Stupid Prius Advice Columnist of the Day

<div class='quotetop'>QUOTE(V8Cobrakid @ Dec 20 2006, 09:34 PM) [snapback]364958[/snapback]</div>

Engine RPM is one of the parameters I have always showing on my CAN-View, so I can assure you that the engine rpm goes all over the map, from low to high and everything in between, depending on load, battery SOC, and probably other factors as well. In particular, floor it and the engine rpm goes way up. But depending on conditions, you can see engine rpm anywhere in between the two extremes.

 

<div class='quotetop'>QUOTE(daniel @ Dec 17 2006, 09:29 PM) [snapback]363558[/snapback]</div>

A minute or 2?!? True Prius drivers LIVE in the slow lane! :^)

 

<div class='quotetop'>QUOTE(hill @ Dec 21 2006, 09:41 AM) [snapback]365179[/snapback]</div>

We do? Then why in the heck do I have my HOV stickers for the car pool lane then? B)

 

Okay, here's my scenario in particular...this is what's gotten me thinking about this in the first place.

I live about a mile or so from the freeway. Between the onramp and my home are level 25mph suburban roads.

But, when I merge onto the highway, there is almost immediately a moderate hill of decent length, which requires the engine to come under what I assume is (for it) significant load, based only upon what I hear on acceleration.

What concerns me is that, I'll start the car and the ICE goes through its warmup stage to light off the cat, etc. But it's never really been under much load at all, I suspect the coolant is barely warm and the oil more or less cold...and I'm almost certain that the temps of things like the crank and rods and all the heavy rotating parts at the bottom of the engine (not to mention the block itself) are probably all over the place, and so are the tolerences.

Anyhow, after about five minutes of trolling and sitting in traffic, I'm suddenly accelerating to freeway speed and then immediately on that upgrade (and, depending on traffic, not wanting to be run over by a truck).

I don't have CANview or anything like that, but it sure sounds to me like the engine's willing to give its all, at least RPM-wise (although I don't know if the throttle's open all the way, of course). But, to me, high RPM before the temps have equalized is not a smart way to run an engine. Regardless of load.

I guess sometimes I wish that a resonably observant driver retained the option of keeping this sort of thing under his/her control...then again, lots of times I'm not to be trusted, either...

It was nice to be able to short shift if I wanted to, until things warmed up; I'm missing that about my Prius more and more. I *really* miss the oil temp gauge in my Porsche.

 

Pinto Girl,
Good point, we all should adjust to the way we drive and the roads around us. For me, the roads are all flat. So when I wait to warm up, I am already going 34 mph on a flat road when the ICE kicks in. Then I accelerate to 40 mph and hold it there for another 10 minutes. I guess no one rule is correct for every driver or route.

 

<div class='quotetop'>QUOTE(Tempus @ Dec 21 2006, 09:20 AM) [snapback]365162[/snapback]</div>

Interesting observation, Tempus. I asked my wife, and she said "NO", that Auto Climate Control was OFF. I'm not surprised, as she dislikes "automatic climate controls" in general, prefering to adjust temperature and airflow manually. I then asked if she had the defroster on, and she said "YES."

To make what buttons she might have pressed more clear, refer to Toyota diagram 27P165a in the beginning of Section 2-9 of the owner's manual. Buttons 9 and 8 were on, button 6 was off.

However, according to 2-9-b on page 295 of the 2006 Prius manual, having the defroster on sets the AC to operate. This is common to a lot of cars, as the AC helps to dehumidfy the defrosting air. So we do have the load of the A/C, as well as the electrial loads of the rear window and rear view mirrors to contend with.

Now, I presume that "Bob", the original questioner, would likely want to utilize the same creature comforts as he prepares to scoot onto the freeway for his morning commute, so the fact that the defrosters were on doesn't necessarily invalidate the test in real world conditions.

However, for curiosity's sake, I'd like to time the cold start idle again, with the defrosters off. Not sure when we will get another 32 degree morning again out here in the wild west, but when we do, I'll make a request to have everything off, even the radio, to see how long the ICE takes to warm up till it shuts off.



Incidently, the Prius Owner's Manual also states, in Section 1-2:

The gasoline engine may not stop automatically in the following conditions:
- During gasoline engine warm-up.

_

 

<div class='quotetop'>QUOTE(Pinto Girl @ Dec 21 2006, 10:34 AM) [snapback]365211[/snapback]</div>

Natalie:

Although I am not a mechanic, I think you do not need to worry. It only takes a minute or two for modern engines to be warm enough to be driven under load. I'd say that 5 minutes of surface-street driving should be more than enough. And if the weather is cold, then presumably you have the heater on and the ICE is not stopping at stoplights. You have a head-start on warming up because of the thermos, and the oil should warm up rapidly because it is in direct contact with the metal, which is heated by the combustion.

I think you are fine.

If you are still concerned, you might PM Galaxee, whose DH is a Prius mechanic.