Bob, Door pistons and others are rated in Newtons. 1 Newton = .224809lb's thus a door piston is 1200 newtons = 269.77lb's I louver piston is 130 newtons which ='s 29.23 lb's 1 bar = 14.504 lb's, so 5 bar's of pressure = 72.520lb's of pressure. John Hervey www.specialtauto.com << For those of us, who don't remember how to convert bar to psi, how much is 170 bar in PSI? >>