33.1 so far!
 

Just bought a 29K mile 1999 Buick Park Avenue. Took a 188 mile (94 each way) almost pure hiway trip last weekend. Pumped tires to max, folded in my mirrors, used SGII, and coasted using pulse and glide. Filled up the tank before I left and at end of trip. Total for the trup using pencil was 33.1 mpg.
Pretty happy with that. So far around town, using the SGII, I have been able to get the tank average to around 23.5 mpg for the tank. The 3.8 Series II motor is pretty good at mileage for a v6.

Will be adding a Traverse lower air dam, a grill block and eventually rear fender skirts. Goal is 37 mpg for hiway. May try to smooth out some stuff underneath. Can't decide if I should get Impala police 16inch steel wheels so I can add smooth wheel covers or just live with the Buick alloys.

Any other Buick modders out here?

Great job. Set up a mileage log in the garage. Looking forward to seeing you hit your 37 mpg highway.

3.8 Pontiac.

I also have the drop in K&N, there seems to be no way to do a cold air without cutting stuff.

I run completely stock under the hood. If you haven't take a look at the information on K&N vs stock, do a site search.

Like this one
http://ecomodder.com/forum/showthrea...ers-11418.html

Also much information on CAI and WAI.

Best improvements for me
"Nut behind the wheel" (driving habits) see 100+ Hypermiling Tips
Limit AC use
Tire pressure