- Stock #232551 - Buyer Alert! 2017 Tiffin Allegro Bus Available! ALL Electric! King Bed, W/D, DishDrawer, Full Bath & Half. 450HP Cummins Diesel 28,770 Miles! WarrantyThis 4 Season, 2017 Allegro Bus 45OPP, by Tiffin is in impeccable condition. S