I have one and have only used it for cargo so far. Hoping to get 5th wheel next yr and hoping it will work with it. The calculation for the truck was right on. Had weighed it already. Added what I estimated to be about 1,000 lbs and it showed a 930 lbs added so I think it was working well. Didn’t have a scale to check that yet but will when we add the 5th wheel. The only problem that I had happen was I left it in the OBD port for some time I came out one morning and the info screen had gone blue. Thought oh know , have to go to dealer and get fixed. Then I was like what have Iv’e done lately and I remembered I have the HaulGauge still in OBD port. So not even thinking that was going to make a ding dong. I turned truck off, removed it and started truck back up and , oh yea , info center back to normal. Sweet. So now after I use the Haul Gauge I do not leave connected anymore. That’s all the experience I have with it so far.