During its 14-year production life, the Nissan Maxima has survived four evolutions. The last version, which went out of production at the end of the 1994 model year, is perhaps the most familiar. Its distinctive appearance and sporty character - emphasized by an advertising campaign that stressed performance - made it reasonably popular with the general public while attracting the attention of car enthusiasts. No more. Nissan touts the 1995 Maxima as a leader in traditional sedan virtues, such as value, content and style, but downplays the performance image. Driving pleasure has not been ignored, but the focus has shifted in hopes of bringing in mainstream buyers. According to Nissan, early sales returns indicate that this approach is paying off. By that all-important standard, the new Maxima represents a major improvement over past versions and a solid threat to perennial chart-toppers such as the Ford Taurus, Toyota Camry and Honda Accord. By almost any other standard, the newest Maxima is indeed a better car. It offers fresh styling, a roomier interior, improved fuel economy, better straight-line performance and a more comfortable ride than any previous Maxima. But the shift in emphasis from sporty to, well, less sporty may drive owners of older Maximas elsewhere when replacement time rolls around. And it may throw some customers to such niche performance sedans as the impressive Volkswagen Passat GLX. Those are risks Nissan seems willing to take. So far, the company's strategy seems to be the right one.