Do all Priuses race the gas motor for the first 5 minutes?

http://priuschat.com/index.php?showtopic=2...p;hl=user-guide


The above links to an excellent article written by an experienced poster (john1701a) that will answer many of your questions about how the Prius II (2004-2007) works. Short answer is yes it's normal to run the ICE for the time required to bring the temp up to about 73 degrees Celsius for optimal efficiency. If I did not post the link correctly just search for user-guide written by john1701a.

 

Neicy is correct in saying the ICE (internal combustion engine) likes to run to warm itself up, but it doesn't "race," at least not as I define it. Specifically, it runs at about 1200 RPM. What do you mean by "race?"

 

I wouldn't use the term race either. They all start the ICE to warm the engine and catalytic converter, but the ICE runs at modest RPMs, unless, of course, you goose the gas.

Tom

 

When I go out and drive 5-7 miles in traffic in hot weather I often make a stop and run in to post office or wherever. When I restart it one minute later it goes into a fast idle mode for a couple minutes, like from a cold start. I find this annoying as I think I know better than the computer But it isn't "racing." I've learned to accept that it must be doing the right thing. So if this is the same as you describe then it must be somewhat normal.

 

<div class='quotetop'>QUOTE(Howell @ Aug 29 2007, 12:23 PM) [snapback]503941[/snapback]</div>

How long it runs depends on how cold it is outside. During the Winter, mine would run quite literally for 5 mins (and I live in San Jose, where it rarely gets below freezing). This was murder on the gas mileage.

But it sounds like it's the normal behavior you are encountering. Even in very hot weather, the engine always runs at least a short time after every startup, no matter how recently it was just running. Just the way it was designed.

The car is smarter than you (or I) are!

 

<div class='quotetop'>QUOTE(Howell @ Aug 29 2007, 04:23 PM) [snapback]503941[/snapback]</div>

Some people leave their Prius running when making short stops just to avoid the restart sequence. I don't, but I sympathize with them.

Tom

 

<div class='quotetop'>QUOTE(Howell @ Aug 29 2007, 01:23 PM) [snapback]503941[/snapback]</div>

This is one reason people have installed the EV mod. If you're moving around in a parking lot (or just backing out of the garage into the street), why have the engine running during that short time?

 

<div class='quotetop'>QUOTE(Howell @ Sep 3 2007, 01:25 AM) [snapback]506213[/snapback]</div>

It is a switch you can install that will replace some functionality missing in US versions due to emissions certification. Flip your EV switch and you can stealthily run over pedestrians without them ever hearing you coming. It will keep the ICE from running at low speeds as long as the battery does not need charging.

 

<div class='quotetop'>QUOTE(Howell @ Sep 3 2007, 03:25 AM) [snapback]506213[/snapback]</div>

EV stands for Electric Vehicle. Look in the modifications forum for how to install this item or buy a kit fromcostal e tech or sigma automotive. If your battery State Of Charge(SOC) is good enough...you can run up to 34 mph for about 2 miles. I know it is crappy range but a lot of people use the switch to force the ICE to turn off when it would normally not do so for hypermiling. One note is that if installed....and Toyota finds out that it is installed in your vehicle then your warranty is extinct....but if you own a salvage car like I do then you never had a warranty to begin with.....so I have been modifying as I see fit. Have you read the 5 stages of operation?? This would help with the explanation a bit. At minimum the ICE runs for a minimum of 57 seconds....in my car I have the scan guage II and I can see the tach. It tries to maintain 1280 RPM for those first 57 seconds. I can drive up to about 23 mph on a flat surface and accelerating slowly without causing the rpm to exceed 1280. Hope this helps. I will paste my new people blurb that may help you greatly. It takes some time to find the great nuggets on this site unless you have been pointed in the right direction by someone like ........well....ME.
Required reading.... go to this link and read about Prius power flow
http://priuschat.com/Introduction-to-Prius...low-t30286.html
The state of charge on the traction(HV) battery is controlled by a battery computer. The visible part of the battery you see is 40%-80%. The batt computer wants to keep the HV battery at 60%(5-6 blue bars) all the time. This is to maximize the life of the battery.
It is very hard to get your battery to 8 green bars unless you already have 6 blue bars and you go down a hill at approx 6% grade or better for about 3-4 miles(coasting preferrably). After this if you keep driving on a flat surface the car uses the excess energy to run MG2 to help power the car to draw the HV battery back down to 6 blue bars(approx 60%). If you have all greens all the time then the car has no place to store excess energy and must burn it up as heat to the environment through the MG's. The HV battery is what starts your ICE(gas engine).
Read the 5 stages of operation here(click on the HERE link in the first post):
http://priuschat.com/index.php?showtopic=4...amp;hl=5+Stages

Blocking the upper grill. I blocked my upper grill for summertime but not the lower. It forces the ICE to operate at slightly higher temps which makes it more efficient. The efficiency I speak of is due to the coolant circulating through the throttle body to pre heat the fuel and to keep the temp above 73deg C or 163deg F. The fans will still operate as necessary to keep your engine cool enough. Part of the efficiency is due to the engine staying warmer for longer and not needing to start as often to maintain temp. The other part of blocking the grill is to keep the heat in while preheating your vehicle with a Engine Block Heater (EBH) for approx 3 hours prior to operating your vehicle. I do not recommend blocking the grill unless you have the scanguage II to monitor engine coolant temps. Blocking the lower grill during extreme cold months will also give greater FE. If you can not keep up with the lingo then you need to read this:
http://priuschat.com/index.php?showtopic=1...l=abbreviations
hope all of this helps. Read often and tell other drivers about this site.....very informative.

When people say "Pulse & Glide" most people think push the accelerator then coast to recharge the battery......
This is not the true intent of pulse and glide. It takes some skill to do this properly. This is my recollection of P&G

1. PULSE Only pulse up to 40 MPH or below because at 41MPH the ICE will continue to run at 960 rpm even though the engine icon on your energy screen is not pink( lit up) to prevent MG1 from overspeeding. Yes I have the scanguageII and I have watched it countless times. It may spin but there is no way to tell if it is getting spark and sending fuel to the engine...just increased drag from the water pump on the belt, resistance on the crank and resistance from the pistons. If I am on a flat surface and doing P&G and get 41 mph by mistake then the ICE will not shut off(0rpm) until I reach about 39-38 mph so that is a few more seconds before the ICE stops spinning. To prevent exceeding 40 mph on a down hill slope, do not pulse up to 40...make it less based on how steep/long the hill is. I like to use regen to slow down if I know the rest of the down hill will take me where I want to go without more acceleration. While on this note I will say that above 45 MPH the wind drag is much higher and gets increasingly intense the faster you are above this speed(not linear). To test this get up to 45 mph on a flat surface and let off the accelerator. Time how many seconds it is to get down to 30 mph. Now do this for any speed above 45. Try 55 or 60 and wait till there is a 15 mph difference. Less than 45 the time is longer and therefore more fuel saved.

2. GLIDE. This is the point that you take your foot off of the pedal to force the ICE to shut off if you are in the proper stage of operation. Read the 5 stages of operation and click on the here link to help you facilitate when the ICE will and will not shut off based on what STAGE it is in http://priuschat.com/index.php?showtopic=4...amp;hl=5+Stages After you remove your foot from the accelerator you then must reengage the accelerator ever so slightly while watching the energy screen to observe a NO ARROWS CONDITION(not regenerating AND not providing propulsion...no green or yellow arrows). You might be thinking by now.....why is this so in depth??? It takes some SKILL, slight of foot or feather foot to accomplish this. You can not be eating, conversing on the phone and many other things while trying to stay in a P&G mode(unless you are highly skilled). It clearly takes some skill and knowledge to do this correctly. I am trying to provide you the knowledge and pass on the info I have for this. From now on when having a conversation about P&G you can pass the MPH threshold and No arrows conditions on so others know. When someone says glide in the future this is what comes to mind each time.

3 Do it all over again...try to watch for traffic lights and anticipate them so you can Glide. If you have a down hill ride home like I do for an entire mile prior to your drive way then you will master the downhill glide for battery recharge vs. no arrows glide condition. Good luck with this and keep us posted. If you feel this info is particularly useful and you have more input I will edit my post to accomodate your thoughts. Please advise through PM or click on my name and email me direct and please copy and paste the URL as I have many post so far on multiple threads.

 

<div class='quotetop'>QUOTE(Howell @ Aug 29 2007, 02:34 AM) [snapback]503665[/snapback]</div>

When starting from cold, the engine is noisier at a given RPM that when hot, due in part to variable valve timing that minimizes cold start emissions. Idle is a bit higher, as well. Combine these two, and you've got an idle that can sound to some like something's wrong. However, if your "check engine" light isn't on, I wouldn't worry about it.

Later hybrids, such as the Camry hybrid, are a bit more smooth sounding. Toyota is learning.

 

<div class='quotetop'>QUOTE(Howell @ Aug 29 2007, 02:34 AM) [snapback]503665[/snapback]</div>

I have a 2007 with 400 miles on it and it never races...it turns on with the slightest of shudders and well mannered never over idle but after reading the whole thread I wonder if its the ambient temp that makes it do that. I live in Florida where its been 90+ since I bought it so maybe its been cooler in Tx for you. Love this car !!!