^aTier 2 default standards were Tier 2 emission levels in the Clean Air Act for consideration by EPA. Since the announcement of Tier 2 standards, these are no longer relevant.

^bA 10-kw electric motor/generator attached to the engine supplied by the battery adds to the propulsive power during maximum acc eleration.

^cGM has added a rear electric motor from Unique Mobility that contributes to kW of peak propulsion power and 150 Nm (110 ft-lbs) of torque.

^dFord has committed to production of an HEV with a $3,000 cost premium (assumed to use gasoline).

Acronyms: CVT = continuously variable transmission; DIATA = direct-injection, aluminum-block, through-bolt assembly; DOHC = dual overhead cam; EMAT = electro-mechanical automatic transmission; FMVSS = federal motor vehicle safety standards; LIMBT = light weight injection molded body technology; MTX = manual transaxle; SULEV = super ultra low emission vehicle; ULEV = ultra low emission vehicle; VNT = variable nozzle turbo; VTEC = variable valve timing and lift electronic control.

Source: Adapted from USCAR.