Can bad batteries cause bad mpgs? I'm replacing them tomorrow but I am wondering if it's why I'm getting 12 mpgs

 

thats a good question mine was doing the same i replaced mine with walmart cheap-os for temporary use and my mpgs went to 12 but now that the weather has warmed up my last two reading were 14 then up to 17 i think its just all the idling my pickup does to warm up in winter but thats interesting let me know if good batts make a difference.

 

Will do cowboy!

 

it is possible. but the only way to know is to change them and see if not you may have other problems. worth a shot ive heard of people having this problem and it being the batts maybe it is and youve got a quick fix.