Originally Posted by Knightrider03m
Do not use the EVIC as a way to add your gas mileage. The only true way to do it is using the old pen and paper way. The EVIC just gives a very loose estimate.
Two things to give pause with EVIC numbers. First is the usual, plain old accuracy. But second, what are the reset parameters?
Our former '94 Limited's EVIC just kept computing until it was manually reset. If you hadn't reset it for 5k miles and went on a 1k trip, it would give mpg for the past 6k miles. Watch it long enough and this became apparent.
Not so with the WK2 EVIC, as is evident from the variance pattern of its readout. At some undefined point it recalculates, recombines or whatever, so in reality you can't tell a whole lot about what its numbers mean. The readout just yo-yos up and down with no apparent logic, although of course if we could hack into the code we could figure out what's going on.
Perhaps this should a Car Talk puzzler question?