[Z06] Rear Diff Gearing
Thread Starter
Race Director
Joined: Jan 2002
Posts: 12,264
Likes: 88
From: O'Fallon Missouri
Rear Diff Gearing
A friend of mine recently purchased a 2003 Z06. We were cruising down the highway last night going 70 mph and I noticed the tach was reading 1900 rpms. Is this normal for a stock geared Z? My ZF6 C4 with 4.10's is turning the same 1900 rpms at 70.
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
On a stock Z06 ... in 6th gear with stock wheels and tires you should see ....
60 MPH = 1500 RPM
80 MPH = 2000 RPM
Basically in 6th gear each 500 RPM is equal to roughly 20 MPH.
So at 70 MPH he should see about 1750 RPM.
Several things could affect his RPM/MPH ratio ... differential changes, gearbox changes, wheel/tire changes.
60 MPH = 1500 RPM
80 MPH = 2000 RPM
Basically in 6th gear each 500 RPM is equal to roughly 20 MPH.
So at 70 MPH he should see about 1750 RPM.
Several things could affect his RPM/MPH ratio ... differential changes, gearbox changes, wheel/tire changes.
