Ford Mustang (fourth generation)
Engine output summary

Year
Base Model
GT
Cobra
Special Edition
1994
145 hp (108 kW) @ 4000 rpm 215 ft·lbf (291 N·m) of torque @ 2500 rpm
215 hp (160 kW) @ 4200 rpm 285 ft·lbf (386 N·m) of torque @ 3400 rpm
240 hp (179 kW) @ 4800 rpm
-
1995
145 hp (108 kW) @ 4000 rpm 215 ft·lbf (291 N·m) of torque @ 2500 rpm
215 hp (160 kW) @ 4200 rpm 285 ft·lbf (386 N·m) of torque @ 3500 rpm
240 hp (179 kW)
300 hp (Cobra R)
1996
150 hp (108 kW) @ 4000 rpm 215 ft·lbf (291 N·m) of torque @ 2500 rpm
215 hp (160 kW) @ 4400 rpm 285 ft·lbf (386 N·m) of torque @ 3500 rpm
305 hp (227 kW) @ 5800 rpm 300 ft·lbf (406 N·m) of torque @ 4800 rpm
-
1997
150 hp (108 kW) @ 4000 rpm 215 ft·lbf (291 N·m) of torque @ 2500 rpm
215 hp (160 kW) @ 4400 rpm 285 ft·lbf (386 N·m) of torque @ 3500 rpm
305 hp (227 kW) @ 5800 rpm 300 ft·lbf (406 N·m) of torque @ 4800 rpm
-
1998
150 hp (108 kW) @ 4000 rpm 215 ft·lbf (291 N·m) of torque @ 2500 rpm
225 hp (168 kW) @ 4750 rpm 290 ft·lbf (393 N·m) of torque @ 3500 rpm
305 hp (227 kW) @ 5800 rpm 300 ft·lbf (406 N·m) of torque @ 4800 rpm
-
1999
190 hp (142 kW) @ 5250 rpm 220 ft·lbf (298 N·m) of torque @ 2750 rpm
260 hp (194 kW) @ 5250 rpm 302 ft·lbf (409 N·m) of torque @ 4000 rpm
320 hp (239 kW) @ 6000 rpm 317 ft·lbf (429 N·m) of torque @ 4750 rpm
-
2000
190 hp (142 kW) @ 5250 rpm 220 ft·lbf (298 N·m) of torque @ 2750 rpm
260 hp (194 kW) @ 5250 rpm 302 ft·lbf (409 N·m) of torque @ 4000 rpm
-
385 hp (Cobra R)
2001
193 hp (144 kW) @ 5500 rpm 225 ft·lbf (305 N·m) of torque @ 2800 rpm
260 hp (194 kW) @ 5250 rpm 302 ft·lbf (409 N·m) of torque @ 4000 rpm
320 hp (239 kW) @ 6000 rpm 317 ft·lbf (429 N·m) of torque @ 4750 rpm
265 hp (198 kW) (Bullitt)
2002
193 hp (144 kW) @ 5500 rpm 225 ft·lbf (305 N·m) of torque @ 2800 rpm
260 hp (194 kW) @ 5250 rpm 302 ft·lbf (409 N·m) of torque @ 4000 rpm
-
-
2003
193 hp (144 kW) @ 5500 rpm 225 ft·lbf (305 N·m) of torque @ 2800 rpm
260 hp (194 kW) @ 5250 rpm 302 ft·lbf (409 N·m) of torque @ 4000 rpm
390 hp (291 kW) † 390 ft·lbf (529 N·m) of torque
305 hp (227 kW) (Mach I)
2004
193 hp (144 kW) @ 5500 rpm 225 ft·lbf (305 N·m) of torque @ 2800 rpm
260 hp (194 kW) @ 5250 rpm 302 ft·lbf (409 N·m) of torque @ 4000 rpm
390 hp (291 kW) † 390 ft·lbf (529 N·m) of torque
305 hp (227 kW) (Mach I)

Question: Which engine models improved performance from 1997 to 1998?
Answer: From 1997 to 1998, the GT model engine improved from 215 to 225 hp.