Idleing

A gallon per hour.

 

At low idle, figure a minimum of one gallon an hour. Bump the idle up to 1200 or so (High Idle) and figure that you will be on the high side of 1.5 gal per hour.

But, don't forget that part of the cost of idling is that it is just about the worst conditions for your motor that there are. It does not produce enough heat at idle to keep the coolant fully up to temp, and the cylinder temps are low, resulting in the fuel not burning completely, and you end up with increased fouling and residue in the oil. Also, you are spending component hours on non productive time, while you should be concentrating on making every minute the engine is running a money making one.

There are alternatives, such as APU's, which can be used to reduce main engine idling time, or installed heaters, which burn diesel fuel and reduce cold weather idling. The arent as effetive as an APU, but they will give you an easy 50% reduction in idling time for about 1/6 the cost of an APU.

But, no matter what systems are installed, the amount of idling is solely in the hands of the driver, and if he isn't committed to cutting down his idling, the percentage of idle time will remain high. All those little 5 minute idles while you run to the bathroom each day, or check in at the guardshack, add up.

 

Main engine? Do big trucks have secondary engines? This is embarrassing, but I really do not understand, unless you are refering to keeping the truck engine running instead of perhaps individual motors that may be run independent of the truck's engine...?

Sometimes, I feel like a fish outta water here.

 

I believe he's referring to a bunk heater engine or APU engine

 

Burky the older trucks you high tacked them. What about the newer ones?

 

Thanks, minpins! I'm so clueless sometimes.

 

In order to MAKE a Volvo or International truck idle as long as YOU want it to without stalling, you have to bump the idle up to about 8 or so rather than the usual slow idle it has when driving. Usually between 8 and 9, it won't stall at all.

 

No, you're not clueless, just new We were all there at one time or another

 

I limit my idling as much as I can, but when I do idle, I will often bump the idle up just a hair. At the lowest idle speed, there is a vibration frequency that I find annoying, and if I move the throttle setting up just a hair, maybe 50-75 rpm or so, it disappears and the vibration is gone, which makes my sleeping much more restful.

I have encountered some people who go bananas with high idle, and one time this summer somehow managed to have a guy pull in next to me that idled the truck about 1400+ rpm all night long. I had to shudder to think how much fuel that truck burned through the night.

Newer engines are not as sensitive to high idle as some of the older ones were, and in some cases the manufactrers recommended a high idle to keep the oil circulating at more than the minimum rate. Many hours of idling with the oil barely flowing had the potential to do engine damage.

Yes, I was referring to the APU when I made the main engine comment. If you have an APU, then in effect you have a second engine onboard that will do the work of heating and cooling, and take care of any hotel loads, such as electrical and other things. So I referred to the main engine in that case.