The BMW 3 Series-rivalling saloon can now be equipped with the four-wheel-drive T8 Twin Engine powertrain, which combines a 299bhp turbocharged 2.0-litre four-cylinder petrol engine with an 86bhp electric motor for a combined output of 385bhp and 472lb ft.
In this configuration, the S60 officially offers 36 miles of electric-only range, emits just 39g/km of CO2 and is capable of 176.5mpg combined on the WLTP test cycle.
The S60 T8 Twin Engine is capable of accelerating from 0-62mph in 4.6sec. The less potent T5 petrol model needs almost two seconds more to complete the same sprint.
The enhanced performance and efficiency commands a substantial premium over T5 models, with the T8 R-Design Plus available from £49,805. Business-in-kind tax rates for the new powertrain, however, are less than half those of petrol-only variants.
The T8 Twin Engine will soon be available with a Polestar Engineered upgrade, a software optimisation package that brings an additional 14bhp. It also sharpens throttle response, holds gears for longer and sends more power to the rear wheels in Dynamic driving mode.
There have been revisions further down the S60 range as well, with Inscription and R-Design trims replaced with better-equipped but more expensive Plus versions.
The now-entry-level trim, R-Design Plus, was previously priced from £36,750 but now starts at £37,935, with prices rising to £38,835 for Inscription Plus.
Standard equipment on all S60s includes adaptive LED headlights, front and rear parking sensors, sat-nav, heated front seats and dual-zone climate control.