How Usable Is The EV Mode in A Regular Prius?

EV mode requires an already sufficient charge to the battery even in circumstances 1, 2 and 4.

I find that the EV mode may be useful to hold that mode slightly longer when pulling away from a light.

 

Turn off the heat.

 

Given the alternative, it seems like a useful trait.

 

More info needed.
Are 1-4 above during the cold months of the Year or mid summer in S CA ?
Is the climate control system on (heating battery, cooling battery, cooling/heating passenger compartment of vehicle) ?

 

The car doesn't know where you're going. If you're planning a hill descent, make sure your battery is low enough to store the energy you are likely to regenerate.

If the charge is too high, there's nowhere to store that electricity and the car needs to be slowed some other way.

Auto-starting the gas engine and using it for braking is an excellent way to give the driver seamless control in that situation.

 

I mostly use it in your #4 scenario, when the car is warm (ie: return leg of a trip, car is sitting in the sun) and I'm starting a drive in a parking lot. More often than not it works just fine, and long enough for me to get out of the parking lot and start accelerating into traffic. Or if I'm on a busy road stopped at a light and I know it will be slow going when the light turns green.

But my expectations are low - at best you'll get a half mile out of it, maybe a bit more in perfect conditions, and in many conditions like you mention, it just won't turn on.

 

I found one side-benefit of block heater use: a couple of hours plugged in and you’re pretty much guaranteed EV, even for otherwise stone-cold engine. Makes EV actually useful, for stuff like garage-to-driveway maneuvers, say for washing. Kicks off around 15 kmh though. You do have about 15 seconds of EV, always, which is marginally useful if you’re fast. Also gives you time to request EV, and if denied shut down.

 

I don't mess with the EV mode switch, but I do extend it's operation by slowly decelerating on cruise control. Seen it at 75 MPH on downhill parts of I64 going west of my home where the hills get slightly steeper. Going to pickleball on stretches of that 9.3 mile drive with speeds of 45 and greater, I'll play with gradual deceleration to maintain EV mode, especially at the end of that drive so I can utilize the cold engine start hours later when I return home. The last mile to the house I am all EV which helps average mileage greatly. Lower average speeds and stop and go traffic is where it shines, but I generally avoid stop and go traffic, preferring alternatives to the crawl. One time got stuck for two hours between two exits on 64, 4 miles apart, in my Echo and actually got out and pushed the car versus crawling at 2 MPH in a manual transmission.

 

"Cold" will mean different things to different people. In the great lakes region cold can mean 0 fahrenheit. In that kind of weather, my engine turns on almost as soon as the start button is pushed. It isn't a state of charge issue, just that the engine is isn't near a reasonable operating temp.

I look for signs of water accumulation from the oil never getting hot enough, but I haven't seen anything yet.

 

Toyota gave the gen1 EV mode for minor things.

• To have the engine off when getting or leaving home so as to not disturb the neighbors with engine noise.
• For shifting the car's parking place to get things out of the garage.

The list of reasons in the manual for why EV mode wouldn't engage was longer than what they pictured it used for. Avoiding customer confusion and dissatisfaction is likely why the early US Prii didn't get EV mode.

Had the hack for EV mode on my gen2, so know you had to be quick to engage it on car start up to prevent the engine from starting. Creeping at <25mph would yield about a mile of EV range. Newer versions got higher EV speeds, but the battery capacity didn't increase. This makes uses on the road limited, and it is easy to overuse EV mode to the point of hurting fuel economy.

Engine spinning doesn't mean gas is being burned.

 

I guess if the engine continues running after having been spun for braking effect, and doesn't stop until reaching an operating temperature, then gas does get burned for that part.

 

I mean at ambient temperature. For the purpose of this discussion, summer or winter I can’t recall EV ever being available, with an ambient temperature engine. This is with my gen 3 at least; may be different with gen 5.

 

A regular Prius of this generation will do that. It was high 50s this morning. I was able to pull out of the garage space, down the drive and several houses down the street. By the time I hit 20mph, the engine turned on.

If it's well below freezing, the engine is on almost immediately.

It strikes me as a gimmick, and I just wanted to see how long it would go. I doubt it saves much and delays the engine warm up.

 

It'll go through the warm up stage if that is the first time the engine started on the trip. Once that's done, you can't assume engine spinning means it is running.

It is a gimmick. It was given to the first Prius for times like 'I need the lawnmower, but the car is in the way'. On the road, it is easy to use too much, and then the car needlessly burns gas getting the battery charge level back to what it is happy with.

 

I understand that some would like EV only mode to be more frequent. I wonder if the car would be better by making it less frequent. If I'm just noodling around suburbia, I might find that the trip shows as 60% to 70% EV. I spent an hour on two lane roads on the way back from my girl's school and it showed as 80% EV.

If someone started my car for 30 seconds every few minutes while it sat in the driveway, I think I'd want to punch him. It can't be any easier on an engine to be started to be under immediate load to also serve as a generator.

I don't know anything specific about this engine. Maybe it was adapted to be turned on and off all the time with no undue wear.

The planetary whatchamacallit can produce some apparently low engine revolutions at speed. I would think that leaving the engine on while the battery dumps enough juice into the electric motors to stay optimally charged and turn low revolutions would also be pretty efficient overall and easier on the engine.

 

I wouldn't put much stock in that EV ratio. Foot off the pedal coasting is likely being counted as 'EV'.

The starting of the engine is far easier on it than in a non-hybrid. A starter might get the engine up 300rpm before firing the spark plugs, with barely anytime for the oil the flow. A full hybrid spins the engine up to near idle rpms before it actually starts. This is less jarring to the engine, and gets oil pressure up before real stress is applied.

The engine is only put under load right on start up in extreme circumstances. The battery and motor still do most of the work after the engine starts.

Gasoline engines are generally at their peak efficiency when operating under about 70% load. The car gets the efficiency it does because the system tries to run the engine at those heavier loads as much as possible, and then turns the engine off when it can't. Running at low rpms for longer results more negative impact to efficiency from pumping loses.

 

It is meant for only moving the car a few feet or a few hundred feet at most without turning on the engine and causing it harm to it due to fuel dilution etc. from short trips etc.

 

If it’s reliably turning on after cold-soak, accept in the coldest depth of winter, that’s a big improvement.