Finally a decent explanation of what you're saying with the math behind it (besides just yelling F=MA, F=MA!). I think this discussion is very good and beneficial, as it encompasses quite a few things. No need to hurtle insults, I grasp math and physics just fine. I'll agree that this is a way to look at it, but my viewpoint works just as well. Either weight can be unchanged (and inertia changes) thus acceleration changes because of a different amount of power available at the wheels, or power at the wheels doesn't change but effective mass does, thus does acceleration. In the end, both cases accomplish similar tasks. I prefer the "effective mass" method since it nicely shows where and when inertia is most prominent and, in some situations, can be a better descriptor for what's going on. Other times, the "more available power" method can describe a situation more clearly. It depends on what one is looking for. Sometimes, it can be tough to see someone else's viewpoint when you think only you're "right". Sometimes, no one is really "right" but both are seeing things from a different prespective that "works" for them. This is not a jab at you, Steve, but rather a commentary about this discussion.