Why do diesel semi-trucks always leave their engines running at idle.?

Usually it’s because they are always wearing flannel and have huge beards in the middle of the summer so they need to keep the A/C on 24/7.

It costs more to stop the engine and restart it than keep it going. I wouldn’t ave known either but I asked my husband when he was a trucker.

yup at idle it is cheap to run to restart is $$$$ more

In winter you dont want to shut off a semi because you have more of a chance of gelling up. And now more companies like norsemen have power packs by thermo king to run refrigerators, micorwaves, heaters, air conditioning, and stereos. For an eighth of the cost that might be what your hearing. Also semis dont use that much fuel when there idoling.

It only costs more if you start it again within a few minutes. If you let it idle for hours, then it does cost more in fuel. Alot of trucks are using small generators onboard to deal with noise laws and also less fuel use to run the lights and A/C.

Diesels can be hard to start in cold weather (if not plugged in). Some have pneumatic starters. If for some reason it will not start immediately, it is not simply a matter of hooking up jumper cables.

Some need to operate refrigeration or AC for the load or sleeper cab.

But I imagine the main reason is not wanting to be stranded with a non-running engine.

My truck uses 0.3 gallons per hour at idle. Most use anywhere from 0.3 to 0.5 gallons per hour.

What’s more, a truck driver’s truck is his or her HOME while on the road. He or she sleeps in there, relaxes, watches TV, surfs the Internet….some of us even cook & eat in our trucks. Many of us also have pets, and wouldn’t dream of endangering THEIR life by leaving them in a too-hot, or too-cold truck.

You wouldn’t want to try to sleep in a vehicle, in the Arizona desert, in July, 110 degree heat, with no air conditioning, would you? Would you want to try and sleep in North Dakota, in January, 10 below, with no heat? Even more “moderate” temps….70′s and 80′s, can make the interior of a truck quite hot and uncomfortable, just like it does to a car.

For many drivers, idling the engine is the only way to keep their home climate controlled and comfortable. Truckers need a good quality, sound sleep period to be safe on the highways…..without the ability to keep the in-cab temperature comfortable, we’d have a bunch of sleep-deprived truckers running the roads. Who wants that?

Many companies are installing APU’s and generators to provide climate control and electrical power while the truck is sitting still. Yet these systems can cost upwards of $6,000 dollars a piece……for many small to medium sized fleets, the cost of equipping the entire fleet with APU’s, and the cost of maintaining the APU’s, is too much to bear….especially when many companies are already struggling.

The best some companies can do is offer “idle reduction incentives”….pay bonuses for drivers who take steps to reduce idle time. However, in the hot summers and cold winters, idling the truck is often a necessity, and driver safety & comfort takes precedence over saving a little bit of money.