Aston Martin has rolled out a series of updates to its Vanquish and Rapide S sports cars for the 2015 model year, including a new eight-speed automatic gearbox.

The new Touchtronic III eight-speed unit from transmission specialists ZF is offered in both the Vanquish and Rapide S.

Minor changes to the engine also see peak power increases of 3bhp in the Vanquish to 568bhp and 2bhp in the Rapide S, now with 552bhp and 10Nm more torque (to 630Nm at 5,500rpm).

As a result, the 0-60mph time for the Vanquish drops from 4.1 seconds to 3.6, while the Rapide S completes the same sprint in 4.2 seconds, down from 4.7.  Both cars are now capable of top speeds over 200 mph.

Both cars are more frugal, too, with the CO2 figures for the Vanquish down by around 10% to 298 g/km, with the Rapide S recording a similar fall to 300 g/km.  Both models achieve an 11% reduction in fuel consumption, with an EU extra-urban figure of 31 mpg.

The new transmission is 3% lighter than the old unit, and can change gear in just 130 milliseconds.  It features Drive, Drive Sport, Paddle Shift and Paddle Shift Sport modes to alter its behaviour according to driver mood.

A new multi-ratio down-shift function can be activated by holding the down-shift paddle, and this instructs the gearbox to select the lowest possible gear during braking.

An Adaptive Drive Recognition (ADR) feature alters shift points according to driver style, with the function being reset each time the car is unlocked.

Other changes include a new Bosch engine management system, a revised torque tube to reduce cabin noise, updates to the DSC stability control, and new parameters for the steering control unit.

The dampers in the Vanquish have been stiffened – by 15% at the front and 35% at the rear – while the Rapide S receives larger front brakes.  Both cars now use a retuned brake booster and 20% stiffer rear suspension bushes.

Styling-wise, there are new ten-spoke alloy wheel designs, new exterior paint colours (including Diavalo Red previously limited to the V12 Zagato), and new interior trim colours.

Pricing hasn’t been announced, but sales are expected to begin in Q3 of 2014.