The latter gauges are Thermal Bi-metallic strip; the early ones are basically Electromagnetic or 'Moving Iron'. A lump of iron on the pointer is affected by a varying magnetic fields and respond instantly to bouncing of the transmitter.ManyMinors wrote: ↑Wed Feb 18, 2026 8:38 am To be fair, you can't expect such old cars to have very accurate gauges. The petrol gauge in those early cars do a reasonable job but they were old fashioned and basic even at the time. In 1964 - which is still over 60 years ago(!) the gauges were updated to the black faced instrument and fitted with a voltage stabiliser. This gave a slower needle movement and greater accuracy and were considered quite an improvement but it's all about getting used to the car isn't it. As others have suggested, make a not of the mileage when you fill up and you'll soon get to know what the car will cover on a tankful. You'll get used to it
I've driven Morris Minors for well over 50 years and have never run out of fuel yet. They have a relatively small tank by today's standards and with fewer petrol stations around, you do have to keep an eye open on longer journeys.
Hence the latter ones have a dampened movement, due to the response of the heated metal strip.
