Speedometer reads 10% fast

[richard_sittingbull]

Hello all,
I have a 2007 NRV Dolphin LX on a W24 chassis. It is still under warranty. Workhorse indicates that my chassis came with the 22.5 wheels that are on the MH. So no new tires have been put on. The speedometer reads 70mph when my GPS and my 2008 Honda CRV say I'm going 63 mph. The difference is exactly 10% off. This is also verified by the highway speedometer checks in the 3 states that I just drove through. They say 5 miles have past and my speedometer indicates 5.5 miles.
My problem is that the Workhorse factory dealer says that his instruments are saying all is OK. I have an appointment with him on Monday at 10:00am to go over his findings. Is anyone out there that has had this problem and can enlighten both me and the mechanic? I'd sure appreciate any help that you can provide.

[richard_sittingbull]

Hello all,
I have a 2007 NRV Dolphin LX on a W24 chassis. It is still under warranty. Workhorse indicates that my chassis came with the 22.5 wheels that are on the MH. So no new tires have been put on. The speedometer reads 70mph when my GPS and my 2008 Honda CRV say I'm going 63 mph. The difference is exactly 10% off. This is also verified by the highway speedometer checks in the 3 states that I just drove through. They say 5 miles have past and my speedometer indicates 5.5 miles.
My problem is that the Workhorse factory dealer says that his instruments are saying all is OK. I have an appointment with him on Monday at 10:00am to go over his findings. Is anyone out there that has had this problem and can enlighten both me and the mechanic? I'd sure appreciate any help that you can provide.

[DAN L]

i cannot remember where or when i read this but the basic idea is that your mileage based warranty would expire early. i believe in was automotive related. it was considered fraud and there was some kind of compensation awarded the owner.
don't let them get away with this.
have you considered a scan guage 2? i just bought one but haven't installed it yet. it may be some help in troubleshooting the cause of the erroneous readings. i am thinking that it might make some kind of a record that would be readable later?
i got my scan guage2 from mileage pros for $155 delivered.

[JonBrazel]

There is a parameter inside the ECM which can be calibrated to correct speedometer error, not something that most Workhorse dealers can fix. We have the capabilities to calibrate the speedometers and workhorse actually sends us quite a few ECM's to fix for that reason. You may want to contact workhorse and see if they will cover the calibration, or if you want to opt for doing UltraPower at the same time you can send us your ECM and we can calibrate the speedometer at the same time (on your dime).

[richard_sittingbull]

Thanks for your input folks. I am on my way to the Workhorse dealer now to hear his lame excuses that he gave the wife. So far, it is my Magellan is off by 10%, my new car speedometer is off 10%, and he ran it for 1 mile and said it was right on, which is hard to do when were talking the difference between 1.0 and 1.1 miles.
It really is too bad that I just returned from Seattle 3 weeks ago. If only I would have known that you (Jon Brazel)can do these repairs to the ECM, I would have made the stop.
Hopefully, Workhorse has a record of his conversations so there is a record of it down the road.