- 478

- United Kingdom
- GMW
Now this is news to me. I didn't know the horsepower increases after 600miles! I usually buy or plan to buy 2 versions of the same car. One completely stock without a single change. Though I found I had to do the oil change on a brand new C63 to get the 457hp as per the manufacturer specs. I guess I will drive it for more than 600 miles and find out what happens. cool!You don't have to do it, it's completely optional. Things to take note of , GT5 also has a break in period for engines, after about 600 miles you get a horsepower boost that stays until your get engine degradation sets in, then you have to do an engine rebuild, basically putting a new engine in the car if you want to get your power back.