If you run the lpf speedo hard in a 4wd it may go pop... my mates did.. running 4 lpf's in 2wd down to 7.5 motors.. i think thats within the safe zone for the lpf...excellent speedo.. none have ever missed a beat!
Also.. using the pro in an x6... very punchy and feels much better.. in comparison the lpf feels a tad flat! Value for money and reliability i think the speed passion speedos and motors are hard to beat imo.
hope that helps