As the weather has gotten colder, Torque has become less accurate. In the summer, it was generally within 1%, and I could trust the distance remaining to within 12km (although I never let it get that close). Now as it gets colder and colder, Torque is producing ever more optimistic fuel consumption figures (i.e. lower L/100km or higher MPG).

My questions related to this are:

1) Which vehicle profile parameters can I adjust to compensate for this? I know that the “fudge factor” (I forget at the moment what it’s actually called) has no effect in Enhanced MPG mode, but do any of the others?

2) More specifically, will setting the volumetric efficiency affect fuel consumption calculations? If so, in which direction. I tried decreasing the VE, and it seemed to make Torque even more optimistic, although this could be a coincidence as the weather got even colder at the same time.

It’s a stock 2001 Saturn SL1 with Saturn’s 1.9L SOHC engine. No custom anything.

One thing that did change is the O2 sensor. I was getting an intermittent SEL regarding a slow O2 sensor (P1033 was the code), and recently had it replaced. Torque was more accurate before the replacement than after. Maybe _that_ was the cause of the change?