The Speed's twin-turbocharged 6.0-litre W12 engine produces 633bhp, up from 626bhp in its predecessor, and an extra 15lb ft, making a total of 620Ib ft.
This extra torque is applied throughout the rev range via reoptimisation of boost control, which raises maximum torque delivery from 2000-5000rpm and improves acceleration. The Speed achieves 0-60mph in 3.9sec, shaving 0.3sec of its predecessor.
Bentley has also introduced a Continental GT Speed Black Edition, which offers buyers a high-gloss black finish to exterior brightwork, including window openings, as well as black 21in wheels and red or black brake calipers.
Other colour accents are available both outside - for example, on the front splitter and side skirts - and inside, with contrast leather to match the external shades.
Paul Jones, product line director for Continental GT, said: “We have developed the GT Speed Black Edition to meet demand from customers for a model in the Continental line that offers both increased sporting capabilities and instantly recognisable styling cues. The Black Edition has a subtle but purposeful look that is backed up by exceptional performance.”