Last year I bought a 97 mustang with low 32,000 miles, I purchased an extended warranty (Ford EXP plan), 4 years/48,000 miles, the owners manual calls for 5W-30, would using 10W-30 void the warranty? Also I noticed that when I took the car to the dealership for oil changes they were going to put 5W-20 in it, they told me that 5W-20 is not only for new fords but recommeded for all newer fords (97+). I do the maintaince on my other two vehicles but would rather have the maintaince done on this car at the dealer and keep the paperwork in case something came up.
Thanks
Thanks