Not sure if you were referring to regular Prius, that's the one that has an EV button. The Prius Prime (which is a PHEV for those who don't know) has two buttons, EV/HV and EV Auto Prime defaults to EV mode when you start out, which is indicated on the display To switch to HV you press the HV/EV button. The EV Mode indicator goes away. If you want to go back to EV you press the HV/EV button again and the EV Mode indicator returns. In most cases ICE apparently does not come on in EV Mode, it does sometimes and people complain but I get the feeling it is harder to get ICE to come on in the Prime than Clarity. Although personally I find it takes effort for me to get ICE to come on even in Normal mode in Clarity, but I guess I'm just a lightfoot. If you want additional power in the Prime you press the EV Auto button and the EV Auto indicator comes on This is supposed to make ICE come on during harder acceleration. Although many people say that even in EV Auto they don't notice much difference. This is what the Prime manual says about EV Auto. And yes the grammar error is in the manual, this is a screenshot:
Not sure if it's quite sticky-worthy like insightman's but thanks. Between you, me and insightman we have certainly given the new members plenty of reading material on this topic
Interestingly, the Insight does have an EV button, but the car can travel in EV Mode for only a mile or so. Honda's i-MMD hybrids have 3 underlying modes which are used to provide the user-selectable modes: EV drive (battery power only), Hybrid drive (battery and engine-generated electricity), and Engine drive (engine connected through a clutch to the gears that drive the wheels--battery power also used).
Insight and Prius both have EV buttons, Clarity of course has an HV button. I think the reason is because Insight and Prius default to HV mode on startup, so they have an EV button, whereas Clarity defaults to EV mode on startup, so it has an HV button. The onscreen indicators follow the same pattern, Insight and Prius have EV Mode indicators, the absence of which indicates that you are in the default HV mode, whereas Clarity has an HV indicator, the absence of which indicates that you are in the default EV Mode. With the exception that if your EV range is 0 then you are in HV Mode even though the HV indicator does not appear on the display. In my lengthy dissertation in post #36, which understandably not everyone will want to read all of it so I will summarize it here, I compared the Insight and Prius EV/HV Modes to Clarity to make a case for my opinion that EV Mode and HV Mode are valid terms for Clarity since the operations are nearly identical among the three cars. As well as to validate the use of the EV indicator on the Clarity display, which some have complained about, however I pointed out that the EV indicator on Clarity works exactly the same as Insight and Prius. The Clarity manual doesn't use the term "Mode" for EV or HV, which is understandable since it already uses that term for the three driving modes Eco, Normal and Sport and they probably felt it might be confusing to also use that term for the operating modes. Unlike the Insight manual which specifically refers to them as EV Mode and HV Mode. The Clarity manual uses terminology that implies that HV is a mode, without actually using that word. "use the HV button to switch the vehicle to HV" "To enable HV, press the HV button " "Comes on when the vehicle is in HV" "Use the HV button to select HV" However as proof that it is considered a mode there is in fact a graphic in the manual on page 89 that uses this term: Likewise the term EV mode is not used, but it is implied in diagrams and statements that when not in HV Mode then you are in EV Mode "Any time the HV button is pressed while in HV or HV Charge, the system returns to EV operation" My premise in post #36 is that the EV and HV modes in the Insight, Prius and Clarity work in strikingly similar ways, the main differences is in scale. In EV Mode the level of speed and acceleration that automatically causes a switch to HV Mode is much lower in Prius and Insight than in Clarity. Also the EV range of Prius and Insight is much lower. Of course the power and range difference is so great that it causes us to sometimes think of Clarity as a BEV that happens to have a gas engine, but as I detail in my thesis the actual operation is much more like a hybrid, even if the electric motor is often being used for long periods of time. There are of course other modes like HV Charge and Direct Drive, but in a sense these are really subsets of HV Mode. Even though HV Charge is an operating mode, it is pretty much identical to HV Mode other than having a different set point for maintaining battery charge. Direct Drive meanwhile is a propulsion mode within the HV operating mode. The EV indicator on the display causes some confusion because it is actually referring to EV propulsion mode, not EV operating mode. EV propulsion mode is used in both EV operating mode and HV operating mode. Although confusing to some, it is consistent with how Insight and Prius use this indication. I also pointed out that while the amazing Volt in many ways set the "gold standard" for how EV Mode should operate in many people's opinion, it does not define the term.
