operating temperature

MEXICOWANDERER wrote:
"Want to screw up your driveability? Put a LOWER Tstat in the engine. Doug"


I love it. A general broad sweep statement versus reality.

Yes if a 160F thermostat is used it will certainly harm emissions, driveabilty, and even the lifespan of the engine.

But, I went back and I looked and looked for such a disparity in my post. All I found was a 194 - 200 degree value.

Hypothesizing is a funny thing. It brings out the dreaded monster extrapolation. As an argument against, never use a verbatim opposing view. Always "extrapolate". Higher, lower, colder, hotter, quieter, louder than what the opposing viewpoint clearly states. This can be be accomplished by simply using a cognitive with no set value.

The idea is to allow an engine to operate at optimum temperature. If an individual deludes themselves that an "average" pickup truck operates at the same engine temperature as a motorhome then that's OK if that individual does not profess that "It means the same thing".

I have too many years experience to fall for delusions. One of the things I rely on heavily is common sense. If a pickup truck's normal operating temperature is say 216F it is of factory calibration and therefore correct. If that same drivetrain is installed in a NON FACTORY chassis and operates fifteen or more degrees hotter, which value would you believe to be "correct"?

If reducing temperature to that of the factory pickup truck is harmful (hello?) an emissions test will reveal it in a heartbeat. California emissions tests are not pass/fail. They use numbers and they use a spans. A range of acceptability that meets compliance. Or not. Emissions tests include HC CO and NOX among others. It isn't a static test. Motor vehicles are put on a chassis dynomometer and tested under load. And idle, and high idle.

By comparing vehicle tests, before and after, it is positive proof of an impact or not of doing any maintenance or adjustment. One does not CAUSE driveability problems and not see it in an emissions test. To argue the point would border on the ridiculous.

So the idea is to ADJUST engine coolant temperature to reflect that of a NORMAL PRODUCTION FACTORY (Means Ford, GM or MoPar) MOTOR VEHICLE. Normal means range. Acceptable min/max temperatures.

What I am saying is it would be foolish to endure the ramifications of a borderline too hot engine. If 20 degrees can be subtracted and still remain within the range as recommended by OEM it will save money.

The motorhome builder could give a dham if your hoses last four years rather than eight. It could care less if your chassis batteries last three years rather than seven. It could care less if a throttle position or crankshaft position sensor lasts four years instead of ten. Excessively high heat destroys stuff needlessly.

"The Extrapolator" will take the above statement and goose it to try and include every RV in all parts of country, in all driving conditions in every season of the year.

An intelligent person will weigh facts and come to a conclusion such as:

My rig does not run hot or does so very infrequently
I live on Vancouver Island it never gets hot here.
I simply do not drive when it gets broiling hot
I live and vacation in flat country

Or, the best one...

I simply don't give a ****

I have had to fight this issue for forty years with regard to underhood chassis batteries, extremely high heat and phenomenal rates of grid corrosion. Simply reducing engine coolant temperature to NORMAL helps. Forced air cooling helped even more.

This brings up a question not related to batteries. Two questions...

How many of you know for a fact what temperature the transmission fluid is on the RETURN line from the transmission oil cooling device?

How many of you have installed a transmission cooler or substituted a larger transmission cooler?

I apologize for dealing in reality. A bad habit I guess...

You are pretty smart, But, like a LOT of smart people you are NOT that smart in all things. MY post was in response to 40 years as an RV Technician. I have seen all the silly things RV'ers have tried with using lower tstats to keep the engine running cooler and the problems they experience. Now, You seem to think Chevy/Workhorse and Ford build Class A and Class C chassis for someone that does NOT install a RV on them. They take into account the weight and design for what the RV maker is doing with the chassis. Those RAW chassis's are BUILT for an RV, nothing else. You USE the control systems that are designed by the Chassis makers. Doug