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.”
Prices have not been announced for either variant, but expect the standard GT Speed to cost slightly more than the current model at £168,300. First customer deliveries are due in the summer.