My test has been, will it get peanut butter off a butter knife. My wife will put the knife straight into the dishwasher with peanut butter on it and so far none of the dishwashers have won that challenge.
bingo... mine toooo... my wife just puts the knife in the dishwasher and 9 times out of 10, there is still residue left.... i saw on this old house an appliance guy saying that to help give the dishwasher a boost, he turns on the faucet hot water b4 starting the dishwasher ... and he said that todays drying cycle is not as efficient as days gone by.... energy efficiency ....
