In 1990, Japanese automaker Honda introduced the B21A1 engine to the North American market for the Si trim of its sports coupe, the Prelude. It had a double overhead camshaft valve train layout, and it was the biggest engine yet for the Honda Prelude. The engine carried on into the 1991 model year.
Engine, Transmission and Fuel Economy
The B21A1 engine of the 1991 Honda Prelude Si had a 2.1-liter capacity. This surpassed its aptly named 2.0 Si counterpart, which served as the base Prelude trim with its 2-liter engine. The B21A1 engine-equipped Si vehicles generated 140 horses and 133 foot lbs. of torque, and were paired with a standard five-speed manual transmission (a four-speed automatic was optional). Fuel economy was 22 mpg for city driving and 26 mpg for highway driving, with the 2.0 Si doing slightly better at 23/27 mpg.
Interior and Exterior
Although safety features such as airbags were missing from the 1991 Prelude Si B21A1, it had power windows. Other standard interior features included air- conditioning, cruise control, a stereo system with cassette player and sunroof. A two-door vehicle with standard seating for up to four people, the '91 Prelude Si B21A1 rode on 14-inch alloy wheels.
Si vs. 4WS
The 4WS version of the 1991 Honda Prelude had the same engine as the Si. It was named, however, after the four-wheel steering system that it possessed, a feature that was missing from the Si. Honda also added power door locks to the trim.
Car editors recommend the B21A1-equipped 1991 Prelude Sis mainly because of their superior engine output in comparison with the base 2.0 Si model. Some reviewers, however, have pointed out that the Si suffers from severe understeer, assigning the blame to its two-wheel steering system. The 4WS version of the B21A1 is generally recommended over the Sis.
The original manufacturer's suggested retail price for the 1991 Honda Prelude Si B21A1 was $17,445. As of May 2010, Kelley Blue Book estimates the value range of the car from $3,100 to $3,500. By comparison, the 2.0 Si was about $2,000 less when it first came out, but as of May 2010, has roughly the same value as the B21A1 engine-equipped Preludes.
Honda Prelude Torque Specifications
The Honda Prelude is a two-door coupe that was released between the 1978 and 2001 model years. The final Prelude model came...