Why does the Ford C-Max have to warm up in order to get good MPG
Test driving a C-Max, it takes 10-15 min for the MPG rating to get out of the
teens and into the 30s. But my Prius gets 35-40mpg right from the get-go. I
only drive 5-10 min to get to work in the first place, so if the good mpg doesn't
happen til later, then I'll stick with a Prius.
7 Answers
It's running in open loop while cold. That means the signals from the 02 sensors are ignored by the ECU until they (the 02 sensors) are heated enough, and that may very well take 10 minutes. Then when the sensors begin to generate a voltage it goes in to closed loop for normal driving. The short 5-10 minute drive to work is just not enough time. Best wishes, your Prius is a better choice for those short start/stop cycles
So, why doesn't the same thing happen in the Prius?
Because it's a hybrid and is set up way different. Even with engine running some or all power is supplied by the electric propulsion system
If your gauge is set up to measure average MPG it takes a few miles of highway driving to average out the poorer mileage you get on city streets and while it is cold. Your Prius is running on battery power for the first couple of miles!
Thanks, Fordnut & Fullofregrets. Shouldn't the Ford CMax run on electric in the first couple of miles, too? Awww, I will probably just get the Prius. Too bad, though, because the CMax is peppier.
Oh, my dumbass didn't know what the C-Max is. I thought it was something completely different. It is available as a plug-in hybrid, or a 141HP 2.0L and combined in tandem with the electric motor puts out an impressive 188HP when working together. It gets 45mpg. And reasonably priced. Sorry for the mis-information, I should have looked it up before spouting. You might want to re-consider... nothing wrong with Prius but from what I have read The C-Max may be superior. http://www.edmunds.com/ford/c-max-hybrid/
Short trips to work, the Cmax Energi is the way to go. My old demo, 7 mile drive to work I made a tank last 2 months.
