Production years: 1961 - 1968

For the 1960s Jaguar needed something new for the flagship saloon in the range so the Mark X took on the mantle. Introduced at the British Motor Show in 1961, apart from the existing 3.8 litre XK engine (now equipped with triple carburettors). the car was all new. A monocoque body shell of vast proportions, carrying the accolade of being the widest production saloon ever produced in the UK at the time, the styling incorporated a four headlight frontal treatment with shallow forward sloping grille and a one piece hinged bonnet. With bulbous sides to allow extra interior width in the car, an extra larger boot area and massive sills to retain rigidity, the car was stylistically still very attractive.

Built with Jaguar’s prime USA market in mind, the car even carried 14” wheel rims, the norm for American cars at the time. It was perhaps because of its immense size that the car wasn’t as popular as Jaguar would have hoped. Too wide for many British roads and private garages, and too trans-continental in looks to suit the Americans concept of a luxury British saloon.

Nevertheless the car was a superb, well equipped model which would finally see off most British competition from the likes of Armstrong Siddeley, Humber and even Daimler.

The model was upgraded with the 4.2 litre engine in 1964 along with an all synchromesh manual gearbox, improved brakes and power steering

Model Summary

Model Type:

Mark 10/420G/DS420

Production Dates:

1961 - 1968

Engine Range:

3.8 Litre Saloon

4.2 Litre Saloon

0 - 60 mph:

3.8 Litre Saloon - 9.1 seconds

4.2 Litre Saloon - 9.9 seconds

Top Speed:

3.8 Litre Saloon - 119.5 mph

4.2 Litre Saloon - 121.5 mph

Mark 10 Technical Specifications

Technical Information

Engine Statistics

  3.8 Litre Saloon
Engine (cc) 3781
Bore and Stroke (mm) 87 x 106
Compression Ratio 8:1 (7:1/9:1 optional)
BHP 265
@ RPM 5500
Torque (lb ft) 260
@ RPM 4000
Fuelling 3x SU carbs
  4.2 Litre Saloon
Engine (cc) 4235
Bore and Stroke (mm) 92.07 x 106
Compression Ratio 8:1 (7:1/9:1 optional)
BHP 265
@ RPM 5400
Torque (lb ft) 283
@ RPM 4000
Fuelling 3x SU carbs

Engine Performance

  3.8 Litre Saloon
Top Speed 119.5 mph
0 - 60 mph 9.1 seconds
Fuel Consumption 14.1 mpg
  4.2 Litre Saloon
Top Speed 121.5 mph
0 - 60 mph 9.9 seconds
Fuel Consumption 14.5 mpg

Model Specifications

  3.8 Litre Saloon
Transmission 4-speed (3 synchro) BW 3-speed auto
Wheel Size (in) 14, steel
Suspension (Front) Ind semi-trailing wishbones, coil springs, ant-roll bar
Suspension (Rear) Ind lower wishbone/upper driveshaft link, radius arms, coil springs
Brakes 4-wheel disc, rear inboard
  4.2 Litre Saloon
Transmission 4-speed (all synchro) BW 3-speed auto
Wheel Size (in) 14, steel
Suspension (Front) Ind semi-trailing wishbones, coil springs, ant-roll bar
Suspension (Rear) Ind lower wishbone/upper driveshaft link, radius arms, coil springs
Brakes 4-wheel disc, rear inboard

Model Dimensions

  3.8 Litre Saloon
Length (in) 202
Width (in) 76
Height (in) 54.75
Wheelbase (in) 120
Front Track (in) 58
Rear Track (in) 58
Weight (Cwt) 37
  4.2 Litre Saloon
Length (in) 202
Width (in) 76
Height (in) 54.75
Wheelbase (in) 120
Front Track (in) 58
Rear Track (in) 58
Weight (Cwt) 37

Optional Extras

  • Choice of three radio installations with or without rear parcel shelf-mounted speaker
  • Electric radio aerial
  • Wind-up radio aerial
  • Electrically operated windows (front and rear)
  • Laminated windscreen
  • Witter tow bar
  • Heated rear screen (earlier cars)
  • Front seat belts
  • Choice of radial, town and country, or whitewall tyres
  • Borg Warner automatic transmission
  • Overdrive (for non-overdrive-equipped manual transmission cars)
  • Fire extinguisher
  • Sundym tinted windscreen and side windows
  • Wing mirrors
  • Integrated ignition/starter switch to steering column
  • Limousine appointments (only available on ordering a new car)

Chassis Numbers

Model Driver Side Chassis No. Commenced Number made
Mark X 3.8 RHD 300001 9129
Mark X 3.8 LHD 350001 3848
Mark X 4.2 RHD 1D50001 3720
Mark X 4.2 LHD 1D75001 1960
420G RHD G1D53720 5429
420G LHD G1D76961 1125

Club Events

P1130322
420 G Saloon

Model Contacts

Nigel Thorley

Nigel Thorley

Magazine Editor & Seminars

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