http://www.caranddriver.com/reviews/2015-ford-mustang-gt-instrumented-test-review
DIMENSIONS:
Wheelbase: 107.1 in
Length: 188.3 in
Width: 75.4 in Height: 54.4 in
Curb weight: 3810 lb
C/D TEST RESULTS:
Zero to 60 mph: 4.5 sec
Zero to 100 mph: 10.4 sec
Zero to 130 mph: 17.8 sec
Rolling start, 5-60 mph: 4.9 sec
Top gear, 30-50 mph: 9.6 sec
Top gear, 50-70 mph: 9.0 sec
Standing ¼-mile: 13.0 sec @ 113 mph
Top speed (governor limited): 164 mph
Braking, 70-0 mph: 149 ft
Roadholding, 300-ft-dia skidpad: 0.95 g
FUEL ECONOMY:
EPA city/highway: 15/25 mpg
C/D observed: 17 mpg
http://www.caranddriver.com/reviews/2013-ford-mustang-gt-long-term-test-wrap-up-review
DIMENSIONS:
Wheelbase: 107.1 in
Length: 188.5 in
Width: 73.9 in Height: 55.8 in
Curb weight: 3650 lb
PERFORMANCE: NEW
Zero to 60 mph: 4.5 sec
Zero to 100 mph: 10.6 sec
Zero to 130 mph: 18.8 sec
Rolling start, 5-60 mph: 4.8 sec
Top gear, 30-50 mph: 10.1 sec
Top gear, 50-70 mph: 8.8 sec
Standing ¼-mile: 13.0 sec @ 111 mph
Top speed (governor limited): 147 mph
Braking, 70-0 mph: 169 ft
Roadholding, 300-ft-dia skidpad: 0.89 g
FUEL ECONOMY:
EPA city/highway driving: 15/26 mpg
C/D observed: 19 mpg
Cars are essentially identical performance wise... but the current GT seems to have better brakes.