Thank you both! The link Rich supplied indicates I'm running at 17 mph at full speed, so I believe my question has been answered. I'll continue with my layout and watch how it handles the modest grades I have planned. Thanks again!

I'm running a brand new Spectrum "70 ton three truck climax loco (DCC)" on Bachmann EZ track using an MRC 200 Tech 4 controller. At the maximum speed setting the engine moves very slowly around a short oval. I'm concerned that when I lengthen the track and add some grades for the engine to climb, it's going to stall out. The MRC offers 15.5 VDC with 17VA so I'm assuming power availability isn't my issue. Any suggestions of what my issue may be?