When I test drive cars, I often put my foot on the gas pretty hard at least a couple times. I assume other test drivers are doing the same. Does this mess up the engine's break in period?
engines today have a very quick break-in period. within a few dozen miles, within about an hour of driving really. tolerances being what they are i wouldn't worry about it.
...the "no-no" activity is driving at exactly the same rpm for an extended time within 500-1000 miles. Doing that tends to "seat" cylinder rings at a single engine rpm, which is NOT good for long life.
...full-throttle blasts and screeching brakes are OK if done in moderation, as they expose the engine to events likely to occur in real life...just not all the time.
So is it ok to take a long freeway drive, like 100's of miles, on a brand new engine as long as you don't use the cruise control, and vary your speed throughout the drive?
It is certainly OK to take a freeway drive of 100s of miles during break-in. Many have to do it to get their car home from the Dealer. Constant speed is not a big issue, but constant RPMs are. Make sure the RPMs vary somewhat over the first few hundred miles. Also try not to jump on the brakes too hard, until they have had a chance to break-in a little as well.
Ahh, it's the RPMs. Thanks for the clarification. Yea, I might end up getting my cruze from a dealer that is like 50 miles away by highway. I have to vary those RPMs.