Over priced gauge??? most gauges are overpriced, but I think tis gauge is pretty vital if using different fuels so you at least know the ethanol content of the fuel in the tank and either take it real easy or load a tune to suit. The sensors appear accurate, the problem is Zeotronix changed the sensor that they were using, I appears there is a difference in output between the two types but consistent between sensors of the same style, the newer style appears to show a lower ethanol reading compared to the earlier style sensor which always showed United E85 as between 83-85%