Hard time getting more MPG - 98' Sunfire

[CanadianSunfire]

Hello everybody. I've been interested in the whole "eco thing" for some time, and have been squeezing every penny I can out of a tank of fuel for my 98 Pontiac Sunfire (2.2L Auto 4 spd).

I've been reading this forum for the past two weeks, and finally became a member the other day. The knowledge on this forum is amazing!

Living here in Eastern Canada we are right in the middle of a cold winter, and my gas mileage is sure letting me know!

The car has quite a few kms on it. 280,000 to be exact, but i've replaced just about every sensor, and filter on the thing since i've owned it (3 years). It's been a great car and runs well!

I've always believed in using synthetic products, and in turn my sunfire has had synthetic 5w30 in it for the three years. Current oil is Royal Purple.
What is everyone's view on Royal Purple? Previously I had been using Lucas 5w30.

In the past two weeks i've done a few things:
Cut a 3 inch hole in the air box and ran a 3 inch flex dryer hose to the exhaust manifold, removed my long antenna and replaced it with a smaller flexible rubber antenna. I have removed the licence plate that was mounted directly in the middle of my "v" shaped nose cone (figured this might have some wind resistance).

The tires on the car are winter studded at the moment and are at 32psi. The sidewall says "MAX 35 PSI". Should i inflate these more?

I've been doing a lot of coasting in Neutral when I can (ie coming to a stop sign, red light, or going down hill).

So far I haven't noticed much of a difference in fuel mileage. Six days ago I put 36 Liters of fuel in the car, and i've gone only about 280kms. So for roughly 3/4 of a tank i've only gone roughly 300kms.

EPA Average for this car is 23 city 25 hwy.

I'd like to get more out of it!

I've ordered a vacuum gauge to install on the dash, and i plan on doing a front end block-out with a front belly pan in the near future.

I know a scangauge would be a good option, but i'm a bit low on extra funds for one at the moment.


Any added tips would be appreciated!

Thanks!