[numpad0]

I wouldn't be sure if that's often the case, most PHEVs are just minor upgrades over existing hybrids. The electric motors on most hybrids, except the Nissan system, tend to only cover zero to city speeds. They need the gas engine connected to handle highway and ramp situations.

[jeffbee]

This is not true. Popular PHEVs like the Prius Prime can go any speed you like on batteries.

[dalyons]

It is true. most are much worse at being EVs than the toyota prime models. Toyotas were the top of the euro data on real world EV-only use. Every other manufacturer ranges from worse to hilariously worse. Toyotas are not over half of sales, so therefore "most" applies.

[jeffbee]

You're making this outlandish claim so it is on you to name any currently or recently-marketed PHEV that can't reach highway speeds in EV mode, and to demonstrate that this constitutes "most" of the market or installed base.

[dalyons]

its been widely reported on.

https://www.theguardian.com/environment/2026/feb/18/plug-in-...

https://electrek.co/2026/02/19/biggest-study-yet-shows-plug-...

https://www.theguardian.com/environment/2025/oct/16/plug-in-...

the link to the underlying most recent fraunhofer study referred to by the first two seems broken sadly, so i cant get the breakdown by manufacturer anymore. But the data on aggregate is clear - on average the PHEVs cars out there today spend very little time on average in pure EV mode. If they did there would be more than ~20% reduction in emissions.

[jeffbee]

You are not addressing the claim that PHEVs can't reach highway speeds on batteries. That is a ridiculous claim, and it is false. You will not be able to name even one PHEV on the market with this limitation, because they do not exist.

[dalyons]

its acceleration that causes them to drop out of EV mode, when the weak EV drives cant produce enough power. Can you accelerate all the way to highway speed in real world driving without it dropping out? for some yes, for many no, from the guardian article:

"Even when the cars were driven in electric mode, the analysis found that levels of pollution were well above official estimates. The researchers said this was because electric motors were not strong enough to operate alone, with their engines burning fossil fuels for almost one-third of the distance travelled in electric mode."

The manufacturers dont list this admittedly complicated crossover, so you cant say whether one does or doesnt from a spec sheet. The aggregate data is clear though.

[loudmax]

Yes, my Prius Prime handles highway speeds perfectly fine on battery. In fact, the acceleration is great in pure EV mode.

It just doesn't have much range: only about 25 miles on my 2018 model. Newer models advertise up to 44 miles on EV.

[jeffbee]

Sure, that's the obvious downside of them. But in the role where they spend ~10h slowly charging overnight from a standard plug, about 25-45 miles is all you'd expect to enjoy in a steady state.

I had a PHEV Honda and I put 20 gallons of fuel in it over 6 years. The system works in the niche for which it was designed.