Severe duty for my Hyundai 2.4L GDI engine is 3,750 miles (oil type not mentioned in owner's manual) ... Curious if using M1 5W30 EP if "severe duty" (i.e. suburban driving of various trip lengths) the milage could be extended to 5,000 miles or even 7,500 miles using again M1 5W30 EP with a Fram Ultra oil filter ? Of course , a UOA would confirm but just trying for an educated guess in a well kept engine using a top synthetic oil and oil filter to go past 3,750 miles ? *Also to note , Hyundai Service Manager was emphatic to tell my wife : "Any large city / suburban driving is ALWAYS going to put you in the "severe service" category - whether you get your oil changed here at Hyundai or any where else - just be sure to get it done by 3,750 miles".