Clarity Power and Drive Modes Summary (EV, HV, ECON, SPORT)

As a first time PHEV owner, it took me nearly four weeks to figure out my 2018 Clarity's [HV], [ECON], and [SPORT] buttons. The dealer of course knew nothing. Information in the Owner's Manual is widely scattered (and neglects even to define "HV"). Most ads and reviews on the web have very generalized descriptions. Many forum posts with details focus on specific scenarios. Building an overall picture took a lot of searching and reading.

I wished for a mid-level summary, describing the buttons' effects, combinations, advantages, and indicators all in one place. Eventually my notes started to look like one; then it became a project. The results are below, as an aid to future Clarity PHEV novices. Some of the information comes from replies in this forum and others, so thanks to everyone who contributed.

Suggestions are welcome; hopefully I can update the base note. I would like to keep it concise, perhaps oversimplified for readability, but not incorrect.

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Clarity Power and Drive Modes Summary

This article describes what the Honda Clarity's [HV], [ECON], and [SPORT] buttons do. It is a simplified view of a complex control system. For example, the gas engine may start or stop in situations not mentioned here, depending on battery charge level, ambient temperature, or other factors.

Page numbers refer to the HONDA CLARITY 2018 Plug-In Hybrid Owner's Manual.

Instrument Panel Indicators [p.23]

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Also see [p.122] for a description of the POWER/CHARGE Gauge (curved blue line), which can help you control when the gas engine turns on.mi

EV and HV Power Sources [pp.15-17]

The [HV] button selects whether to run mostly on battery power (the default) or mostly on gas engine power (HV ON). In both cases the "EV" indicator appears when using battery only, and turns off when the engine is running. [p.89] For convenience and symmetry, this article uses "EV" to refer to the default HV OFF, even though the Owner's Manual does not.

EV (Electric Vehicle) [p.15]
Best for local trips and daily charging. Minimizes refueling.
Using Economy Mode with EV facilitates purely electric driving (see below).
> EV is the default setting when the car starts. If the "HV" indicator is on, press the [HV] button to switch to EV.

• Uses primarily the battery when driving.
• Engine adds power when needed (hard acceleration, steep grades, heavy A/C, cold weather, ...).
• Automatically switches to HV when battery charge drops below about 10%.

HV (Hybrid Vehicle) [p.16]
Best for long trips, mostly refueling along the way rather than recharging.
> Press the [HV] button to turn ON the "HV" indicator.

• Uses primarily the gas engine when driving.
• Battery lends power when needed (hard acceleration, steep grades, heavy A/C, ...).
• Engine restores the initial battery charge level when it can, during light driving loads.
• Efficient engine, and direct wheel drive at medium to highway speeds, yield high gas mileage.

HV Charge [p.17]
For recharging the battery while driving (essentially transfers energy from fuel to battery).
> Long press the [HV] button for a few seconds until the "HV" and "CHARGE" indicators turn on.

• Engine powers the vehicle and charges the battery to about 58%.
• Not recommended for slow driving or frequent stops.
• Lets you build up battery power to help with an upcoming long climb.
• Lets you increase space in the fuel tank to maximize the next fill-up.

Drive Modes [pp.11-12]

The [ECON] and [SPORT] buttons select one of three Drive Modes, which are performance tweaks applied to either EV or HV.

Normal Mode
> If the "ECON" or "SPORT" indicator is ON, press its button so that both are OFF. They stay OFF next time the car is started.

Economy Mode [p.388]
Increases energy economy.
> Press the [ECON] button to turn ON the "ECON" indicator. It stays ON next time the car is started.

• EV driving seldom uses the engine for added power, unless the accelerator is pressed past the detent (click). Conservative EV driving can be purely electric.
• The accelerator pedal is less sensitive than normal.
• Reduces climate control. Cabin temperatures fluctuate more. May use the driver's seat heater instead of warm air.

Sport Mode [p.389]
For spirited driving, hills, and curving mountain roads.
> Press the [SPORT] button to turn ON the "SPORT" indicator. It reverts to OFF next time the car is started.

• The engine turns on sooner than normal for added power.
• The accelerator pedal is more sensitive than normal, for quicker response.
• The Deceleration Paddle setting stays on if Cruise Control is off (at maximum it's a bit like "single pedal driving" of other EVs). [pp.32,390-392]

 

Force of habit. I spent my early career as a tech writer, long since retired, so it's hard to resist. But don't worry, there's still the inscrutable POWER/CHARGE Gauge. For now.

 

I think you are right, the wording could be improved. I was thinking of the case where moderate acceleration during heavy A/C use might cause the engine to start earlier, and the case where the Clarity decides to run the engine just to circulate the oil. Wording in the Owner's Manual seems careful not to exclude such possibilities. However, those are not driving loads and seem unlikely for most drivers. For this simplified description I would gloss over them by saying something like "EV does not use the engine for added driving power, unless the accelerator is pressed past the detent".

Wish I could edit the base note, but I don't see a menu entry for that.