CALCULATING OVERALL TRANSMISSION RATIOS "i"

WARNING: This page is about a different car, the 2009 Audi TT and 2008 Audi TT. However, it is still accessible from the selected car via links, so may be relevant.

Example:

	6. Gear	Final drive
Drive gear	ZG₁ = 40	ZA₁ = 20
Driven gear	ZG₂ = 33	ZA₂ = 72

i = Z₂ : Z₁ (Z₁ = No. of teeth drive gear, Z₂ = No. of teeth driven gear)

i_G = gear ratio = ZG₂ : ZG₁ = 33 : 40 = 0.825

i_A = axle ratio = ZA₂ : ZA₁ = 72 : 20 = 3.6

i_total = total ratio = i_G x i_A = 0.825 x 3.6 = 2.97