Sudden drop in Mileage

If it remains consistent, I'd suspect some kind of mechanical damage creating drag which eats up fuel. A dragging brake pad perhaps? Maybe someone didn't finish the repair right and power is bleeding out forcing the ICE to kick in more to recover power for the battery. A simple frayed wire on standard ICE vehicles have been the cause of many a problem with dying batteries or equipment failures, so why not the same for a Prius?

 

how many tanks have you calculated since the repair?

 

Was it a Toyota shop or independent shop? With Toyota, they could "investigate" and repair their cock up under the guise of it being a warranty issue. An independent shop would be more problematic.

 

they messed with something, that's for sure. how is your 12 volt battery? tyre pressures?

 

Well, it's clear it's involving the mechanic/shop. Get someone higher up in Toyota involved if the shop won't figure out what they did wrong at THEIR expense.

 

Are you interested in learning how to investigate and diagnose the problem IF it returns?

It will require some instrumentation, a miniVCI with a laptop running Windows XP would be the starting point. This can give real data to try and understand what is going on.

What does this car typically do each day (i.e., taxi, delivery service, commuting)?

Bob Wilson

 

I'm not sure what they do in the recall, but software can load buggy. When in doubt, reboot? I doubt the Prius software truly "shuts down" when you turn the car off, and a "hard restart" is done by a mechanic.

 

• "reset" - disconnect the ground wire for 2-3 minutes to let the caps discharge

By doing a power-on reset, the stored engine and vehicle metrics are cleared and any changed metrics like the 'backup beep' are cleared to their default state. It takes the car a few trips to relearn the fuel trim metrics and then things return to normal.

Let me suggest a warm-up effect test for the first trip of the day:

• put car in "READY" and hit "EV" to inhibit starting the engine
• clear a trip meter
• turn off "EV" and let engine run until it auto-stops, ~60-80 seconds
• drive normally to work
• record trip meter data . . . do this 3-5 times

What this does is warm-up the catalytic converter and coolant enough to put the engine and car in the most fuel-efficient mode while burning the least amount of fuel. Then during the rest of the trip, the car will burn the least amount of gas.

Now there is an advanced technique but a little tricky. Start the car, fasten seatbelt and adjust radio and mirrors. Then for the first minute, shift the car into "N" to take all load off the engine when you can and take the lowest speed route possible. But this technique takes practice and may be too distracting.

GOOD LUCK!
Bob Wilson

 

i've never seen it, are you at high altitudes and heat?