I purchased an off-lease 2015 Prius 4 with 30,000 miles back in 2018. Car was in like-new condition. Still shod with serviceable original tires. Routinely got 50-55mpg for 5yrs. Changed tires to cheapo Chinese ($75/ea vs $185/ea for OEM). Mileage immediately dropped to 45mpg. I get it, softer compound/more rolling resistance, no biggee. Fast forward to present day; car now has 48,500mi and now only gets 35-37mpg. I have had local Toyota “stealership” where I had purchased it perform all recommended services at proper intervals. Any ideas as to what’s going on? Thanks!
I have a 2015 with now 110k miles and still get 52-56 mpg in warm season. Overinflate the tires to about 40 for starters. Next you will hear from all the EGR zealots that will tell you to clean that system which has nothing to do with gas mileage. With that low yearly mileage, possibly your battery has been affected...it likes to be used and not sit around.
tough one if you don't have any trouble lights. sticking brake maybe? dirty air filter? weak 12 volt? i'm assuming the dealer hasn't done anything but the recommended maintenance? are they following the time or mileage recommendations?
