jay

can anyone clear this debate up? how long is the break in period for a 4.6L , ive been told 500 miles and even 10k, and how long before i can switch to fully synthetic oil, ive been told that the rings will never seat if you put synthetic in before motor is "broke in" i have also been told that before motor is broke in to never take it over 5000 rpm, the last thing i would want to do is hurt my motor, so any input on this matter would be great. also was wondering since this is my first alum block, are they able to re bore cylinders on them, and how much can they be bored, do they just put new cylinder sleeves in or what?

Marty256

5K according to the dealer.

Birdieman4

Take out that blended stock motor oil at 500 miles. Put in a fully synthetic oil of you choice (I use Mobil), and vary the rpms until around 1000 miles. After that, have at it.

racin4christ

well the motors are already spun at 2 to 3000 rpms for several hours before they are put in the cars. But i think that 1000 is a safe mark. I have done some wide open driving and i have900 miles on my stang already but i think that I should have taken it a little easyer for the first 1000 miles. I did run the motor harder than I should have. Im just trigger happy with my right foot. oops. and i just got it on saturday. btw on my cardomain.com site i have the story of how i got my stang. Some guy ordered it but ran into financial problems and i happend to find it on a lot and just wanted to test drive one. and walked away with it at the end of the day.

nanaki

at least with the 05 GTs, you know how your car has been driven for every mile on it. since you can't really find them on a lot to test drive. all the 04s and what not on the lot that have like 50-300 miles on them, you know whoever test drove those was opening it up. even while it wasn't warmed up. kinda scares me since my car had a tad over 300 miles on it when i got it.

algregory

I'm an avid Red Line 20-50 user. My GT comes next week. I've already called Red Line for their recomendations. They said use the Ford recomened viscosity and to wait for 2k miles. They said my trusty 20-50 will confuse the computer.

I'm also an avid "Tufoil" user. www.tufoil.com The people that custom built my BMW motor said it is good stuff. Its a four banger, I drive it hard after warmed up. 125k on the build, some 15 sets of premium race tires since the build, runs like a swiss watch, turbine smooth and strong. I use 8 ounces of Tufoil at each oil change. I'm going to call Tufoil and see what they say before I put in the Mustang.

I'm going to break in car per factory recomendations. Leaving on 23rd for a trip from San Jose, CA to Cambria CA via Hwy 1. Should be a nice break in, but there are going to be some sections in which I'll reall wish I COULD NAIL THE THROTTLE!!! I'll be missing my '04 Yamaha FJR1300ABS during those moments!

In my Motorcycles, my choice of oil is Motul 300V 15-50