172R
The Skyhawk R was introduced in 1996 and is powered by a Lycoming IO-360L2A of 160 horsepower. This is the first Cessna Skyhawk to have a fuel-injected engine.
The 172R's maximum takeoff weight is 2,450 lbs (1,113kg). This model year introduced many improvements, including a new interior with soundproofing, an all new multi-level ventilation system, a standard four point intercom, contoured, energy absorbing, 26g front seats with vertical and reclining adjustments and inertia reel harnesses.
[edit] 172SP
The Skyhawk SP was introduced in 1998 and is powered by a Lycoming IO-360L2A producing 180 horsepower. The maximum engine rpm was increased from 2,400 rpm to 2,700 rpm resulting in a 20hp increase over the "R" model. As a result, the maximum takeoff weight was increased to 2,550 lbs (1,157kg).
The 172SP is built primarily for the private owner-operator and is offered with the Garmin G1000 avionics package as standard equipment and leather seats.
As of 2007, Cessna offers both the R and SP models.