2007 model Prius with 74k miles. I was getting 45.6 mpg on the trip computer. MPG dropped a couple of tenths pretty quickly. Got fuel and put in some Techron fuel treatment. Checked 12v battery, was a bit on the weak side, so I replaced it with an Optima Yellow Top today. Checked voltage and everything was good. While I had the battery out I let the car sit for 10 minutes to reset the ecu. Now after 40 miles I'm getting 35 mpg on the trip computer, and the ICE kicks on any time I press the accelerator pedal, even if I'm going down hill from a stop. There is no difference in driving style, tire pressures (40 front, 39 rear), I bought the fuel at a place I normally get fuel (Kroger, I'm going to stop buying their fuel). Is there some kind of reinitializing procedure I didn't do after the ecu reset? Is it bad fuel? Does it just take a while for the computer to re-learn? Thanks for any help!
Not sure why your MPG is low, What was your AC set on? if its really hot and you have it on like 68, the engine stays on much more. You also might want to check and see how many volts your new battery has, just in case. Really wish i had a good idea or answer for you, But right now i'd say "reset your average MPG and just drive" Check back in with any news, or results. Best of luck!
