[zaimon]

...we had a Tribute come right off the truck and the engine siezed up with only 2 miles on the odo. That's Ford engineering for you.

More like Ford manufacturing, I've had an '01 Tribute for 50,000 miles with no major problems. Likewise, the Mazda6 uses the same block that the Tribute 3.0 uses but is manufacturered at a different plant.

The most I know about break in is to vary the RPMs for the first 500-1000 miles and not to maintain a constant rate of RPMs over a long period of time.

 

[zaimon]

Maybe try rotating between the slow lanes and fast lanes?

Something to try would be to take a driving break halfway through the trip to eat or shop. Let the car rest and get back on the road.