Anyone have the gear vs speed chart for the 2021 (392 Scat Pack?) my search FU is terrible. 390 final? Thanks, Fran
Thank you. After looking at the chart, I came up with this; I was looking for the "maximum" speed in each gear (1 through 4) for shifting, up or down. Assuming the TR-6060 in the 2021 392 Scat Pack is Gear Ratio Calculator (tremec.com) 3.9 Final TR-6060 Gearing 1st = 2.97 2nd = 2.10 3rd = 1.46 4th = 1.00 5th = 0.74 6th = .05 R = 2.90 Tire height of 28.4" (305/35-R20) 6000 RPM 1 = 44 2 = 62 3 = 89 4 = 130 6400 RPM 1 = 47 2 = 66 3 = 95 4 = 139
This is true but the only thing that matters is the tire diameter So if you are running the 275/40-R20 the math is about the same. Less than or about 1mph.
My 2021 Scat Pack has 275/40R/20 on the rear. The speedo shows the identical speed as the Garmin Navigation unit.