I just got my A/C repaired. I know that during the process the battery (or maybe both batteries) were disconnected. I found out because the Guardian GPS app alerted me of a "power disconnection of the unit". The rarity in question is that when I drove off the dealer and put a bit of gas, suddenly the GOM gave me a new estimate of 485 miles on HV mode! Curiously, the EV estimated range wasn't affected at all, and after charging at home it kept giving me the very low estimates I suspect are due to the leaky AC compressor pulling too much juice when attempting to get to the expected temperature. Has anyone seen this?
Early on, some vehicles displayed an optimistic HV range estimate. It may have been limited to the 2018 MY and I believe it was corrected with a software update. Since you recently filled the tank, it could just be an anomaly. Try burning through the fuel and see if it reverts to the norm on the next fill up.
It went down to 380 with the second filling (in the middle of a 500 mile trip). Then 326 in the next. Will see with the next one. BTW, the 'average fuel consumption' read from the ODBII app is wrong. It reads as 25 MPG, while dividing the miles driven by the gallons used (by data from the same ODBII reader) gives me 42MPG, which if I don't recall bad is the official mileage of this car. But this is a subject of another thread, I think.
The claimed fuel economy numbers are 40/44/42, for highway, city and combined, respectively. On long trips we’ve seen 36mpg when driving ~80mph and mid-40’s when driving 60-65mph. There always a chance for error if any EV range has been used and those miles aren’t removed from the miles/gas formula.
The only problem is that the car, even when in HV mode, will use some battery from time to time. You don't ever really know how much and what amount is restored. I'm sure that the EPA test protocol doesn't include trying to figure out how much battery was involved in the calculation. It just estimates how far the car will go using a gallon of gas regardless of the gas/battery usage. So, it's entirely possible that the stat showing up in the OBD II app is correct. Could be that fewer of the total miles used a gallon of gas than thought and the app is dialed in on only the gas part. The Honda folks undoubtedly programmed the system to show miles per gallon based on whatever unknown combination of gas/battery is actually being used, not based strictly on how much gas is involved. Since there is no way to disconnect the battery system so that gas mileage is calculated only on gas propulsion, there's no way to really know.
