Stupid questions people ask you when stopped

[slide]

Originally Posted by helion42

I've heard of this, and it makes sense although it would be more effective to just turn off the engine if you're going to be waiting longer than 30 sec.
More electrical draw = more alternator output to compensate battery and increased resistance = more drag on the engine thru alt. belt = increase in consumption. Of course it's pretty small differences, but when you pinch every penny I guess it adds up.

I am not sure that in those days, with those ancient engines fueled by those carburetor devices, that turning the engine off for a minute's stop would save fuel. Perhaps we have an expert on antique engines here who can answer factually.

[scottrnelson]

Originally Posted by slide

I am not sure that in those days, with those ancient engines fueled by those carburetor devices, that turning the engine off for a minute's stop would save fuel. Perhaps we have an expert on antique engines here who can answer factually.

If you can start the engine without pressing the gas pedal down, which should be the case when it's hot, it doesn't use any extra fuel at all to restart an engine. On all but CV carburetors (usually only on foreign cars, like the 240-Z) if you pressed the gas pedal down the accelerator pump squirted more fuel into the carburetor. Normally when the engine was cold, you would press the gas two or three times which would both squirt more fuel into the intake and set the automatic choke, then you would start the car. This would be the case for American-made cars from the 50's and 60's.

So if it could be restarted without pressing the gas pedal down at all, even 20 seconds would save fuel.

Modern fuel injected engines would be even better, because they don't squirt in any extra fuel.

[bwalsh]

Originally Posted by Benesesso

Way back ~1964 in the USAF my crew got to visit most of the S. American capitals. In some of those countries drivers would turn off their headlights at every red light. Cabbies said it was to "save gas".

Wonder if they still do that.

Never heard the "to save gas" explanation but I have heard of people in here in the States who think that using the headlights unnecessarily is bad and will kill the battery...like there is no charging system.

Where do they get these people?

[Nadgett]

Originally Posted by EastSideSM

Mods, can you change this thread name to "Innocent questions people ask to make small talk and replies by self important jack-asses"?

Just the other day I... oh, never mind.

[Vertical C]

Originally Posted by bwalsh

Never heard the "to save gas" explanation but I have heard of people in here in the States who think that using the headlights unnecessarily is bad and will kill the battery...like there is no charging system.

Where do they get these people?

At lights wouldnt it be running off the battery not the alternator? The revs would be too low.

Like everything there is merit, but it might be insignificant.

[atomicalex]

An innocent colleague who is painfully American, on the phone....

IC: are you going to bring your bike back when you come home?
Me: I hope so. Have to check with NHTSA on that.
IC: Why, is it like right hand drive or something?
Me: Uh, no, I think there is an issue with the gas tank......

[Kannonball8]

On turning off headlights or shutting off engine at stop lights. I have no idea what the savings would be to shut off the headlights but I really think it would be almost too small to measure - lighting load = 2 x 55w headlights + 2 x 20w taillights = 150w or about 1/5 hp tops (750 watts / HP) for 30 or 40 seconds. But the shutting down the engine thing is what bugs me, maybe you can save a small amount of fuel, but, what about wear on the starter and battery? I start my car in the morning and drive 12 miles to work, I have the possibility of getting stopped at 4 traffic lights during my drive. This could give me a total of 5 starts each way or 10 per day instead of 2 per day. If I only use the vehicle to go to work and I work 240 days per year, I'm starting the vehicle 2160 extra times a year. You can't tell me I'm going to save enough gas to cover the starters and batteries (and maybe ignition switches) I'll use up. (or am I completely wrong?)
Bruce

[slide]

Originally Posted by scottrnelson

If you can start the engine without pressing the gas pedal down, which should be the case when it's hot, it doesn't use any extra fuel at all to restart an engine. On all but CV carburetors (usually only on foreign cars, like the 240-Z) if you pressed the gas pedal down the accelerator pump squirted more fuel into the carburetor. Normally when the engine was cold, you would press the gas two or three times which would both squirt more fuel into the intake and set the automatic choke, then you would start the car. This would be the case for American-made cars from the 50's and 60's.

So if it could be restarted without pressing the gas pedal down at all, even 20 seconds would save fuel.

Modern fuel injected engines would be even better, because they don't squirt in any extra fuel.

Those accelerator pumps didn't have temp sensors to shut them down?

Sure, today it makes great sense to shut off if you have a hybrid to start on the electric motor and then the engine kicks in right off such as the Prius does. Presumably, after about 30 seconds, the energy it takes to regain battery charge is less than the fuel spent idling. I'd guess some engineers have figured this out long ago which is why, to my knowing, all hybrids do this.

[hoadie72]

Originally Posted by Kannonball8

But the shutting down the engine thing is what bugs me, maybe you can save a small amount of fuel, but, what about wear on the starter and battery? I start my car in the morning and drive 12 miles to work, I have the possibility of getting stopped at 4 traffic lights during my drive. This could give me a total of 5 starts each way or 10 per day instead of 2 per day. If I only use the vehicle to go to work and I work 240 days per year, I'm starting the vehicle 2160 extra times a year. You can't tell me I'm going to save enough gas to cover the starters and batteries (and maybe ignition switches) I'll use up. (or am I completely wrong?)
Bruce

Those tiny savings across an hour or two's commute per day per week per year add up to considerbale savings.
As for additional load on your battery and starter - if your engine is warm and is maintained there is insignificant wear and load on your battery.

You're obviously not aware that most car manufacturers these days have cars who's engines automatically stop and restart in traffic. These engines are fitted to more or less regular petrol and diesel cars (ie not just hybrids). It helps give them the edge with fuel economony and while I haven't tried it, reviews I've read have said that it works flawlessly - well in premium brands anyway.

[scottrnelson]

Originally Posted by slide

Those accelerator pumps didn't have temp sensors to shut them down?

It sounds like you have no idea what an accelerator pump is.

It was something inside the carburetor that squirted extra fuel into the intakes every time you opened the throttle. It was there to make up for the air being able to speed up more quickly than the fuel and helped keep the air/fuel mixture more correct. Usually it was either a plunger (think of a syringe) or a rubber diaphragm. It was 100% mechanical, so no temperature sensors involved. As far as I know, the ONLY temperature sensor of any sort used in American engines in the 50's and 60's was the cooling system thermostat that regulated how much water went to the radiator.

[Phlemdog]

Those cars that have the auto shut-off, that are not hybrids, have huge heavy duty starters. Hybrids don't use their starter motor unless their battery pack is drained. It's all the electric motor's doing (pretty trick stuff).


On a normal car, even when warm, if you are constantly starting and stopping it, you will wear that starter motor out much faster then normal.

[DAKEZ]

** than **

[Thanantos]

Originally Posted by DAKEZ

** than **

You rang?

[Phlemdog]

Originally Posted by DAKEZ

** than **

[hoadie72]

Originally Posted by Phlemdog

Those cars that have the auto shut-off, that are not hybrids, have huge heavy duty starters. Hybrids don't use their starter motor unless their battery pack is drained. It's all the electric motor's doing (pretty trick stuff).


On a normal car, even when warm, if you are constantly starting and stopping it, you will wear that starter motor out much faster then normal.

Let's put this in perspective. A typical family might start and stop their car engine 20 times over a weekend and god knows how many times during the week. That starter motor will last 20+ years. So starting and stopping it during a few times during a commute isn't going to make a lot of difference.