How much Gas-only range should I expect from a 2018 PHEV full tank?

A minute or two. I’ve only had it happen a few times, where EV range expired just a few blocks from home. The engine ran for ~1/2 mile at 30mph, about a minute, and then for another 30-60 seconds in the driveway. Of course, if the engine comes on more than a few miles from a destination, it will have gone through a warm up period prior to arriving.

A similar situation occurs when activating HV Charge. In my experience, it takes 3-5 minutes/miles at freeway speeds for the engine to warm up and begin charging.

 

Interesting. I usually only use HV Charge after taking EV miles to zero in order to see how many EV miles I can eke out of a full battery. I assumed the EV miles stayed on zero for several minutes because of designed-in hysteresis, where Honda didn’t want to display EV miles until they reached a certain threshold. Next time I’ll bring up the “Power Flow” screen to see if that’s what’s actually happening, or if your speculation holds. Though a brief warmup never hurts, modern car engines are quite ready to produce ample power on startup, so it’s hard for me to see why 3-5 minutes warmup would be necessary before beginning to charge.

 

I think you are both correct. Watching the RPM on warmup, it stays at 1500 during warmup (a little over a minute). Then, the battery SOC starts to rise, but the EV range does not change until it has reached about 2 miles of range (hysteresis).

 

I’ve used HV Charge about 6-8 times. Starting, in a few cases, with a depleted battery and a few others, with some charge remaining. Typically, just single digits as displayed on the EV range screen. Similar results, either way, using my seat of the pants methodology. In the cases where there was some remaining range, that range decreased ~3-5 miles while traveling ~3-5 miles after initiating HV Charge. Once the range started increasing, it did so in increments of .3 miles.

By comparison, when initiating HV, I have not noticed a drop in range as significant as when initiating HV Charge. There seems to be something going on that takes a few minutes before significant charging begins. Perhaps an engine warm up, an assessment of the battery and a low initial charge rate?

When initiating HV with 0 EV range, the range does indeed, pop up to ~2 miles after several minutes. For all I know, it could be dipping down to -2 miles before rebounding, but the display does not show negative numbers.

The power flow graphic will show electrons flowing from the generator to the battery but it will not tells us the quantity of electrons.