when making many short trips 1 - 6 miles for example like a delivery service is it more economical to turn the car off between stops or let running avg stop 3 -4 minutes tks
For 3-4 minute stops, absolutely turn it off. You will replace the starter every few years, but the savings in gasoline and other engine components will make up for it. Then there the air pollutant emissions you will save, and no kid will take a joy ride in the vehicle you left running.
I would turn it off for a three minute stop. Consider the hybrids. You leaving it on would be like old technology and turning it off would be hybrid type technology. This would be doubly important to turn it off if you would not be in the car.
Note: Since you do not have a hybrid with all the technology, you don’t want to turn it off at every street light etc.
Shut off the engine whenever you can. A running engine is getting ZERO miles per gallon.
Most cars with four cylinder engines burn about .3 gallons per hour while idling, some a little more and some a little less. V-8’s can burn .5 to .8 gallons per hour. V-6’s kind of split the difference. This is for gasoline spark ignition engines. Diesels have an idle fuel consumption that is about 1/3 that of gasoline engines.
The general rule used to be if you are going to be stopped for more than one minute, shut it off. I think it still sounds reasonable.
Don’t know about where you live, but here in Colorado Springs, it’s actually illegal to leave a vehicle parked and running without anybody in it. Not that the law gets enforced that much.
The real issue is theft, and injury if the vehicle moves that you should consider.
UPS has studied this issue extensively and implemented policies to save fuel. It’s more economical to shut it off.
Driver not in seat – engine off ( FED-X ).
It won’t stolen if the keys are not in it.
It will save a tiny bit in fuel shutting off. In the global scheme of things it will save a considerable amount of pollution to the air.
i make deliveries in my van,and as an experiment i would turn the engine off every time i stopped including red lights,and the diffrence was,that i got 2 mpg more out of a tankfull,so it does save a little fuel.my van here in the uk is a vauxhall corsa with a 1.7 litre turbo diesel engine,and i get 38mpg in town,if i leave it running,or 40mpg if i turn the engine off at every opportunity.so theres not a massive diffrence!