Straight Weight vs. Multigrade

[SteveD2]

quote:

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Originally posted by widman:
A lot of theories to try to explain it, so here is another question. Truck makers do not have to comply with mileage standards. They sell the big things based on how many million miles they can run with the big guys on long haul and delivery routes.
Volvo won't recomend any thing but 15w40, Scania, Mack, Caterpillar, and Cummins the same. Why?
I've seen the videos of the Volvo VDS 2 examination. 320,000 miles of heavy work with 40,000 mile drain intervals. Take the engine apart and can't have that ridge on the sleeves, nor other signs of wear.
If there is any truth to lower wear with single grades, why don't they use them?

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The same engine in an industrial application, generator, etc., will probably have a straight 40 wt. oil and heat on the engine when it's shut down. You don't want to start a cold engine with 40 wt...if indeed it'll crank fast enough to start. The straigh 40 is cheaper.

Ken

 

[dragboat]

Quote:'
"In the next 3000 KM, the vehicle saw only our regular rural/highway driving and the engine had used almost no oil, (down just a little on the stick) It was only when the vehicle did another stint in the city for a week that it used almost another litre of oil."

Anther factor that "might" explain the aditional oil usage in the city could be detonation in the stop and go city driving,often detontation is inaudible and could explain the increased oil use by the loads given to the engine while starting from stops ,,this is "if" it is detonating. Especially in summer heat,even with a knock sensor a engine can detonate and it takes a moment for the timing to be pulled by the computer is a FI motor. I am guessing all here knows the extreme pressures detonation or preigntion causes in the combustion chamber and the rings cannot take that type pressures,niether can the piston ring lands repetedly,anyway,just a thought.

 

[MolaKule]

Dragboat,

Interesting thought. Preignition would certainly heat things up, and as you said, it takes a few cycles of revolution before the computer pulls back on the timing, which in turns heats things up even more.

 

[MolaKule]

BTW,

Everyone have a safe and productive Holiday!

 

[Patman]

quote:

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Originally posted by MolaKule:
BTW,

Everyone have a safe and productive Holiday!

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And you as well! Up here our holiday is called labour day, instead of labor day.

My weekend will be productive, tomorrow we're putting in my new car audio system, and then on Sunday I have decided to drain out the Maxlife and put in the Schaeffers finally! I was going to wait until next weekend, but my analysis kit arrived from Terry today, and I figured I've gone far enough on the Maxlife. My original plan was to take it up to about 3500 to 3700 miles, but by Sunday I'll be at about 3300 miles, that's close enough for me.

The sooner I get this stuff out, the sooner the moly can finally get into my engine, and then the sooner I can finish up the first Schaeffers interval and have it tested too. Terry is going to be able to retire just on the business from me alone!

[ August 30, 2002, 08:05 PM: Message edited by: Patman ]

 

[MolaKule]

"Terry is going to be able to retire just on the business from me alone!"

He is getting all my new samples now as well.

 

[Terry]

Thanks for the business, and please allow me to retire ! I'm sick of traveling 15+ days a month.

 

[userfriendly]

Molakule;
This was the thread I was lookin' for.
"laser fluorescence" to answer question de jour.
Multi-grade engine oils did not wet the top ring as well as single grade motor oils.
Did I read that correctly?
(My understanding would then be......)
Therefore, single grade newtonian oils provide superior lubrication and anti-wear performance than multi-grade non-newtonian fluids.
Could (up-start) Detroit Diesel tm, have been right all along?