They are all off, even my previous Liberty was off. Run bigger size tires to compensate next time you change tires. Based on my calculations you would need to be around 30.5'' Diameter to read close to accurate. Stock is 29.5'' Diameter.
2007 WK CRD QDII, GDE HOT tune. 275/55/18'' on Sahara's, SRT8 suspension.
2000 Jetta TDI (hers)
2006 Liberty CRD (sold)
3 VW TDI's (sold)