The Volvo C30 Efficiency is a version of the 1.6D rated at 105 horsepower with reduced chassis height, a new rear roof spoiler, a new rear bumper, underbody panels, optimised engine cooling, aerodynamically optimised 16-inch wheel rims, low friction tyres, revised gearing on third through fifth gears, low-friction transmission oil, optimisation of steering servo assistance and engine management optimisation.