To all that are running an electronic speedometer. Question 1, Have you noticed a discrepancy from what your speed reading as compared to what the odometer actually reads? Question 2, Are you using a sender at trans or a GPS receiver for a signal to your speedometer? Reasons for asking. I cheated by using a GPS receiver with a fixed reading of 8,000 ppm or 16,000 ppm per how it's wired. The speedo in question in a SW Wings and wired for 8,000 ppm. Instruction for speedo does not state anything about how to wire a GPS receiver however SW tech on the phone tells me I can but I'll need to re-calibrate. So I calibrated (with my o.t. 2013 GMC truck as test mule) but to get speed to read correctly I could not drive a complete mile. The magic ticket was to drive only 8/10th's of a mile. But guess what!? For every mile the SW speedo clicked off the mule only traveled 8/10th's of a mile. Not a shocker math wise but this tells me that the odometer is possibly working off a direct circuit from incoming signal. The floor is open to any thoughts.