I just used google to convert the US quarts into litres, so according to thed escription, this should be for anything from 15 litres. Our cars only have 5 litres, so perhaps I should look for a heater suitable for a smaller volume. Knowing my luck the smaller heaters will be 110v only. I suppose they could be run from a transformer but that's extra hassle. Or do all US cars have massive engines with massive coolant volumes?
I suppose a CH pump would be ideal, after all, they are designed to move hot water around pipe work but they are a bit bulky. I guess I'd have to see if there was room to include one.
I could not find a manufacturer's web site but did find a few reviews claiming the heaters died pretty quickly but other people replied that failures were due to mounting incorrectly, so that the hot water did not rise.