So I've been thinking that I'll use regular motoroil (what the car comes with) for the first 500 miles or so to break in the new '05 motor, then switch to synthetic. I don't want to use synthetic to break in the engine because I've heard synthetic oil is too slippery and certain engine components won't seat properly, causing oil burning.
So what do you guys think? If you're using synthetic, are you switching right away, or breaking in the motor, then switching?

 

Most say break it in with regular motor oil just to seat the bearings and rings. I used synthetic Mobil 1 in my 89 GT from 17k through 137k miles. It didn't use anymore oil between changes at 137k than it did at 17k. Plus I got excellant performance and it ran cooler in the simmer. I put Redline Synthetic in the rearend and gearbox too.

 

i was thinking the same thing. glad u asked the question.

B)

 

I am probably going to use the recomended Motorcraft 5W-20 for the first 12-15K then make the switch to synthetic!