W.O.'s favourite — the six-cylinder Bentley that won Le Mans in 1929 and 1930 and outshone the Blower on the track.
The Speed Six was the high-performance version of Bentley's 6½ Litre, with raised compression, twin SU carburettors and revised camshaft for around 180 bhp. Two Speed Sixes — most famously 'Old Number One' driven by Woolf Barnato — won Le Mans outright in 1929 and 1930, the latter year with Birkin's Blower acting as decoy. Around 182 Speed Six chassis were built, most carrying open coachwork by Vanden Plas, Gurney Nutting or H.J. Mulliner.
The most successful racing Bentley of the W.O. era and the car the company's founder personally rated highest.
| Variant | Years | Production | Notes |
|---|---|---|---|
| Speed Six (production) | 1928–1930 | 182 | Higher-output version of 6½ Litre; majority bodied as tourers. |
| Le Mans works cars | 1929–1930 | — | Won Le Mans 1929 (Barnato/Birkin) and 1930 (Barnato/Kidston). |
For pre-war and vintage cars such as the Bentley Speed Six, provenance is paramount. Chassis and engine number matching, period coachbuilder records, factory build sheets where available, continuous ownership documentation, original handbooks and any competition or concours history are the foundation of value. Verified Speed Six engine and chassis, original open coachwork, Le Mans-eligible documentation and continuous registry history.
The 6,597cc straight-six is robust but heavy; check oil pressure, valve clearances and twin-magneto ignition condition. Gearbox synchroniser-free 'crash' shifting requires technique and well-set linkages. A pre-purchase inspection by a recognised marque specialist should include compression and leak-down testing, magneto and ignition checks, chassis straightness and frame survey, axle and steering wear assessment, brake system review (mechanical or hydraulic per period), and an extended road test on varied terrain to expose carburation, cooling and gearbox issues that only emerge under sustained running.
Pre-war coachwork is rarely truly original after a century of use. Establish whether the body is original to the chassis (period photographs, build records, coachbuilder plates), whether it has been re-bodied at any point, and the standard of any restoration. Quality of timber framing, ash health, panel beating and paint depth are all critical. Concealed structural rot, re-bodies presented as original, and 'tribute' cars built on later or unrelated chassis must be priced accordingly.
Original Speed Six chassis with Vanden Plas Le Mans-style or H.J. Mulliner short-chassis coachwork; saloon cars and re-bodies trade at a discount. For vintage cars, event eligibility — Mille Miglia, Goodwood Revival, Pebble Beach, VSCC events, Le Mans Classic — can underwrite a substantial proportion of market value. Verify FIA/FIVA papers, period race history where claimed, and the car's standing with the relevant marque registry before purchase.
Regional ranges authored independently — each reflects its local market, not an FX conversion
Vintage cars require disciplined preventive maintenance: lubrication regimes, magneto service, carburettor synchronisation, brake adjustment, and timber and trim conservation. A car used regularly and serviced annually by a specialist will outlast a stored example neglected for decades.
Strong global specialist network through Bentley Drivers Club; parts available through marque suppliers. Confirm the availability of marque specialists, period-correct fasteners, coachwork trim, instruments and tyres before committing. A car requiring fabricated one-off parts will absorb time and cost that a similar example with active specialist support will not.
Each region quoted in its local currency — independent market readings, not FX conversions
Speed Sixes are increasingly recognised as the most desirable W.O.-built Bentleys after the Blower. Open-bodied Le Mans-style cars lead values; saloons offer comparable usability for materially less money.
| Date | Auction | Car | Mileage | Result |
|---|---|---|---|---|
| 2024-09-07 | Bonhams Goodwood Revival | 1930 Speed Six Tourer (Vanden Plas) | — | £1,840,000 Sold |
Le Mans heritage, finite production, and W.O. Bentley's personal endorsement underpin sustained demand.
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Register interestThe valuation figures in this guide are for research purposes only and do not constitute financial or investment advice. See our full disclaimer.
