My opinion is that no, I shouldn’t because chances are, starting and stoping the engine not only polutes more than when it is just running; but it will also puts pressure on other pieces that might break faster. The other problems I see is that in case of emergency you won’t be able to move quickly, and also that it’s damn annoying for passengers and driver.
However a good friend of mine really insists that he’s helping the environment by stopping the engine of his car at the red lights; and also that it’s not really that bad for the car; and finally that emergency situations never happen when you’re stopped at a red light…and above all, he doesn’t find it annoying…
So, what’s the straight dope?(please tell me I’m right)
I don’t remember what car these numbers were for, but the numbers I heard were about 1/2 oz of gas to start the car vs. about 1 oz of gas per minute to idle. That would make approx. 30 seconds the break even point. Of course, YMMV.
Starting motors and batteries are designed for infrequent use. Starting the engine repeatedly will likely result in having to replace the starting motor and battery more often which would negate any savings in fuel.
You can get dual powered battery cars that do exactly that. Engine stops when the car stops, battery kicks back in when you move off. Traditional petrol/gas fires up when required.
Apparently it very weird at first, as you keep thinking you’ve stalled.
The OP suggestion is the way ahead, but not practical or advisable for today’s car.
One of the cars that I use in my local car sharing association (a VW Lupo 3L diesel), when the ‘economy’ mode (3 liters per 100 km) is enabled, does stop the engine automatically if the car is stopped more than a few seconds, and restarts the engine when I take my foot off the brake. So frequent starting/stopping does seem to be economical at least for a modern car/engine design.
I have also frequently seen traffic signs telling drivers to stop their engine before railroad crossing barriers and at some traffic lights.
Tell him to stop it. As other poster’s have pointed out, he’s wearing out parts faster, including his battery, which won’t help the environment when those parts have to be tossed. I also don’t want to wait at a green light while he restarts his car.
I agree with the people who have said that with traditional cars it’s probably not worthwile. The stress on the starter etc will outweigh the energy saved.
However, there is a clear trend towards cars with high-voltage electric systems (And in this case high-voltage means 42V). The main reason for this is that modern cars have so much ‘entertainment’ that all requires electricity, so that it’s worthwile bringing up the voltage, in order to bring down the current, causing less magnetic perturbation and lighter cables.
In these cars the starter/generator would be replaced by a Integrated Starter/Generator, which has several advantages. One of them is the ability to start the engine very quickly - It has been proposed that the engine should switch off automatically whenever you stop - and then come back as soon as you press the accelerator. - In theory without any delay. An other is that you could use the 15kW or so extra power ‘on demand’ - which could lead to weaker/leaner engines performing the same - but will probably instead mean more power to existing engines…
My pop has been a mechanic for many, many years, and he always says this is a no-no. However, I have noticed that if he is at a light, a drive-thru, or railroad crossing , he pops the car into neutral - he says this causes less stress on the engine than idling in gear.
How about when the person coming up behind you locks their brakes because they were going too fast? If your car was in gear you could pull ahead a few feet and possibly avoid getting rear ended.
The emergency occurs three lights further up at a green, but affects you when a fire truck or ambulance needs to get through your intersection and you can’t move your car.
Does anyone know of any laws relating to turning off your car on the roadway?
If emissions are your concern, remember that during starting the car spews half-cooked gasoline out the exhaust, which I’m guessing is worse than cleanly-burned exhaust.
At any rate, put me down for wear and tear on the engine making it not worthwhile.
Well, I have a 2000 Honda insight. When I pull to a stop at a light the vehicle will turn itself off. Pushing in the clutch restarts it. This happenes every time unless the battery charge is low or the AC is running on HIGH.
It is designed to do this. Not sure why… but those crazy Automotive enginers decided to do it for some reason.
I also seem to remember when I was in Switerland (Basil) Quite a few people would turn the vehilce off when they came to a red light.
Yes, but the Insight is a hybrid. While the design of the hybrids is that under 15 or 25 or something like that you’re running off the battery, not the engine, normal cars aren’t designed that way.
