My sender has arrived today after a several days in the Christmas mail system. The resistance values in the specification show 0 - 90 ohms but the real values of both senders are 3 ohms full and 75 ohms empty with a linear change between. As mentioned by "Dab", it gives you about 10 lt reserve when 0% is indicated, far more useful indications. Why don't they fit the 280mm unit from new?