Poor fuel economy

I'm the same driver, using the same mild hypermiling techniques but fuel economy is definitely worse in the 2013 PIP that replaced my 100% recycled 2012. What could be the cause???? I've got the grill blocked just like the 2012, I just put on new Bridgestone EP422+ tires and have them inflated to 51 PSI(sidewall limit). I removed the silly plastic rain gutters the previous owner had installed, what a job getting all the foam tape off without scratching the black paint. I've changed the oil, which I suspect was cheap non- synthetic & too thick, I've replaced the engine and cabin air filters which were really filthy. What's left? Ev range both estimated and actual both seem slightly better in the 2013 ( it now has 2910 total EV miles total & as received a total of 603 KW of charge). Torque reports ZERO total misfires, so it's not likely bad plugs. Since EV range is good it's not something like dragging brakes or a bad wheel bearing. What could cause what I estimate is a 5+ mpg shortfall?

 

37000 miles on 2013, old car had 38,000 on it. I have data and memory of old car in similar weather. I'm estimating mileage with the MFD trip odometer checked by actual miles and fill ups. On both cars MFD is about 5% optimistic. Old car had OE Bridgestone EP20's inflated to 50 PSI, new one has new EP 422's inflated to 51 PSI. I added a display of "volumetric" efficiency to my tablet running "Torque" and saw interesting results this morning as I drove about 50 miles each way to get a tankfull of "pure" gas (no ethanol) the efficiency goes up under higher load to about 55% but under light load its in the upper 30 % range. I'm thinking there is a vacuum line off or broken somewhere and will look carefully at them.

 

Congraturations Mendle!
I just jacked up the left rear & lo & behold the brakes are dragging quite noticably, disk is worn further disassembly in process.
Dam this car sure wasn't driven by a typical Prius driver! all 4 rotors are worn severely all pads are nearly gone! all disks are severely pitted as well so I'm replacing the lot. I rarely use the brakes at all regen is usually sufficient.

 

Mendel, thank you for the attachment! All 4 rotors were worn well beyond allowable limits, both sides inner rear pads worn unevenly indicating improper assembly in the past. After replacing all pads and rotors rear wheels spin MUCH more freely. I did NOT diss-assemble any of the cylinders but did grease the caliper slide pins. I did position the rear pistons correctly with the notch over the "pin" on the inner pad. I redid the spin test after pumping the pedal and seeing that the brakes really work, they do! Even did a short test drive all EV of course and redid spin test. there is some drag but very much less than before. A decent spin will coast about 2 full revolutions.I really have a hard time explaining the wear, possibly used as a mail delivery vehicle with many low speed stops. Any way it's fixed and hopefully that is the end of my frustrating low fuel economy.. BTW it's 28 deg f in my garage and the HSI predicts 17.4 miles of EV range, more than I ever saw on the 2012.

 

Thanks to Toyota customer care, I found out that my car was originally sold in Vermont & they even gave me the selling dealer's phone #. Which I called. I had a long conversation with the dealer's service manager who told me that the brake wear was quite normal in that area due to lots of salt use on the roads, however, he was surprised that I had found the "pins" free and lubricated. The dealership last saw the car when it had 25,000 miles on it yet Toyota customer care had recorded service at 30,000 and 35,000 with the oil change at 30,000 done with non-synthetic (petroleum) oil. Toyota customer care suggested that I have a dealer do a "fuel consumption test" to see if the ICE is sick or not ( according to Toyota customer care, all dealers are equipped and trained to do this test).

 

• Well I did a reasonably long trip with the new brakes, tires @51PSI and grill block. Roads were wet in lite rain temperatures in mid 40f. Reset trip b after warm up and logged 190 miles round trip, avg speed 49 MPH, with a displayed fuel economy of 50 MPG. This is a trip I've made many times in the 2012 and under very similar conditions displayed 60-65 mpg. I simply don't need a dealer fuel consumption test! I have enough data to assert that this 2013 is operating the ICE differently that the 2012. WHY? Is there a bad sensor? Is the ECU program different? Is there premature wear of valves, cam, cylinders etc.? What diagnostics are available to pinpoint the PROBLEM?

 

There are no trouble codes according to "Torque". Do you mean the 12 volt battery?

 

OK, looking at the 12 volt battery meant I had to get a 9 volt battery for my DVM. So with a fully charged PIP I drove to the nearby Dollar General, a round trip of 4.2 miles. Back home I parked in the garage and pulled the panels to get to the 12 volt battery. It reads 12.4 volts and is slowly dropping, like it had just been charged. About 15 minutes later I recheck it and it reads 12.2 volts so I plug the car in to charge. The 12 volt battery now reads 13.3 and is slowly rising. About an hour later the car is fully charged and the 12 volt battery reads 12.52 and it's voltage is falling. The garage temperature is 50 f. Another 1/2 hour and it's 12.38 and voltage is still falling slowly. I think it's time to replace the 12 volt battery! What do you think of these , in parallel, as a replacement? https://www.aliexpress.com/item/scooter-battery-e-bike-20ah-small-rechargeable-lifepo4-battery-1