0w-40 Mobil 1

Al

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19,154
Location
Elizabethtown, Pa
That's an execllent question and will probably be debated here. [Big Grin] I would say "No" at strictly highway speeds. You have relatively lower load at higher bearing speeds which is easy for bearings. On the other hand Who is to say what percentage of the engine wear for a given oil change cycle is due to highway speeds. Heavy loads (mashing the accelerator) at probably lower rpms may constitute extremely high wear over a short period of time. ie. is one accelerator stomp equal to 100 highway miles. Also what percentage of the wear is due to starting up an engine. If you can believe what you read- it's like half your engine wear. Are we dealing with summer or winter? My gut feeling says wear could be improved in summer by using the 40 wt. Finally there are other parts of the engine-cams, rings/cyl, timing chain. Tough question to answer without knowing the characteristics of an engine. And even if I knew, I wouldn't have a clue. [freaknout]
 
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5,785
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Dixie
Buster, If you are indeed running at Autobahn speeds of 100-130 mph and seeing bulk oil temps of 240F-270F, the 0w-40 is going to give you a bit better protection - specifically from bearing wear. The old 0w-40 Tri-synthetic had a high temp/high shear viscosity of 3.6 Cp, so that's about 15% higher than their 10w-30 supersyn stuff. The HT/HS viscosity correlates pretty well to bearing viscosity - in fact that's the reason for doing the test at a high shear rate and temp. If you were doing heavy towing at low speeds, you might want to go to a 0w-40/5w-40/10w-40. Running at 70-80 mph actually doesn't load the engine much at all, so a 0w-30/5w-30/10w-30 synthetic is fine.
 
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3,216
Location
BC, Canada
Buster; With an HTHS of only 3.6 for the 0W40, you might as well stick to XW30. Delo 400 15W30 has a higher HTHS than the M1 0W40 you are referring to at >3.7
 
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9,783
Location
Saskatoon canada
Originally Posted By: used_0il
Buster; With an HTHS of only 3.6 for the 0W40, you might as well stick to XW30. Delo 400 15W30 has a higher HTHS than the M1 0W40 you are referring to at >3.7
this thread is 13 years old brotato
 
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