8 gallon tanks?

[PaulGover]

I filled up my XJ6-III's tank for £40 last week. At today's prices, that's almost exactly 8 gallons into an empty tank. About the same for both left and right tanks. But AFAIK they were always 10 gallon tanks. (For US readers, this is all UK Imperial gallon, not the skinny American version.). This is a 1986 4.2 "Executive" spec. that was supplied for (I believe) US export though with UK specification.

Has anyone heard of either
1) a smaller fuel tank being fitted; or
2) a problem that prevents tanks either emptying or filling properly?

The car is in very good condition with no record of any work on the fuel system, and has only recorded 70,000 miles. (As an aside, it seems to have the wrong thermostat too - the temp gauge sits at about 5 degrees low, and I know there were two thermostats available and the XJ6 specified the higher one.)

Thanks for any comments.

[PPV]

Not sure about your car but generally a fuel tank will have about a gallon or so in the bottom when 'empty'. Which will make your tank 10 gallons.
Regards,