Breaking in a new engine

[Kuripot]

I'm driving a new Hyundai Accent and trying to break it in correctly. The first tank of gas was used primarily around town and when i did take it on the highway I tried to vary my rpms as much as I could. On the second tank I was using it for my 35 mile trip to work every day and haven't been varying the rpms much. What is the concept behind varying rpm and how does that improve the break-in process on an engine? I read where keeping the engine at a constant rpm during break-in can glaze the cylinder walls and keep the rings from seating properly. Is that everybody elses understanding?

The manual suggests keeping rpms between 2000-4000. Sixty mph is at about 3000 rpms and where I like to drive it on the interstate for the best mileage. I guess I should be running it up to 75 mph and back down to 60 occasionally. That's pretty annoying to other drivers for the first 1200 miles. LOL