Hi everybody I just ran across this website. And I sure am glad I did. I currently drive a 99 sl1 that I bought last year with a bad motor. Replaced that and have been pretty happy so far with my best mpg being 38.7 after a fresh oil change in the summer months. In the winter its drops all they way down to 29 (minnesota fuel). Any tips for me on how to up the mpg maybe just a titch more. Not sure hoiw much I'll do to this car Since I'm looking to replace this one with another sl1. I ran across a guy who did a total underbody pan and that was neat. So now I'm kinda thinking what mods can I do to atleast break 40. Lemmie know I appreciate it
The most important mod is your driving; whatever you're doing, you may be able to do it better, and there may be other techniques that you could use too. There's plenty of techniques discussed on this site.
For modifications to the car, start with tire pressure. Increase it, no higher than the maximum marked on the tire, also not high enough to adversely effect ride, handling, or wear. I usually hit the maximum marked on the tire before my ride is unpleasant, handling is worse, or wear is uneven.
A lot of people with early Saturns have success with a warm air intake. Search the site for saturn WAI or HAI (some people call it hot air intake). I don't know if it would work on your '99.
Make sure to put the proper fluids in your Saturn for instance make sure you only use Prestone DEX-COOL 50/50
for your spark plugs DO NOT use anything but the stock NGK nickel plugs otherwise you will probably create misfires
try changing the stock thermostat for a stant 195
try some Seafoam in the oil and in the gas tank
take off the throttlebody and use some choke cleaner, a tooth brush, and a rug to clean the plate and spray some in the manifold to clean it out as well