This may sound bold; however, I consider myself an expert on the 1994 Buick LeSabre, please let me explain.
I purchased my 1994 LeSabre Custom, BRAND NEW, back in October, 1994. I live in a suburb of Chicago and this is where my LeSabre has resided, it's entire life. The car has always been adult driven, never abused and kept in the garage for the first 10 years of its life. It is September of 2015 and the car currently has 160,000 miles.
Engine: The 3.8L (or 3800) is arguably the best engine that G.M. has every produced. As far as my Buick is concerned, the engine was trouble free up to 126,000 miles until it developed a few issues. These included, several things failing at approximately the same time including: Crack Position Sensor failing, brake lines rusting away, alternator malfunction and lower intake manifold gasket failure. Being a pretty good backyard mechanic, I was able to repair all of these by myself.
Transmission: Absolutely trouble free. However, I did have the transmission fluid changed every 25k miles.
Interior: My car's seats are still in excellent condition. The center console's lock broke and the hinge failed. I did not fix this. The headliner's glue failed and it sagged badly. To fix this I purchased a replacement headliner on eBay for $40 and two cans of spray adhesive for $20. The headliner looks brand new again. The carpeting is still in fairly good condition with me cleaning it regularly.
Body: This is the where the problems exist. The rocker panels rusted out. I purchased new rocker panels on eBay for $25/ea., removed the old, rusted one and welded on the new ones. They once again look like new. The subframe is prone to failure. I base this comment on much research on the internet. My car was Ziebarted and I believe this saved my car's subframe. However, my subframe bolts were still impacted with them rusting and one snapping off in the unibody. Bis PITA to get it out! After I did get the broken bolt out, I replaced all of the bushings and bolts.
Suspension: I recently replaced the front tie rods, the rear toe links, the front and rear ball joints, the front sway bar links and the bellows boots (which protect the inner tie rods and steering rack).
Finally, despite this car having a few issues over the years, I still think this is one of the best cars I have ever owned. I recently gave it to my son, who drove it to college, where it is now.
Just to let you know that my 1994 Buick limited 3.8 Liter has always got around 30-34 MPG since I owed her. She has over 190,000 miles on her now and going strong. Somebody is blowing smoke telling you that you only get 20 MPG.
I bought this car for one thousand dollars I've had it of nine months no problem at all I gotta say one of the best cars I've ever driven I wish I would of knew how good this car was before I bought my Ford in 2005 I never would of bought it. Driving my Buick is like driving on clouds.
I bought this car recently with only 78000 miles expecting a reliable car. It could just be a lemon, but there have been a ton of electrical issues. Performance-wise, the car is very disappointing. Many people would find the ride comfortable over bumps, but in reality, it has very poorly tuned suspension. There is hardly any damping so the car bounces far too much after hitting a bump. This coupled with very soft springs is a bad combination. When turning quickly, the body roll is very substantial. So much so that it could be a safety concern. In a situation where you had to swerve, the body develops so much inertia that loosing control could easily happen. Acceleration is surprising
Re-tune suspension by stiffening anti- roll bars, springs, and increase damping in shocks. Loose some weight. Increase steering feel (very numb as it is).