Both cars churn out 617 horsepower and 553 pound-feet of torque, but the M8 is 0.1 seconds quicker to 60 mph from a standstill, as it can pull off the sprint in three seconds flat, while the M5 needs 3.1 seconds. ... The M8 tips the scales at 4,295 pounds, while the M5 comes in at 4,370 pounds.20 Feb 2020