Being old school, I have always taken my time breaking in new engines up to 1000 miles. When reading the 5.0 manual, it states to not take it full throttle until over 100 miles and not race or tow with it till 1000 miles. I got my 2012 with 3.2 miles on it and did not take it over 4000 till a tad over 100 miles and now with around 200 miles on it, I take it to 6000 around once a day but have never gone to redline. I know that there seems to be two schools of thought : One, take it easy up to around 1000 miles and Two, run it like you just took it to seed the rings in quickly and the way you want to drive it. My question, is there any evidence other then opinion on the 5.0 and which is the best procedure for the 5.0.

 

What makes a difference is running it for an extended period of time at high rpm.

You can redline it, just don't stay there.

 

I know I don't have a 2011 yet, but the day I rolled off the lot with my 2010 I drove it like I stole it. I haven't yet had a single problem from it, other than brakes... I drive a car that I intend to drive. (note this isn't my daily anymore)

 

One of the builders here, I forget if it's Steeda or maybe Rehagen, do an initial break in of maybe 100 mi. and check the compression, etc., then the cars are prepped and sent out on the track! So far they haven't had any engine problems with a "7000 rpm break-in".

 

I took it fairly easy with mine as it had 18 miles when I got it. At around 1k miles I drove from Utah to Florida and my car is just as good as the day I bought it

 

Drive it hard, vary the RPMs, and seat those rings right.

 

Picked mine up yesterday. I thought I might take it easy at first, but absolute power corrupts absolutely!

The owner's manual says to drive 100 mi before performing "extended wide open throttle maneuvers". To me, that means driving it "hard" on the street is fine. I'm not sure what my max RPMs have been, but I'm having fun with it, as my 14 MPG would suggest.

They also recommend varying your speed for the first 1,000 miles and waiting until then for any competition driving.

 

I hit the limiter 3 times before 1000 miles and the car runs great and uses no oil and it's an automatic.

 

Not saying it's right or wrong. But when I was building race engines for my own cars we would run it at 2K for 20 min to seat the cam and then beat that crap out of it and never look back. If it was going to blow up it was going to do it no matter how it was broke in. Not sure how that applies to street engines but when I got my car I just drove it how I wanted. I didn't beat on it but I also didn't baby it.

 

Pretty much the same with a regular engine. I am going to do that with the 302 I put in my 67. There is also something about getting breakin oil or finding an oil with high Zinc and running it at first. Then change it over to regular oil.