Yesterday, I noticed, while I drove home (1-3 mile commute), that the mpg numbers were jumping from 99.9 to 48.9 to 89.9 and so on. This morning, the reading went back to normal. My question is, should I be concern about fluctuating of MPG numbers or is this normal? It is the first time it's happen. I have a 2006, package 8. Also, I was in ACC mode for 18 minutes, before I turn the engine on. Could this have an impact on the wacky mpg showing. I drove off after three minutes of starting the engine. Should I be worried? Thanks!
That's normal. As the car switches the ways it's managing power and balancing that with the demand for power the efficiency will change, often quite dramatically.
