• The Honda Civic was originally introduced by Honda in 1972 as a small, two-door hatchback. The 1991 Honda Civic came in three variants: hatchback, sedan and the sportier CRX. The Si trim option featured a bigger engine and sportier look. That designation was only available on the hatchback and CRX, though the EX sedan had the same engine.
  
  

Engine and Transmission

• The 1991 Honda Civic Si featured a naturally aspirated, inline four-cylinder engine with a rating of 108 horsepower. The engine had a displacement of 1.6 liters and was capable of 100 foot-pounds of torque. It was coupled with a five-speed manual transmission. This was the only available engine for the Si trim, and it was meant to operate on gas/fuel with a PON/RON rated at an 86/91 octane level. That means that this engine will accept regular, unleaded gas.
  
  

Interior and Exterior

• Both the Hatchback and the CRX Civic had only two doors, but the Hatchback was capable of seating up to five individuals while the CRX was limited to two. The front headroom and legroom of the Hatchback was measured at 38.2 and 43.3 inches, while the CRX was measured at 36.7 and 40.8 inches, respectively. The rear headroom and legroom for the Hatchback measured 36.6 and 30.4 inches. The curb weight of the Hatchback was 2,291 pounds while the CRX came in lighter at 2,174. The Hatchback was the bigger car of the two, with length, width and height measurements of 157.1, 66.3 and 52.5 inches, respectively. In contrast, the dimensions of the CRX were listed at 148.5, 65.9 and 50.1 inches. There was also a marked difference in the wheelbase and turning diameter measurements, as the Hatchback measured 98.4 inches for the wheelbase and 32.4 feet for the turning diameter, compared to 90.6 inches and 30.4 feet for the CRX.
  
  

Steering and Suspension

• Beside the engine and transmission, both the Civic Hatchback and CRX had a similar steering, suspension and drive train setup. Both types came with rack-and-pinion steering and also featured front and back independent spring coil suspensions. Both units were front-wheel-drive vehicles.
  
  

Fuel Economy

• The inline four-cylinder engine in both vehicles had a fuel efficiency rating of 28 miles per gallon for city driving and 32-33 miles per gallon for highway driving. The maximum capacity for the fuel tank of both units was 11.9 gallons.