MattstaF6

Personally I hate dealers and think they are rip off artist. I would make the change it and put in a 40 weight fully synthetic oil or even something thicker. Dealers always put cheaper semi-synthetic stuff in and usually thinner oil than recommended. Most tuners and performance place around would not put any other oil in but a fully synthetic 40+ weight oil in these cars especially if its been modified. I use Castrol Edge 10w-60 in my Typhoon and that's what was recommended by 2 Castrol technicians and 3 Performance shops. Guys have done oil analysis tests and it has showed that thinner oil doesn't protect the same.

I do mine at 10,000km's with Castrol Edge oil. I don't think 5,000km is required unless you drive hard often. Also do your diff every 30,000km. Its not expensive. Whatever you do don't go to Ford to get your car serviced. Way overpriced and they use cheap oil most of the time