Question from a Gen3 Prius owner

no worries, don't take internet postings the wrong way. it can be hard to determine intent. i think we would all like to know definitively if gen 4 has different cold start behavior than gen 3, and not just everyones individual experiences.

and most of us agree that it would be nice if toyota programmed a minute or two delay under a certain speed so we could move a cold car around without the engine starting and going through the warm up cycle, or having to be shut down prematurely.

it has been a complaint as long as i have been a member, and some thought the ev button on gen 3 would solve it, but no dice.

 

In a case where the engine will start up when you put a 4th Gen Prius in "ready", say due to low ambient temp:

What is the grace period, from push of start button to engine start up?

On 3rd Gen it's about 15 seconds.

 

I've had mine start in 3 or 4 seconds. I know I have to hit that EV Mode button quickly if I want the best chance of driving off silently.

 

Yeah, I'd guess about 5 seconds, quicker than my old Gen 3 and Prius+ (V) were.

 

interesting stuff, thanks!

i hope to be in orlando in january, let's hope it doesn't cool down too much

 

They changed something, yes, and it seems like they are using the battery more aggressively. It's a balancing act, and hopefully they haven't gone too far.

 

but why haven't others reported so obvious and dramatic a change?

i would think this would have been all over the boards the first summer, it is a huge change, if true.

 

A lot of new adopters? I really think this more aggressive battery use is key to the 4th gen's mpg stats.

 

the engine is more efficient

li-on in most models

 

The warmup never seemed strange to me considering that it fits probably 99% of startup situations. Normally when you start your car you will be driving somewhere and unless you have switched to EV you will be needing ICE relatively soon after startup. However even in those cases you also don't need it in the first few seconds because you are normally either starting from your garage, parked on a residential street, or in a parking lot, which means in almost every case you will start out moving fairly slow. But usually within a minute or two you will be hitting the gas as you pull onto an actual road and have to accelerate. So I just assumed they thought it was better to get the gas engine started ahead of time so that it would be ready when needed at full power. And maybe also better for the life of the engine and/or battery. Obviously some individual owners may have a different situation at times but again I would think 99% of startups overall fall into one of those categories.

So it is interesting if it has changed. Either they decided after all of the years of experience that the warmup never really was needed, or maybe it is related to changes in engine and battery that now make the warmup unnecessary.

 

The top speed threshold for electric-only was increased a lot too. Our 3rd gen invariably kicks in the engine around 72 kmh (~45 mph). Four gen is a lot higher?

(I have a long/steep downhill where I can see this, eastbound at the west end of the Barnett highway. Speed is 60 kmh at top of the hill, it drops for almost a km I think, and just beyond the bottom the speed limit is 80. Just momentum, and the slightest touch on the gas to dispel regen, and you'll free-roll past that 72 kmh barrier, see consumption meter tick on, and feel the engine.)

 

Well, the temps around here in NE Ohio are in the low 30s (Fahrenheit) today like they have been for a few days at least. As soon as I got in the car this morning to back out of the garage (around 40 degrees I would guess) and put the car in reverse, the engine started. That's the same engine behavior as has been the case ever since the outside temperature has been less than what the temperature has been set at for the car's hvac system (set on Auto).

 

see post 2

 

thanks, can you expound?

 

As far as the top speed for the electric motor only power, I've been able to cruise at 60 to 65 MPH on the expressway routinely if I power up to that speed with the engine and then then back off the accelerator pedal and subsequently apply just enough pressure to hold the speed constant. Of course at this speed, you need to be on level or a downward slope for this technique to work for more than a few seconds. I believe that same technique of "accelerate and glide" is why I was able to consistently get around 65 MPG consistently at least up until the weather turned colder. The engine now runs more often just to heat the cabin and I'm only getting around 57 MPG.

 

and how about the thread question, cold start ev?