What does MPH indicate?

[lx mike]

Is it because of my traction problems and does it also indicate that my engine has the potential of 12's

yes. look at your 60' times. i dug out some of my old time slips and i was running 13.1-13.2 with a 60' time in the mid 1.8's. with the same combo and just switching to slicks i am running 12.7's with 60' times in the mid 1.6's!