The MGA instrument panel features a speedometer and rev counter flanking a central radio speaker grille, with smaller fuel and combined oil pressure/temperature gauges to either side. All instruments had black dials with white figures and markings, white pointers with chrome centres, individually rim-lit, and mounted in chrome-plated bezels. They were manufactured by Smiths but marked British Jaeger.
Instrument Changes
The original 1500 instruments had stylised typography. From chassis 14090, simpler typography with ladder scales was introduced on all instruments. The speedometer was originally marked to 110 mph, the later type to 120 mph. At least 23 different speedometer types were used across MGA production, calibrated for different rear axle ratios (4.3:1, 4.1:1, and competition ratios) and different market requirements (mph and km/h).
The rev counter came in three types: the original 1500 to 6,500 rpm, the later pushrod to 7,000 rpm, and the Twin Cam to 7,500 rpm with higher amber and red sectors. The oil pressure gauge scale changed from 0-25-50-75-100 to 0-20-40-60-80-100 at chassis 14090. A Centigrade water temperature gauge was introduced from chassis 57574 on left-hand drive cars.
Fuel Gauge and Sender
The fuel gauge operates from a sender unit in the tank. Both the gauge and sender must be matched to the car's electrical polarity, a positive earth gauge will read incorrectly with a negative earth sender, and vice versa.
Ordering Notes
When ordering gauges, the chassis number determines the instrument type (pre or post 14090), the speedometer calibration (rear axle ratio), and the temperature gauge scale (Fahrenheit or Centigrade). The rev counter type depends on the variant (pushrod or Twin Cam). Confirm the electrical polarity for the fuel gauge sender unit.