How does anyone know for sure whether the (80+) driver’s car might have been stalling or having some problems?
And why would it matter so much to someone who is in front of that person in traffic?
There are more important things to consider while on the road.
“I was implying the coolant is gets hot, and since the passages are part of the engine, the engine gets hot. I should’ve been more descriptive.”
You’re still missing the point. The engine does not get hot with the ignition off. It’s already hot. With the ignition off it gets cold. The coolant gets hot. The engine is transfering heat to the coolant, cooling the metal.
Without burning fuel there’s no source of heat, so it cools. This is really simple: No source of heat = doesn’t get hotter.
Jad2007 & VDCdriver,
Well done guys, I thought that was pretty clever.
First, let me ask, “Was he driving a hybrid?” If yes, the engine shuts off automatically when stopped.
Otherwise, the best teacher is experience. He MAY stop doing that when he realizes it’s cheaper to put more gas in his car than to keep replacing the starter. Often, as in this case, if someone’s actions are of no direct consequence to you, the best you can do for him is to MYOB.
Did you see the Mythbusters segment on “shooting fish in a barrel”? It wasn’t as easy as they thought
He may simply be trying to be a hypermileage driver. Perhaps he read this article: http://autos.aol.com/article/hybrid/v2/_a/the-pursuit-of-hypermileage/20071001102409990001
You mean he was in front of you to make a turn before you think he should have?
That got you ticked didn’t it?
He was behind you when he shut the engine off. Did it twice behind you.
No danger to you and no interference.
Given your response, better think of anger management before it gets you in trouble.
Some of the hybrids do shut down automatically when stopped.
Not something I would do even at long lights. Not worth the wear and tear on the starter.
Yeah the engine does get hotter with the ignition off. There's hot spots at the combustion chambers.. with the ignition off, these hot spots do cool off (since as people have said, there's no combustion occuring), BUT they cool off by shedding this heat into the rest of the engine. With the water pump and oil pump not running, there's no significant cooling *and the rest of the engine gets hotter* before it eventually air cools. If the engine is already running hot, shutting it down can easily drive the engine above the maximum design temperature (especially the heads, and possibly thermal breakdown of some of the oil, especially if it's not synthetic oil.)This is a fascinating thread. I wish I had gotten in on it sooner. 8&sand, learn to spell, especially when calling someone else an idiot. You don’t want to be the butt of jokes, do you?
Today on my commute to work, I found myself on my motorcycle waiting at a couple lights. I was not first in line and I know this route pretty well. So at the two lights I stopped at this morning, I shut off the engine. Knowing the traffic patterns at these intersections and the fact that I was not first in line gave me plenty of time to fire up the engine and put it in gear before the car in front of me started moving. My motorcycle only gets 48 MPG, and I am trying to get 50. Am I an idiot?
I have said it before and I will say it again. Being behind the wheel of a car or truck is like being in front a computer. The anonymity brings out the worst in some people. Face it, 8&sand, you only came here to vent your frustration because you don’t have the guts to talk to the old timer and learn something. Instead you come here and whine. That says a lot about who you are.
“There’s hot spots at the combustion chambers… with the ignition off, these hot spots do cool off (since as people have said, there’s no combustion occuring), BUT they cool off by shedding this heat into the rest of the engine.”
You yourself have just said that the heat is being redistributed. That much is true. The engine is not getting hotter.
Look, think of it this way: temperature is a function of how much heat is in something. Think of heat as being little packets of heat energy. For something (like, for instance, an engine) to get hotter there needs to be more packets of heat added. Higher temperature means more packets of heat in the same area, a heat packet density, if you like. What you are describing is moving the packets from one area of the engine to another. While one area may heat up, another cools, and that means the engine as a whole is not heating up.
The original point was about the engine getting hotter as a result of shutting the ignition off, overwhelming an incompetent cooling system. My point is simply that with the engine shut off fewer packets of heat are being created, therefore the weak cooling system has less required of it.
"If the engine is already running hot, shutting it down can easily drive the engine above the maximum design temperature (especially the heads, and possibly thermal breakdown of some of the oil, especially if it’s not synthetic oil.) "
Okay, suppose you’re right, shutting the engine off makes some parts of the engine hotter and bakes the oil. What would you recommend? Leaving the engine running makes the engine hotter. It’s still burning fuel, right? The cooling system is still not up to par, right? Shutting the engine off may make the engine momentarily hotter in some spots, but the engine is going to have to shut down at some point anyway, because it’s on the verge of overheating.
My point is still quite simple: with no fuel being burned there are no “heat packets” being created. The overall engine heat is therefore getting lower. Any localized heat escalations are not because the whole engine is getting hotter.
For the folks who think the engine will get too hot when shut off—actually the second law of thermodynamics requires coolant to go into natural circulation. Natural circ is much slower than forced circ, but as long as long as the radiator is colder than the engine block it will occur. Natural circ can be enhanced with cars that use electric fans by taking actions to turn a fan on. Enhanced circ has been incorporated into some electrical designs.
What the old dude was doing was hyperdriving. Hyperdrivers use low friction braking (think coasting to a stop) as much as possible, slowly increase speed until reaching their desired speed (55 to 60 mph hiway), and shut the engine down at all stoplights. Yeah turning the engine off and restarting it does cycle the starter, ignition switch, starter relay, but normally doesn’t wear the parts out for 3 years or so.
Read any hipermiler website and the “80+yr old idiot” isn’t so dumb… ‘assuming’ he’s got a late model car, he’s doing his part and saving gas - albeit just a little… think of the amount that could be saved if more did something similar.
Yep, you're probably the idiot......maybe his car died and he was just
starting it up again.
Patience 8&sand