Also, towing heavy, actually heavy, not 1200 kg, went away in cars about 1990. Emissions regulations, really. 1985 olds, Chrysler, could safely yank around a 4500 kilogram horse trailer. That all went away, now it's cars that could maybe 1000 lbs amd trucks that can pull 5 to 15000 kg loads. Btw, the old auto tow transmissions like the hydromatic 400, didn't have a lock up at all. Jaguar used to buy them.from Chevy for use in the old XJS v12s .