I was always warned not to use pressure washer on wire wheels as this could force water into the gaps between the spokes and the rim and would contribute to rust forming. This may only apply to CWW and not so much to Stainless Steel.
Steve: I was given similar advice, for the same reason, by a well respected Morgan dealer. I tend not to use a pressure washer on any part of my 4/4. I much prefer a gentler approach and use a watering can to remove soap suds.
