after driving this car I care much MUCH less. IT IS TOO FUN TO DRIVE. YAYYYYYY!!!!!!