i dont know what milage you have but when i seen 99 if you do the math you most likely have somewere from 50 to 70,000 miles right?i hope im in the right ballpark so thats why i say 10w-30.
i allways started using 10w-30 at around 50,000 miles just for insurence but 5w-30 will work.also keep in mind if you use regular oil (non synthetic) then it tends to get thicker in the colder months so 5w-30 is fine but in the summer i would use 10w-30.but if you take our advice and use synthetic then you dont need to worry about it getting thicker or thinner.either way good luck!