Ford, powerstrokes are different than the hi rail pressure dodge and chevrolets. They require hi pressure engine oil to fire the injectors , clean oil and possibly lighter weight oil in extreme weather will help starts . plugging them in warms the oil a bit and allows them to build pressure to start faster. good batteries are a must , when you check them make sure and disconnect one . any truck stop should carry a good anti gel additive , as welll keep clean fuel filters in them .