OK. I've looked at all the posts on break-in period and one that referenced an FAQ on the topic (but the FAQ topic appears to have been deleted).

I'm a little torn... I read this link

http://www.mototuneusa.com/break_in_secrets.htm

and I'm wondering whether or not this applies.

Three questions in particular:

1) Other than noticeable engine oil loss (due to poor seal) does anyone have any evidence to suggest that running it hard or manufacturer's recommended break-in is better (i.e. has anyone had to break the engine down and seen the pistons)?

2) If I'm passed the first 100 miles, would it be to late to run it hard?

3) Is there anything unique to the G35 Coupe engine in particular that would result in different conclusions (i.e. is this all about sealing the rings only)?

If I missed a link please let me know. FYI... The FAQ has only 1 post under break-in and I did read all posts via a search and I didn't see any evidence (as opposed to opinions) that would suggest which is better (it might be because there really isn't a good way to know unless you break down the engine and no one has done that)

 

Just my personal opinion. I have had a few new vehicles and always broke them in as per manufacturer's recommendations. I have raced (1/4 mile) some of these cars and have still put high mileage on a few of them before I replaced them. None of these cars burned oil, or blew up on me. The only abnormal maintenance was on a 440 Cuda that I held the record with at my local strip. The valve guides became worn and I had to have some head work done. Other than that I never had any unusual mechancal problems.
So, I will continue to break my motor, drive train, and brakes in gently as per the manual. I have just completed breaking in my 05G35X, it took 4 weeks to get the recommended 1200 miles.

 

The only reason people suggest running it hard is to set the ecu to maximum performance, which can easily be reset at anytime. I would suggest taking the first 500 slow, get a oil change, and have at it..

 

If you follow the link above you will see that there are other reasons.
& I'm sure you will get passionate responses from both camps

From my expeience, nothing conclusive, but.....

I have broken in my last 3 cars that way.
I usually have about 150k on them when done.
I have never had any mechanical problems.
All three never required oil between changes.
(Ford Explore V8, VWPassatt 1.8t, Toyota Highlander V6 and now my G)

 

inTgr8r,

Thanks. Glad to find someone who has used the "run-it-hard" method. The article is very convincing and what surprised me as that if the article is credible you actually get a better seal. The fact that you have never needed to top off oil in between changes would seem to indiate that it works (well, at a minimum, at least it doesn't blow out the seals). I'm marginally technically inclined and the reasoning in the article makes sense to me.

Any opinion, if I have 100+ miles on my car, is it too late?

 

One other data point/poll that would be interesting... for those that use the run-it-hard versus manufacturer break-in method, have either had their oil tested regularly. If so, how much contamination was reported?

 

For the most part, I take sides w/ the harder break-in camp. I broke my X in by the pedal to the metal (judiciously of course) method, as I have done often in my 55 yrs. of engine and vehicle building. In the case of my X, I went at it as described in the link and at 1,500 mi. threw in a K&N filter and went to Mobil 1. I would say it might be of interest to take a compression reading from each of the cylinders and compare notes w/some of you out there who care about such things ????? Anybody game? Note: I will be HAPPY to confirm my findings by taking pics of the Snap On guage. Could put a new slant on an old debate....JBX

 

I usually go with the "keep under 4k RPM until 1k miles, switch to synthetic after 15k miles" and have not had any problems getting an easy 100k out of those vehicles with no engine trouble.