ICE engine at start-up

It warms up the engine and the cat converter to lower emissions. When the engine is warming up, the battery does most of the pulling. From what I read, the engine in warm up is running super rich and timing super retarded and does not put out much power at all.

I have found that if I need to move the car out of the garage to the driveway for something and back, hitting the EV mode will avoid the ICE from firing up and dump fuel for a useless warm up. Assuming the engine is not super cold, and the battery has 4 bars or more.

 

I call it a fuel dump to warm the CAT. If your battery is not too low, I would just drive it. I usually finish warming up by the time I finish crawling in the neighborhood. I would not think it would be wise to go WOT during this initial warm-up. I do not think some light duty driving would hurt, and it would yield better MPG. 25MPG is still better than 0MPG.

 

Letting your prius just sit in a driveway buring gas would lower your mpg. I'm sure of that. You can be easy on the car untill it warms up though.

 

Under federal consumer law the ice must come on within 20 seconds to recharge the battery to ensure that the battery life be prolong for the warranty. The 100k battery warranty is by federal law due to high cost of replacement for consumers. 14 states have adopted the Calif. law or green law which mandates that the manufacture guarantees the life of the battery for 150 k. Massachusetts is one state that adopted the Green Law and I am so glad...had to get a new battery at 135 k. Dealer was going to charge me $3600. plus for a new battery until I informed them of the 150 k warranty!! Talk to a Prius friend of mine from Canada and he loves it that he can leave early in the morning to work without waking the family cause his ice does not come on unless battery recharge is needed.

 

trade it in on a pip! you can back out of the garage, go down the street and pick the time and place you want the ice to start, if at all. it is so sweet! the one thing that always drove me crazy with my former two pri was, you'd put it in reverse, just be backing out and wham! on comes the ice.

 

Also keep in mind if your climate contol is calling for heat or defrost ypu ice will start to meet that request.

 

Our Prius II starts up within 20 seconds every time when the ICE hasn't been run for several hours, but I can't imagine anyone who would be awaken by the sound of that throbbing 1800 cc engine, unless they were sleeping in the back seat.

 

I thought the ICE must start up to warm the ICE and the catalytic converter so it will meet the emission standerds.

 

Can you avoid the ICE startup by use of the block heater available at the PC store? And the F/U question : is it worth the bother ?

 

Those are great questions, I'd also like to know those answers.

 

i don't think a block heater will prevent start up, but it does reduce warm up time and cabin heat. is it worth it? kind of a subjective question. it will save a bit of gas in favor of electricity from the wall. keep in mind, a few miles down the road, all things are equal again. in really harsh climates, they can help a car start and reduce wear. but the new synthetic oils also do a good job of that.

 

My morning protocol, leaving the house for work:

• get everything in cabin ready
• press brake and POWER to READY
• hit "EV" in case it works (does not work when cold or battery low)
• exit driveway
• modest acceleration to 25 mph (neighborhood speed) and shift to "N"
  • This minimizes the fuel burn to idle rate, the same rate seen if in "N" and parking-brake held on the driveway.
  • Continue to cycle between "D" and "N" in neighborhood.
• reach first traffic light, usually red, use "D" to stop
• test "D" for a couple of seconds, on and off until ICE auto-stop or light changes
  • ICE auto-stop while braked to a stop signals the catalytic converter is working
• drive next mile or so with traffic on slow-side of traffic speed as coolant warms up while ICE coolant reaches 60-70C to reach normal hybrid driving mode

There are two warm-up thresholds: catalytic converter light-off and ICE coolant warm-up. Catalytic converter light-off is known when the ICE auto-stops when the car is stopped. Hybrid mode occurs when the coolant is warm-enough so the ICE can auto-stop when the car is moving.

Bob Wilson

 

Does anyone have "hard Proof" that a block heater would shorten the ICE warm up time? So, when would one want a block heater on a Gen III PRIUS ? We have 2, 2011 Prius II's that are in a attached garage (rarely goes lower than 30 F) in Wisconsin winters. I just wonder if it would be worth it on a Hybrid Cars? Our local dealer here in Madison, WI claims they have sold/installed almost zero block heaters. The problems is I can see the logic in needing one and logic for not. I guess for me the breaking point might be if it shortened ICE "warm up" emissions time. Granted the heat coming on quicker would be nice too. Anyone can share good info on this I would love to know.....Thanks

 

1. Yes - I haven't seen any studies of the ZVW30 but we have a lot of earlier, 1.5L Prius studies showing they are effective. They can reduce the warm-up time by 2-3 minutes.
2. No - the ZVW30 has engine coolant heat exchanger on the exhaust pipe which significantly shortens warm-up time.

Bob Wilson

 

This thread HSD behaviour during S1a & S1b warming stages | PriusChat shows exactly what coolant temp to aim for to get the best bang for the cost of electricity of the block heater. I think the net result (that I take away) is that you want to aim for 28 deg. C coolant temp went you start the car. That reduces the idle run time to the minimum 60 seconds and shortens the total warm-up time.

 

rokibler/ALL,

How many of you run block heaters and do you notice a difference?

Also, I know that the thermal recovery tank, that keeps the coolant warmer longer, works well. But, how long will it keep the coolant warm?, Surely not overnight in Wisconsin winters? I want to know as much as possible BEFORE I purchase block heaters for both cars......

 

First, the engine block heater (EBH) costs $59 here on the web site, and you can do the installation yourself. My daily commute is short, so 5 minutes of warm up time is 25 percent of my morning commute. I never tried to calculate the amount of fuel economy I gained with the EBH. I learned from others on PriusChat that it was worth it. I have an EBH on both the Gen 2 and Gen 3 Prii.

Let me give you an example of how the EBH helps. In the colder weather, when I leave the office, there is a stop light about 100 yards from the office. It's a long light. It may be five minutes. If the outside temp is about freezing, and the coolant temp is about zero C when I start the car, it will idle at the stop light until it becomes 40 C. That can be more than three minutes. You can sit and watch the CONS number drop and drop and drop. In the morning, coming from the house, and starting the car with an outside temp of freezing, the EBH will have pre-heated the coolant to at least 28 C. The idle time in the morning is the minimum of 60 seconds, part of which may be stage 2, allowing me to drive using the ICE and not the battery.

I far as I remember, the Gen 3 does not have a thermal recovery tank.