Warmup: what a Prius wants...

[wfolta]

Given that the Prius will warm up the engine when it first starts, what is the best usage during that warmup period? (I realize that you want to minimize the warmup time, but given whatever time you have, what's the best thing to do during that time?)

In my experience, when I leave the garage in the morning, it's 0.2 miles to go from my parking space (two floors underground) at about 8-10 MPH to the garage doors, at which point the trip odometer indicates about 16 MPG. On the way home, I start on relatively flat ground, and it seems that 30 MPH is the sweet spot during warmup: slower lowers your mileage because you're simply not moving enough, and higher adds more load onto the warming-up engine and also decreases mileage.

Anyone else have observations about what seems to be the most efficient driving speed/pattern during warmup?

[krousdb]

I have experimented with this on my drive home from work. I use EV to get me out of the parking lot and disengage EV when turning on to the road. At that point I have tried two different approaches. The easy does it approach is light accelleration up to 40 MPH and hold her steady until I am out of stage 1. That method usually relies on MG2 to accelerate the car and results in my SOC dropping to the low 50's before it begins building up again. The second method is to accellerate hard enough to make the ICE do all of the work with little participation from MG2. My SOC stays at about 60%. For me, the latter yields much better results than the former. By the time I make it about 3 miles to get on the interstate I am at 60 MPG at 60% SOC. Using the easy does it approach, I am lucky to be at 50 MPG and my SOC is at 58%. Which approach do yo think I ended up using?

[anne1965]

I believe that what we're seeing here is the emissions vs economy trade-off that was made. With a cold engine and catalytic converter, the Prius uses the electric motor to reduce emissions at the expense of fuel economy.

[a64pilot]

Originally Posted by anne1965

I believe that what we're seeing here is the emissions vs economy trade-off that was made. With a cold engine and catalytic converter, the Prius uses the electric motor to reduce emissions at the expense of fuel economy.

Will you explain? I don't understand what your saying.

[cmalberto]

Ok I will admit my ignorance. Can you point me to what these acronyms mean.
SOC
MG2

60MPG at warmup. I usually get my worst mpg at startup, granted I have only had for 3 days. I am struggling with the best approach on acceleration on to highway(65), mid-speed roads(45) and then of course in-town(30). Do you just get there and level off, hence the lower MPG upfront or do you become a nuicance and put, put to final operating speed staying in the ECO zone the whole way. I tried the ECO method today as there was no one behind me. It took a long ways to get to operating speeds of 45 and above.

Sorry for the the newbie mentality. I hope this may address some of newness questions out there.

--Mickey

[Philosophe]

Originally Posted by cmalberto

Ok I will admit my ignorance. Can you point me to what these acronyms mean.
SOC
MG2

SOC = State of charge, of the main traction battery
MG2 = Motor/generator #2.

The Hybrid Synergy Drive (HSD) combines an engine and two electric motors/generators (MG1 and MG2) into a planetary gear (the power split device). Engine is the planets. MG1 (the sun gear) mostly act as a generator to generate current. MG2 (ring gear) mostly act as a motor to drive the car (it also act as a generator in regenerative breaking).

For your other questions, do a search here on PriusChat and you will probably find all the newbie answers and then some.

[cmalberto]

Maybe there is a FAQ sitting around somewhere. I am always hesitant about asking questions of the like as they probably have been answered numerous times and of numerous opinions. Searches are good but sometimes with the questions aren't so specific, they are quite difficult to hone in on that keyword or two. And then sometimes you just overwhelmed with too much information.

Then sometimes in the effort to not spend hours and hours of valuable time, you simply just ask the question in hope of someone offering an answer, a link or sharing their valuable opinion.

Thanks for the answers to the acronyms. They do make sense.

--Mickey

[OZ132]

Regardless of what vehicle I'm driving, it is my habit to drive gently while the ICE is warming up, to avoid undue wear and tear on the cold engine. I don't think the Prius will change my thinking is this regard?

[a64pilot]

Originally Posted by OZ132

Regardless of what vehicle I'm driving, it is my habit to drive gently while the ICE is warming up, to avoid undue wear and tear on the cold engine. I don't think the Prius will change my thinking is this regard?

It hasn't mine. I even allow the engine to warm itself before I drive off and regularly average 60ish on the MPG on the consumption readout, but it's warm weather here too.
And I'm the guy that never goes into the power portion of the HSI on four lane roads, but I'm almost always in the right lane too though.

[morpheusx]

The Prius is designed to use more battery power at warmup to keep the rpm's lower while warming up. It is best to let the engine warmup at slow speeds especially the type that allows you to basically creep around at near idle speed. Basically my rule is to stay under 35 mph for the first few minutes. You also want to be able to have a 6 second stop somewhere early in your trip to force the engine further along in its warmup cycle, but that's another trick all together.