10UHCSEL

The Bell Performance link states 2% more energy in the summer blend, just says less mpg's with winter blend.

Might try any of the gas treatments available, whether STP, or Supertech, WM's brand, it may or may not help but these only cost about $2/bottle and usually treat 21 gallons per bottle. I use the Supertech brand in my vehicles during the winter time to offset the winter blend gasoline, and it reportedly cleans the injectors and such. My mpg is usually the same as my summer mpg or a bit better. I've read where winter blend gas knocks the mpg's down 10-20%

How does one determine if you have HF 35 tranny in their Cmax??

I've seen one ground connection in the rear hatch area that is visible when I removed the very 1st layer of cover but was not sure that was an appropriate negative connection to make. Will look some more. Thanks for the advice.

So far I have not been able to find the negative post on the battery itself in the rear hatch area, so will have to look harder I guess. I did find the metal post mentioned in the engine compartment and was able to get a VDM reading using it. I prefer to use quick disconnect type connectors and did not see an easy way to make the connection in the engine compartment. More digging and looking. Thanks for the replies.

1st post, and I've searched several times but unable to find the answer to my question. Got a '13 Cmax SEL back during the summer for the wife, she likes the car alot and is still figuring out the differences with a hybrid and a ICE only car. I want to install a 12v battery charger to the car but cannot quite figure out how to accomplish this seemingly simple task. I have found the + post under the engine hood, but where do you make the negative connection? I don't want to make a wrong connection and fry the wiring, etc. Thanks in advance.