Tractor test: Case IH JX90U Maxxima She’s a jammin…… with a capital ‘J’. From whatever angle there’s something rather chic hip and trendy about the JXU a Case IH tractor that positions its bits in all the right places to create a look that put simply just works. To provide a fuller assessment of what goes on under that neat little red bonnet we test the flagship-but-one model the 65kW/88hp JX90U