Sudden drop in life-of-vehicle mileage

I'm intrigued why you reset both A and B. Most people would reset just one and have that as their "between fills" reading. And use Trip B for some other reason. I'm thinking that you may have accidentally had ODO instead of one of the others selected.

Or that the TOYOTA got confused - it is a computer on wheels after all. Just hasn't got a CTRL-ALT-DEL feature.

 

I have never reset my B tripmeter; therefore I have lifetime data. I reset the A tripmeter every fill-up. And at the same time I “update” the eco screen.

 

The manuals are online here. It is easier to search pdfs

2017 Toyota Prius Owners Manual and Warranty - Toyota Owners

 

It does only if you leave either A or B alone and never reset. It is said to be fragile, but disconnecting my battery has not reset it.

 

I only reset A when refilling. If say I'm on a day(or 3)'s touring, I'll reset B at the start so I can track how it went over that period of time.

 

Perhaps there's something missing from my psyche, but I can't be bothered. It's all 'history' and can't be affected afterwards.

 

Well, yeah - that's life. Depends on your point of view - whether you're facing forwards or backwards.

Me - I'm heading to bed now - look upwards instead for a new perspective.

 

Like the new digs Alan.

 

My Duesenberg? She's a 1934 - sadly not mine. I couldn't afford the petrol. Plus - I'm about a million dollars short of the asking price:

 

It probably sounds criminal on this forum, but I just drive my 2017 like it is a ....... car. With every car owned, I have always reset the mileage with each fill up to have a decent picture of my gas mileage. It is wonderful that some techies want to analyze every ying and yang of their Prii, and it does produce some interesting reading. And helps the rest of us non-techies to better understand what the heck fuzzy is happening with our dear (both expensive and close to our heart) ......cars. There are so many factors that significantly affect gas mileage that we will never find the perfect key to the relationship between how much fuel we feed our cars and how far they go. Besides road speed, it seems to me that wind speed and direction, temperature, condition of the pavement, passenger weight, and the amount of air in the tires are some of the biggies. (As long as my car averages 50 MPH or so, I am thrilled.) Y'all are welcome to discuss this til the cows come home.

 

Right...

 

I joined this forum to research this specific topic. My 2016 Toyota Prius Eco Two has 35500 miles on it as shown on the Odometer reading. Up until this, my ODO mpg was right around 58 to 59 mpg. All of a sudden, sometime around 35000 miles, the odometer started giving me a mileage between 52 to 53 mpg. I have always driven the car in PWR mode. The sudden change in that reading has me worried that I have a gas leak and/or wondering if something has malfunctioned electronically.

 

Tire pressure? Sticking brakes?

 

New tires? Oil change?

 

Welcome to Prius Chat @OV7 . There are two suggestions for you, but was your route identical, or was the a significant wind/temperature variation. Even driving on wet roads will pull your mpg down. B hour you can find a simple answer without resorting to the dealer's shop.

 

Our fuel economy seems stubbornly high this spring, not sure why. Seems like it's hitting the wall around 4.9 (litres per 100 km) vs 4.4~4.5 in previous years.

Possible culprits:

1. Lots of shorter trips, while long enough to be fully warmed up and efficient, are leading to deposits somewhere, maybe possible injector clogging, something like that.

2. Something obscure, like Oxygen sensor, or spark plugs. Only 75K kms though.

3. Poor gas??

4. Engine air filter? It's never been changed, but I've read it's not a factor in modern computer controlled and fuel injected engines, AND it looks clean enough to eat off, still.

Seems like whatever it is, it might be time related, as Vehicle ages. Tire pressures are fine, a bit over spec as usual, and hybrid battery seems to be behaving normally. I checked voltage by block and they're all apparently between 16.42 and 16.48 ish.

 

Could be a human thing (no, I don't mean putting on weight) - but our driving isn't consistent, even though we think it is.

My first tank of fuel is always my best - I figure I'm getting used to the car, I'm also trying hard to find out how good it goes, economy wise. As we get used to the car, economy may not be uppermost in our minds.

The other thing I notice is my economy improves the closer to empty I get - particularly if the tank average (TRIP A for me) isn't as good as I hoped. Psychological incentive.