JaxDad wrote:
Since somewhere back there I was asked to quote the Cummins info on NOT idling, either for warm-up or to cool down.
Here it is;
"Engine Warm-up
Idling the engine for warm-up is not necessary. Operate
with a light throttle and limited RPM until coolant temperature
reaches approximately 150ºF.
Engine Cooldown
Prior to shutdown, an engine should be idled 3-5 minutes
after extended full throttle or high power operation. However,
under normal driving conditions, such as exiting a highway,
engine operation is generally lighter in nature and thereby,
the 3-5 minute cooldown is not necessary."
Which comes from this Cummins Publication.
As was stated previously, at idle (700 rpm, not 'fast idle' of 1200 rpm plus exhaust choke) diesels make no useful heat, so driving off gently makes far more heat, and far faster, which is why that is what the manufacturers recommend drivers do.
For those with air suspension, and who use it to let the motorhome 'stoop' when parking, unlike OTR trucks, it's a simple plumbing job to reconfigure the dump valve and add an extra tank or two so that it's ONLY the air bags themselves that empty, NOT the entire system.
I did this on my Freightliner, now I have 120 psi when I start up and charging the air bags only drops the system pressure to about 50 to 60 psi, I'm back up to 120 psi in just a few minutes.
It also means I have a lot of air at 120 psi if I need to add air to a tire before I even start up.
Good idea. But, If you have a older unit there are probably enough leaks in the system so that if you set in one place for a few days the tanks will be empty. Or, at least that how it is on our Farm Trucks. The law allows you to leak a little just not so much as to compromise the safety of the air brakes.
