The Chrysler tools can ratchet down the top speed, but they can't exceed the factory setting. If I recall correctly.
And if you ratchet it down, it's not easy to restore it... I just learned that the hard way...
When you hook the StarMOBILE up to the Sprinter and bring up the page on the Desktop Client, it looks like this:
I clicked on "Next", and tried to enter a couple of values that were higher than my factory setting (82)... wouldn't accept them. Then just to experiment, I entered 25mph. It happily accepted that, and the screen looked like this:
OK, experiment complete... it looks like it will take pretty much any number you enter, as long as it's below the factory-programmed default/maximum.
But then it got interesting, because when I tried to go back to 82, it wouldn't accept any number higher than the 25 it had accepted. A pop-up window said it would take any value down to 15, but nothing above the new high limit I had entered.
The key to resolving this lay in the fine print... look again at the first screen shot above... "to raise the speed back to the factory default, the manual variant coding routine must be run." Duh. However, I had no idea what code string to enter on the manual variant coding string page... I began to wonder if I had "bricked my ride"...
But after some more exploring, I saw the "restore ECU config" at the bottom of the screen, and realized I could go to TechAuthority, and for a $20-for-24-hour "subscription," reload the default settings into my ECM. Did that, and I'm back to the 82mph limit.
Lesson learned? Read the fine print!
Rock
PS - Jon, the last sentence in that first screenshot above would seem to reinforce your comment about "can't exceed the factory setting." Seems to imply that if you bought a used Sprinter that was originally ordered/delivered with a fleet setting of, say, 65mph, there'd be pretty much nothing you could do to increase it.