Paul hit it pretty well that the tractive force curves drive the physics engine. As for being "cheated", pretty much any time you are making more than 10 MPH up Mullan, you are doing great! "Into the Storm" will REALLY test your patience of crawling along at slow speed if you use the Stable version and all the settings described in the route manual.

deltapooh, your performance issues are a bit perplexing to me with those specs. I have an i3 and do not experience crashes like that. Feel free to send me an OR Log file by Private Message so I can take a look at your game settings, I'll see if there is anything we can do to up your performance.