B13 is the chassis code for a 1991-1994 USDM Nissan Sentra. These cars are a legend in Nissan circles as the second coming of the Datsun PL510. They are so loved that they are called "Classic" Sentras in Nissan circles. If you say you have a Classic, it is understood to be one of these cars. These cars are still made new in Mexico, where they are the number one selling car. In Mexico, it is sold as the "Tsuru". For me, the styling really does it for me as I love the rounded boxiness of these cars. Plus, they have a great handling chassis and an amazing amount of interchange like all Nissans. For example, the brakes on these cars are terrible. But, you can put the AD22VF brakes from a NX2000 on the front, and the rear discs from an SE-R on them along with the master cylinder off a 4 wheel disc U12 Altima pretty easily as long as you have at least a 14 in wheel. I have a set of these brakes that were going to go on my B14 Sentra, but it got wrecked before I could do it.