Many of us plan on buying a Challenger SRT (either 6.1 or 6.4) because we want the baddest one available. We all know that for about $7,000 more, and SRT comes with 425 hp, upgraded interior, handling package, Brembo brakes, and "elite" status, etc. But how much faster is it than an RT with the Road and Track option (350 hp)?
For everyday driving, there is not a huge difference. However, when you get on it, the SRT smokes the RT, especially after 70 mph. See the following chart from Car and Driver:
R/T with RT package
ACCELERATION:
0 to 30 mph: 2.2
40 mph: 3.1
50 mph: 4.3
60 mph: 5.6
70 mph: 7.1
80 mph: 9.2
90 mph: 11.4
100 mph: 13.9
110 mph: 16.7
120 mph: 20.8
130 mph: 26.0
140 mph: 32.6
Street start, 5-60 mph: 5.8
Top-gear acceleration, 30-50 mph: 2.8
50-70 mph: 3.5
Standing 1/4-mile: 14.2 sec @ 101 mph
Top speed (governor limited): 145 mph
BRAKING
70-0 mph @ impending lockup: 169 ft
HANDLING
Roadholding, 300-ft-dia skidpad: 0.78 g
Understeer: minimal moderate excessive
FUEL ECONOMY
EPA city driving: 17 mpg
EPA highway driving: 25 mpg
C/D-observed: 19 mpg
INTERIOR SOUND LEVEL
Idle: 45 dBA
Full-throttle acceleration: 78 dBA
70-mph cruising: 66 dBA
SRT8
ACCELERATION:
0 to 30 mph: 1.9
40 mph: 2.7
50 mph: 3.6
60 mph: 4.7
70 mph: 5.9

80 mph: 7.4
90 mph: 9.2
100 mph: 11.2
110 mph: 13.3
120 mph: 15.9
130 mph: 20.0
140 mph: 24.7
150 mph: 30.7
Street start, 5-60 mph: 4.9
Top-gear acceleration, 30-50 mph: 2.7
50-70 mph: 3.0
Standing 1/4-mile: 13.2 sec @ 109 mph
Top speed (redline limited): 173 mph
BRAKING
70-0 mph @ impending lockup: 162 ft
HANDLING
Roadholding, 300-ft-dia skidpad: 0.89 g
Understeer: minimal moderate excessive
FUEL ECONOMY
EPA city driving: 14 mpg
EPA highway driving: 19 mpg
C/D-observed: 14 mpg
INTERIOR SOUND LEVEL
Idle: 50 dBA
Full-throttle acceleration: 76 dBA
70-mph cruising: 69 dBA