Need help fielding common question regarding my Prius

pdxprius · 03-20-2005, 08:06 PM

Hello all.

My '05 Prius has truly been a source of intrigue for all my friends to whom I've shown it off ever since I purchased it three weeks ago. I usually am able to answer most questions they pose, you know, like "do you have to plug it in?", etc.. There has been one particular question, however, that I have not been able to explain. Maybe some of you can help me better understand how this car works so I can have a better answer for my buddies.

The question is: how can the Prius frequently start and stop the ICE while driving without burning through spark plugs/ignition systems? Does it ignite the ICE by a different mechanism? Any help would be appreciated, thanks!

KTPhil · 03-20-2005, 08:11 PM

The ignition system (and the fuel system) don't activate until the engine is spinning at about 900 rpm (spun up not by a conventional starter, but by one of the two electric motors). There will be no more wear and tear than on a conventional car.

In fact it can be argued there will be less, since (1) the ICE doesn't turn 100% of the time and (2) the plugs don't foul trying to start a motor spun at only 200 rpm or so as in a conventional car. And the "starter" itself has it easy since there is no solenoid and no ring gear teeth to engage. THis is another are where the Prius HSD may prove to be MORE reliable than an ICE alone.

Frank Hudon · 03-20-2005, 09:22 PM

the ICE is essentially an air pump, throw fuel and spark at it and it runs, take away the spark and fuel and it's an air pump again. Below about 40 miles an hour when the MFD say's the ICE is off it's not spinning over about 40 the ICE spins to protect MG1 from over speeding with or without fuel and spark as reguired.

03-20-2005, 08:06 PM	#1
pdxprius Join Date: Feb 2005 Location: Portland, OR Posts: 12 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Need help fielding common question regarding my Prius Hello all. My '05 Prius has truly been a source of intrigue for all my friends to whom I've shown it off ever since I purchased it three weeks ago. I usually am able to answer most questions they pose, you know, like "do you have to plug it in?", etc.. There has been one particular question, however, that I have not been able to explain. Maybe some of you can help me better understand how this car works so I can have a better answer for my buddies. The question is: how can the Prius frequently start and stop the ICE while driving without burning through spark plugs/ignition systems? Does it ignite the ICE by a different mechanism? Any help would be appreciated, thanks! __________________ 2005 Black (AM) #4

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
What do a Clean Prius and a Dirty HUMVEE have in common?	PriusOwner004	Prius Main Forum	3	10-05-2007 02:29 AM
Common Ground?	Wildkow	Fred's House of Pancakes	13	04-16-2007 12:13 AM
New Prius road noises is this common?	FishHawk	Prius Main Forum	12	06-29-2006 02:17 AM
Common Problems with the Prius	boostin	Care, Maintenance and Troubleshooting	3	06-23-2005 01:17 PM
Prius giveaways- getting common?	galaxee	Prius Main Forum	1	04-28-2005 04:17 PM

03-20-2005, 08:11 PM	#2
KTPhil Senior Member Join Date: Jan 2005 Posts: 1,213 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	The ignition system (and the fuel system) don't activate until the engine is spinning at about 900 rpm (spun up not by a conventional starter, but by one of the two electric motors). There will be no more wear and tear than on a conventional car. In fact it can be argued there will be less, since (1) the ICE doesn't turn 100% of the time and (2) the plugs don't foul trying to start a motor spun at only 200 rpm or so as in a conventional car. And the "starter" itself has it easy since there is no solenoid and no ring gear teeth to engage. THis is another are where the Prius HSD may prove to be MORE reliable than an ICE alone.

03-20-2005, 09:22 PM	#3
Frank Hudon Senior Member Join Date: Jan 2004 Posts: 4,144 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	the ICE is essentially an air pump, throw fuel and spark at it and it runs, take away the spark and fuel and it's an air pump again. Below about 40 miles an hour when the MFD say's the ICE is off it's not spinning over about 40 the ICE spins to protect MG1 from over speeding with or without fuel and spark as reguired.