[99LeCouch]

Bumping this. I used to have a 1999 Buick LeSabre, and that car always got insane fuel economy for a large car. One incredible tank it got 39 mpg over 614 miles. That was a long, slow drive up I-95...

With the 2.86 gearing in it, its sweet spot for MPG was right around 55-57 mph. Your SSE with its 3.05 gearing is slightly slower.

That belly pan will help out nicely with mileage since otherwise a LOT of air is hitting the oil pan. Also, the L26 UIM is mainly cosmetic, and doesn't do anything a revised L36 UIM will do.

Enjoy your rolling sofa! I quite enjoyed mine the time I had it.