The 1991 BMW 318i convertible delivers a smooth 1.8-liter four-cylinder engine that revs willingly to redline, but chassis rigidity suffers compared to the hardtop 318is. Car and Driver's test car accelerated to 60 mph in 9.7 seconds and completed the quarter-mile in 17.2 seconds at 81 mph, roughly matching a Honda Accord's pace.
The convertible weighs 2,910 pounds, more than 250 pounds heavier than the 318is sedan due to additional bracing and reinforced doorsills. It costs $29,060, nearly $7,000 more than the sedan. The five-speed manual transmission pairs with the 134-horsepower engine, delivering uninterrupted power from stop to top speed.
The problem emerges in corners. Where the hardtop feels tight and crisp, the convertible wiggles and twists. The rear end sends waves of jiggles forward on demanding pavement, undermining BMW's refinement reputation. This behavior surprises the testers, since BMW's Wackersdorf plant builds convertibles as dedicated convertibles rather than sedans with removed roofs, an approach that typically improves chassis stiffness.
Wind noise runs acceptably low with the top down. The standard six-speaker stereo rates among the best. With the top up, normal conversation echoes through the cabin.
The manual soft-top requires standing outside the car to raise or lower it. Dropping the top is easy, and when folded it sits under a hard cover. Raising the top demands patience unless appearance drives the purchase. The top fabric color-matches the paint and draws attention.
The 325i six-cylinder convertible with power-top costs about $7,500 more. BMW plans to sell twice as many of the six-cylinder versions as the four-cylinder 318i.