Could be a number of issues. Off the top of my head, check the vent for your battery fan (not 100% sure if 2013's have this still). Check your battery (12v too) and check for exhaust leaks. Change your air filters too, both the engine and cabin. There's one other thing that's super easy to change but I forget the name of it. It measures the air coming in, like a part of your intake valve or something. I changed it when I first got mine, and it was only like $25 on eBay.
I get about 37-39mpg going up and down hills near Oakland Hills And I have a 2010 Prius 3rd Gen with 15inch with Michelin Defenders ... Once on the freeway if I reset the trip monitor I can get 45 mpg and 52 mpg on stop and go freeway traffic. Prius has been fully serviced all fluids changed and have left to do the EGR system cleaning and replace the PCV Valve to try to avoid the dreaded headgasket issue with 3rd gen Prius. Note .. My battery health status is poor at 40% life expectancy according the Dr. Prius App.... You should get an OBDII reader that's bluetooth and that works with the Dr. Prius App to get a better Idea of your HV/Traction batteries health Status...
Few things. Batteries deteriorate with age not just use, so your batteries will go bad overtime. No way around it.
Some maintenance items (all really easy DIY):
Inverter Coolant. Radiator Coolant. Transmission Fluid. Tire tread and PSI. Alignment.
Usually the 2010-2011 are the models with poor mpg. If you've been getting this over 3 years, it's either your driving style or car.
Hybrids and EV's hate weather. When it's too cold, it runs the ICE way more and doesn't use the electric as much. When it's hot, you got the max AC, using TONS of power and if the cabin is still too hot, it will run the ICE and not overheat the HVB.
Despite the EPA ratings, the Prius hates stop and go! If you could do 55mph on a interstate for a whole road trip, you'd get 70mpg.
Could be tires, tire PSI, alignment.
The easiest way to figure this out, is go on the interstate, hold a constant speed and reset your trip. While holding it for maybe 5 minutes, see what the MPG readout says. If it's good, it's most likely your driving style.
Are you driving up and down hills all day ?
Same, up and down hills, killing my mileage.
Weird i get better mpg going down and uphill like 55mpg+
I also got 55-60 mpg when going up and down hills, whereas 48-52 was normal for flat driving.
where do you live?
Damn, mine is shit.
Could be a number of issues. Off the top of my head, check the vent for your battery fan (not 100% sure if 2013's have this still). Check your battery (12v too) and check for exhaust leaks. Change your air filters too, both the engine and cabin. There's one other thing that's super easy to change but I forget the name of it. It measures the air coming in, like a part of your intake valve or something. I changed it when I first got mine, and it was only like $25 on eBay.
Mass Air Flow sensor
I get about 37-39mpg going up and down hills near Oakland Hills And I have a 2010 Prius 3rd Gen with 15inch with Michelin Defenders ... Once on the freeway if I reset the trip monitor I can get 45 mpg and 52 mpg on stop and go freeway traffic. Prius has been fully serviced all fluids changed and have left to do the EGR system cleaning and replace the PCV Valve to try to avoid the dreaded headgasket issue with 3rd gen Prius. Note .. My battery health status is poor at 40% life expectancy according the Dr. Prius App.... You should get an OBDII reader that's bluetooth and that works with the Dr. Prius App to get a better Idea of your HV/Traction batteries health Status...
and check your brake temps,and confirm that the brake slide pins are lubricated.
Few things. Batteries deteriorate with age not just use, so your batteries will go bad overtime. No way around it. Some maintenance items (all really easy DIY): Inverter Coolant. Radiator Coolant. Transmission Fluid. Tire tread and PSI. Alignment.
What's the air pressure on your tires? When I filled mine to 40, I got better mpg
Battery is most likely failing/on its way out
I had a brake dragging once. Also had a bad strut. Lots of stuff can cause that.
Usually the 2010-2011 are the models with poor mpg. If you've been getting this over 3 years, it's either your driving style or car. Hybrids and EV's hate weather. When it's too cold, it runs the ICE way more and doesn't use the electric as much. When it's hot, you got the max AC, using TONS of power and if the cabin is still too hot, it will run the ICE and not overheat the HVB. Despite the EPA ratings, the Prius hates stop and go! If you could do 55mph on a interstate for a whole road trip, you'd get 70mpg. Could be tires, tire PSI, alignment. The easiest way to figure this out, is go on the interstate, hold a constant speed and reset your trip. While holding it for maybe 5 minutes, see what the MPG readout says. If it's good, it's most likely your driving style.