[Al Skierkiewicz]

Let us not forget that depending on the encoder used, accuracy enters into the calculations. If your encoder is only able to resolve about 1" of travel by counting at the wheel, you can get really far off before the encoders will try to pull you straight again. Accuracy can be improved by encdoding a shaft further up the reduction chain. The errors are then divided by the reduction ratio (all other things being equal). You may find that there is a constant difference between sides and apply a constant correction to one side as a simple fix. Although the Chalupa does not exhibit differences between forward and reverse, production differences do effect it's loaded speed and no two transmissions are identical so differences in speed (side to side) are a fact of life.