In one of you previous posts you mentioned how you like to rev your expensive engines when cold, you being unwilling to let them warm up first.
Scott
Start up wear, Normal wear, and the relation to various oil properties. SAE 2006-01-3414
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Scott
Observing my own car, letting it idle to warm up one morning, the coolant took ~11 minutes to reach 180°F. The oil was still just 115°F. As soon as I started driving, the oil temp rapidly came up to 180-200°F range.
The higher the base oil viscosity, the weaker the additive response. This is one reason why additive reactivity diminishes at colder temperatures, but it's also just a matter of chemistry. Heat drives chemical reactions.
When I break in a new engine, I heat the oil to at least 180°F before pouring it in the engine, priming the system, and starting it for the first time.
I see it way too often where guys run 160°F thermostats in their street driven car, with something like VR1 20W-50, and wonder why they're getting lifter and ring wear.
Water is another factor. Condensation from hot combustion and coolant causes the block to sweat, dumping moisture into the oil. The longer the oil stays cold, the worse it gets.
The higher the base oil viscosity, the weaker the additive response. This is one reason why additive reactivity diminishes at colder temperatures, but it's also just a matter of chemistry. Heat drives chemical reactions.
When I break in a new engine, I heat the oil to at least 180°F before pouring it in the engine, priming the system, and starting it for the first time.
I see it way too often where guys run 160°F thermostats in their street driven car, with something like VR1 20W-50, and wonder why they're getting lifter and ring wear.
Water is another factor. Condensation from hot combustion and coolant causes the block to sweat, dumping moisture into the oil. The longer the oil stays cold, the worse it gets.
They cooled the engine which put the engine into a high wear mode of operation? A just started engine and the warm up period always has higher wear than an engine at a stabilized operating tempertature. Thin oil and thick oil on startup . It would depend upon the starting temps at 0*f a straight 30 would most likely not be the best at pumping but a 5W-30 would pump fast. Everything is a compromise. Adding more anti wear materials for example will be better until there is too much antiwear materials. Thicker is better untill there is no more better.
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There are many people here who state that wear additives are not needed if the oil is thick enough, only when the oil is too thin and then boundary issues come into play. MOFT is the only thing that counts. The author says that ring wear is nil at steady states. Yet it is mostly boundary lubrication. Motor oil is a complex thing.
Ali
Ali
I've been on here just about as long as you have and I've never seen anyone state that, much less "many" poeple.
"They cooled the engine which put the engine into a high wear mode of operation?"
They took the hot oil out of the running hot engine, cooled it and ran it back into the engine at room temperature. Wear went up 10 fold. Hard to explain. Many think they understand this. I do not.
Ali
They took the hot oil out of the running hot engine, cooled it and ran it back into the engine at room temperature. Wear went up 10 fold. Hard to explain. Many think they understand this. I do not.
Ali
Yeah, it's not a typo. This was an older study, done before the lower grade labels were changed to 16, 12, 8, etc.
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No it's not. Perhaps you should contact Dr. Eric Schneider at GM again and seek his explanation.
OVERKILL
$100 Site Donor 2021
But that grade has never existed in J300.
I really do not waste my time worrying about these things because odds are other than a mechanical failure taking out an engine, engines usually out last the transmission , rust and the ownership of the vehicle.
I've been comparing the PDS sheets for 0W-20 recently because I bought a new vehicle with a 'dynamic force' (A25A-FXS) engine, and I was also comparing the 40° viscosity between 0W-16 and 0W-20.
0W-20 Kinematic Viscosity @ 40ºC, cSt lowest to highest
- Liqui Moly Special Tec LR 39.5
- Mobil 1 Truck & SUV 42
- Penzoil Platinum 43.4
- Mobil 1 AFE 43.54
- Valvoline Advanced 44
- Valvoline Extended Protection 44
- Castrol Ultraclean 44.09
- Liqui Moly Special Tec AA 44.5
- Mobil 1 EP 44.6
- Quaker State Full Synthetic 44.61
- Liqui Moly Molygen 45
- Castrol Edge Extended Performance 45.1
- Motul Hybrid 45.4
- Penzoil Full Synthetic 45.8
- Amsoil OE 46
- Castrol GTX 46
- HPL Passenger Premium 46.02
- Penzoil Ultra Platinum 46.3
- Amsoil Signature 47.1
- HPL Premium Plus 47.22
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Yup. It's why most wear occurs during warmup, not at startup. An engine should not be operating cold nor too hot but rather at the correct operating temperature.
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Wow, fresh oil hurts an engine.
Never heard that one before
Never heard that one before
Operation itself harms an engine, it’s just how much and for how long.
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Due to COVID parts allocation and some other bs, my truck didn’t come equipped with the female conduit for the block heater even though I paid 95$ for it to be installed at the factory.
I had 5w-40 in it and did a few cold cranks at -6 to -13 during that artic blast we had three weeks ago. I’ll cycle the preheater twice. It has an idle up feature that I can adjust but when it’s rly cold it will engage the VGT and idle up slightly at 1,000 rpm and In under 7 minutes the block will be ~150 degrees and oil temp is around 120.
I haven’t noticed or felt anything bad during those cold cranking mornings.
I’ve also cold cranked in that temperature in my 4.0 in-line 6 Jeep with 10w-30. What you don’t want to do is start it up and just WOT it to warm it up
I had 5w-40 in it and did a few cold cranks at -6 to -13 during that artic blast we had three weeks ago. I’ll cycle the preheater twice. It has an idle up feature that I can adjust but when it’s rly cold it will engage the VGT and idle up slightly at 1,000 rpm and In under 7 minutes the block will be ~150 degrees and oil temp is around 120.
I haven’t noticed or felt anything bad during those cold cranking mornings.
I’ve also cold cranked in that temperature in my 4.0 in-line 6 Jeep with 10w-30. What you don’t want to do is start it up and just WOT it to warm it up
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Although for me the real concern with diesels when it’s that cold is wet stacking
I parked and idled up at 1,450 rpm when the engine was at 186. It was -13 with 17 mph winds hitting my radiator. In less than three minutes the coolant temperature dropped from 186 to 172. And that’s idling up at 1,450 rpm.
I parked and idled up at 1,450 rpm when the engine was at 186. It was -13 with 17 mph winds hitting my radiator. In less than three minutes the coolant temperature dropped from 186 to 172. And that’s idling up at 1,450 rpm.
In a way it does, assuming the old oil is still in decent condition.
I wish i could find the study that talked about this right now but it's been a long time since i read it.
Each time you change the oil, the fresh oil washes away the microscopic tribofilm that was built up by the previous oil's antiwear additives, and that tribofilm has to build up again.
Basically in the study they mentioned that indeed wear is higher right after an oil change with new oil, and then gradually goes down and stabilizes, iirc they said on average it takes around 800 miles ( or was it km?? ) until that tribofilm is back to what it was before the oil change.
Ofcourse as i said this is assuming the old oil is still ok, in other words not completely fuel diluted, or thickened by oxidation, or with a completely depleted TBN.
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