[FONT=Arial]I will be picking up a new ‘left-over” 06’ MCS this weekend and driving it home at approximately 500 highway miles. I know I should obey the posted speed limits, but can any one recommend what the maximum speed I need to keep the MCS at during the break-in period if any? I did a quick search, but no results.[/FONT]

 

You said max, then 4000 rpm and 90 mph. Seriously

YD

 

Keep it below 90 and under 4500rpm...

Vary your speed and gears and you will be fine

 

Varying your speed is important. Just make sure no one is close behind when you decide to drop 5 or 10 mph for no apparent reason.

 

i too just picked up a brand new 06 mcs... and i am in love! per the manual it says, not over 4500 and don't exceed 100 mph.

i've got about 450 miles on it so far... i can't wait until the break-in period is over... only 750 more miles to go!

 

In my old neighborhood, the breakin period was generally 1 night.

 

They also say not to floor it after the break in period.

 

Thanks for the feeback!! I can hardly wait to pick up my MCS!!!

 

so how does the varying of speed help the break in?

 

Then there's the other school of thought...drive it like you stole it from day one...change your oil after 500 miles...

I get new GM company vehicles every 4 months and no one has ever told me to break it in nicely...yes, these are corporate vehicles that are being evaluated and then tagged afterwards by other employees for sale...

 

Just puts 'wear' on different parts of the gears.

 

Doing this will assist in the proper break-in of rings and bearings. Plus, it will make people look at your new ride.