Other way round. It's underestimating mileage, which is why your fuel mileage looks worse. The stock speedo reads high, and with the Speedo Dr, getting it to read correctly shifts the mileage travelled down the percentage of the speedo error. Typically around 7%, which is significant. If it's off 7 percent in 100 miles and you use 2 gallons of gas (example), your true mileage would be 50 MPG but the error makes it look like you only got 46.5 (93 miles indicated). The average on the 12 o'clock labs website shows a 7.7% error for the stock speedo, but that's an average. Some seem to do better, some seem to do worse.
On mine, I have the speedo corrected for the larger rear tire and the gearing, and the speedo is correct. However, it's off a solid 7% on the mileage. Stock it was off a hair over 7% versus GPS speed, so mine was right about typical for error. I just multiply my mileage by 7% when I check fuel mileage now. Uncorrected I was down in the 55-60MPG range (on road and offroad mix). Corrected It's more like 58-64 which is about what I would have expected with the gearing change. If I'm mostly running it offroad, I can get under 50 no problem. I can get the fuel light with the 3.1 gallon tank at about the 90 mile indicated mark. That's about 2.2 gallons as I have about .9 left at the low fuel light.
Home 
Latest images 
