Otto Explains — Engines & Drivetrains

Iconic Bentley Engines & Drivetrains

Short Answer

Bentley engines moved from W.O. Bentley’s four-valve 3 Litre four and large straight-sixes to a V8 introduced in 1959, later 6.75 litres and turbocharged, which lasted until 2020. The 6.0-litre W12 powered Bentleys from 2003 to 2024 and brought all-wheel drive with the Continental GT. Today’s cars use 4.0-litre V8 and hybrid powertrains, and the Torcal of 2026 is fully electric.

What made the first Bentley engine advanced?

Its cylinder head. The 3 Litre’s 2,996 cc four-cylinder engine had four valves per cylinder, twin spark plugs and an overhead camshaft driven by bevel gears. It was a monobloc design with no separate cylinder head, which did away with the head gasket, a part that could otherwise expand and fail. The 3 Litre was built from 1921 to 1929.

Why did W.O. Bentley prefer bigger engines to superchargers?

He believed the sensible way to more power was more capacity. The 6½ Litre of 1926 had a straight-six of 100 mm bore and 140 mm stroke, almost 6.6 litres, giving 147 bhp; the Speed Six of 1928 raised that to 180 bhp, or 200 bhp in racing form. The 4½ Litre replaced the 3 Litre in the same spirit. The Blower went the other way: Tim Birkin added an Amherst Villiers Roots-type supercharger, lifting the 4½ Litre from about 110 bhp to 175 bhp, against W.O.’s wishes.

What powered the 8 Litre?

A bigger version of the 6½ Litre engine. The 8 Litre’s straight-six was bored out from the 6½ Litre unit, and W.O. Bentley, whose last design for the company it was, called the result a “dead silent 100 mph car”. Only 100 were built.

What engines did Rolls-Royce-era Bentleys use?

New six-cylinder engines with no link to Cricklewood: the Derby 3½ Litre of 1933 shared no parts with earlier Bentleys, and a 4¼ Litre engine was offered from 1936. The Mark V used an overhead-valve 4,257 cc six with independent front suspension and a four-speed overdrive gearbox. The post-war Mark VI kept 4,257 cc but with overhead inlet and side exhaust valves. For the R-Type Continental, the 4,566 cc six was tuned from 140 to 153 bhp, and a 4,887 cc engine came later.

Where did Bentley’s V8 come from?

From the S2 of 1959, which introduced Bentley’s first V8, an all-new 6.2-litre aluminium engine from a team led by Harry Grylls. The T Series of 1965 used the 6.23-litre V8 with a four-speed automatic gearbox, rear-wheel drive and self-levelling suspension. The engine was later enlarged to 6.75 litres and stayed in production until the Mulsanne ended in 2020, which makes it Bentley’s longest-serving engine series, with more than 36,000 built.

How did turbocharging change the 6.75-litre V8?

It turned it into a performance engine. The Mulsanne Turbo of 1982 had 50% more power than its predecessor, and the Turbo R used a Garrett AiResearch T04 turbocharger for 298 bhp, with fuel injection and anti-lock brakes added in 1987. Gearboxes changed slowly: the 1984 Continental still used a GM400 three-speed automatic. In its final form, in the Mulsanne of 2010, the twin-turbocharged V8 gained variable cam phasing and cylinder deactivation, with a ZF eight-speed automatic driving the rear wheels.

Why did the Arnage start with a BMW engine?

Because the car was engineered while Vickers still owned Bentley, which put it on sale in April 1998 powered by a twin-turbo 4.4-litre V8 derived from a BMW design. Volkswagen’s new management then brought back Bentley’s own big engine: the Red Label version used the turbocharged 6.75-litre V8, and the BMW-engined car, by then called the Green Label, left the range in 2001.

How does the Bentley W12 work?

It is in essence two narrow-angle V6 engines sharing one crankshaft, a layout that makes the 6.0-litre twin-turbocharged W12 24% shorter than an equivalent V12; Otto compares inline, V and W layouts in how engine designs differ. Introduced in the Continental GT in 2003, it was redesigned for the Bentayga in 2015 with direct and port injection, twin-scroll turbochargers and cylinder deactivation. More than 100,000 were hand-built in Crewe before production ended in 2024, and the final version, for the Batur, produces 750 PS and 1,000 Nm.

When did Bentley adopt all-wheel drive?

With the Continental GT of 2003, the first Bentley with all-wheel drive. It used permanent four-wheel drive with a Torsen centre differential and a ZF six-speed automatic gearbox. The Bentayga also uses Torsen all-wheel drive, and at its launch in 2015 it introduced 48V active anti-roll control, which Bentley describes as a world first.

What powers today’s petrol and hybrid Bentleys?

A 4.0-litre twin-turbo V8 family. The V8 joined the W12 in the second-generation Continental GT and can run on half its cylinders when full power is not needed; current Bentaygas use it with 550 PS, or 650 PS in the Speed. The Bentayga Hybrid of 2018 paired a 3.0-litre V6 with a 94 kW electric motor and a 17.3 kWh battery. The Ultra Performance Hybrid of 2024 combines a new 4.0-litre V8 of 600 PS with a 190 PS electric motor for 782 PS and 1,000 Nm, driving all four wheels through an eight-speed dual-clutch transmission, with about 81 kilometres of electric range. The Supersports goes the other way: a non-hybrid 666 PS V8 and, for the first time in a Continental GT, rear-wheel drive.

How does the electric Torcal drive?

With two permanent-magnet synchronous motors and a 113 kWh battery running at 800 V. The core Torcal has 821 PS and the Torcal S up to 888 PS, with a range of up to 600 kilometres on the WLTP cycle, and All Wheel Steering is standard. It is Bentley’s first fully electric car, unveiled on 23 September 2026.

What should Bentley owners keep in mind?

That a Bentley badge says little about what is under the bonnet. Depending on the year and version, a Continental GT can carry a W12, a twin-turbo V8 or the V8 hybrid, and Bentley itself notes that equipment differs between markets and can change at short notice. Identify the exact engine, gearbox and drive system from the car’s own records before ordering parts or chasing a fault, follow Bentley’s maintenance schedule for that specific car, and treat a scan as a starting point for testing, not as the answer. At AutoTronix, mechanical work on engines, gearboxes and drivetrains belongs to Garage, electronic diagnosis to Lab, and high-performance and luxury cars are PERFORMANCE’s speciality.

Common Questions

  • When did Bentley end W12 production? In 2024, after more than 100,000 had been hand-built in Crewe since 2003. A V8 hybrid took its place as Bentley’s most powerful powertrain.
  • Which Bentley first had a V8? The S2 of 1959, with an all-new 6.2-litre aluminium V8.
  • Does every new Continental GT have all-wheel drive? No. The Ultra Performance Hybrid models drive all four wheels, but the limited-edition Supersports is rear-wheel drive.
  • What does Speed Six mean? It was the more powerful version of the six-cylinder 6½ Litre, introduced in 1928 with 180 bhp. Bentley still uses Speed for its performance models today.

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