It Makes Sense that Start-Stop Engines Need a Higher Grade Oil

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If I owned a vehicle with start/stop engine technology, I would use a European synthetic 5W-30 oil with HTHS >= 3.5 with 4,000 mile oil change intervals regardless of what the owner's manual recommends. New engines can cost $10,000+. Would want to do everything I could to keep engine wear at zero so it could last 300,000 miles.

The European oils stay in grade (even with fuel dilution) and pass very strict anti-wear tests under very high temperature/high sheer condtions that American speced oils would fail.
 
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The European oils stay in grade (even with fuel dilution) and pass very strict anti-wear tests under very high temperature/high sheer condtions that American speced oils would fail.
Unfortunately, this is not true as a blanket statement. I owned two Mercedes (C300 and AMG GLC43) both with turbocharged DI engines and both of them could push a 0W-40 into the low xW-30 range in about 5K miles which was far less than MB recommended. Mobil 1 0W-40 handled dilution the worst, with Castrol Euro handling it the best and Pennzoil Euro somewhere in between.

MPI engines with S/S do not have an issue with dilution and thus the Euro oil as well as most others would hold viscosity. It is the engines which are prone to it that will suffer from dilution irrespective of the start/stop.
 
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I've long been a fan of Castrol Euro 5W-30 A3/B4, 5 quart jug available on Amazon and Walmart for about $31.

It's API SL, would be SN, but phosphorous is slightly higher than SN allows, but needed the extra phosphorus to pass the difficult European A3/B4 anti-wear tests. This would be my #1 choice for any engine that is very hard on the oil.
 
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I always wondered about the long term effects on oil with the start and stop feature. If I had that enhancement on my vehicles I would disable it if possible. My mom's old 99 Buick with 90,000 miles had some sludge from her running such short trips all the time even though the oil was clean with no start and stop feature of course. Those short trips are not good for an engine.
When I lived on the west side of Wichita my buddy who is a couple years older than me would take his mom's Chevy Beretta on the weekends and we drive all down the canal route, k42, K15, etc. From her apartment to Target was like 2 mi. That was the first time I heard somebody tell me that you have to get out and blow the crud out.
 

ZeeOSix

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The Prius has to be the ultimate example of a start/stop car. The engine gets shut down and restarted all the time when driving around town. Yet, you don't hear of oil issues related to that at all. 0w-20 with 10k changes and they usually last for just about forever.
10K on the odometer, but not 10K worth of driving by ICE on the oil.
 
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If I owned a vehicle with start/stop engine technology, I would use a European synthetic 5W-30 oil with HTHS >= 3.5 with 4,000 mile oil change intervals regardless of what the owner's manual recommends. New engines can cost $10,000+. Would want to do everything I could to keep engine wear at zero so it could last 300,000 miles.

The European oils stay in grade (even with fuel dilution) and pass very strict anti-wear tests under very high temperature/high sheer condtions that American speced oils would fail.
or you could just disable the (auto stop/start) system.
How many engines have you personally worn out?
 
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or you could just disable the (auto stop/start) system.
How many engines have you personally worn out?
It's not a question of "wearing out an engine".
Instead my concern would be excess wear caused by high temperature / high sheer conditions which can permanently sheer a 20 weight oil to a 16 weight or even lower viscosity after 4k miles. Over time, without enough film strength the excess wear can cause an engine that uses no oil in between oil changes to start consuming oil. I currently don't own a start/stop engine.

I currently own 2006/2007 Honda Odyssey EX-L's with the VCM1 (VCM1 didn't have the oil consumption defect that VCM2 on 2008 and newer Odysseys had). So I prefer not to muzzle the VCM1, so I can get the better gas mileage by driving about 40% of the time on only 3 cylinders. I drive with a light foot, I coast a lot, and I accelerate before hills so I can let the momentum carry me up a hill). After detailed discussions with Trav on this board years ago, it became evident that 20 weight oil (as recommended in the owner's manual) was not a good fit for the Honda J series 3.5 Liter V6 with VCM engines. Trav mentioned that as a mechanic, he saw a very common issue of varnish on the front 3 cylinder heads which get extra hot and also extensive sludge in the engines. Trav recommended using a thick 5W-30 or perhaps a 5W-40 as that was what that same engine is speced for in Europe. I also use Fram Ultra Synthetic oil filters, as they have an efficiency rating of 99%+ to remove the small oil particles which can cause engine wear which other filters miss.

My current oiI change strategy is to use Pennzoil Platinum High Mileage 5W-30 (with Viscosity @ 100C = 11.4), and HTHS approximately 3.1/3.2 with a 4k oil change interval. This has done a good job of treating the oil seals on my Odysseys, and none of them have any oil leaks at all. But, if I plan to do any severe driving like a long vacation that might include going up steep mountain hills for example, I'll use Castrol Euro 5W-30 A3/B4 oil (with Viscosity @ 100C = 12.1, and HTHS = 3.5). I also have an Audi, which only get's Castrol Euro 5W-30 A3/B4.

I'm not looking to start a thick versus thin debate, as I know both sides are happy with their choice for their own reasons and not looking to change any one's mind. I am different that most people, as I like to keep engine and transmission wear to the absolute minimum with a target of keeping each vehicle for 200k to 300k miles. I also do a drain/fill of my transmission fluid every year with Honda genuine transmission fluid.
 
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It's not a question of "wearing out an engine".
Instead my concern would be excess wear caused by high temperature / high sheer conditions which can permanently sheer a 20 weight oil to a 16 weight or even lower viscosity after 4k miles. Over time, the excess wear can cause an engine that uses no oil in between oil changes to start consuming oil.
What evidence do you have to suggest your statement that rapid wear begins when an engine is operated with a 16wt oil?

If true, this UOA should’ve been very different.

 
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What evidence do you have to suggest your statement that rapid wear begins when an engine is operated with a 16wt oil?

If true, this UOA should’ve been very different.

Not looking to start a debate here. If you google HTHS wear graph, you see the graph which shows exponential engine wear increase once HTHS goes below 2.6. 20 weight oil is HTHS = 2.6 when it is new, but sheers down to about HTHS=2.3 near the end of a 5k mile oil change interval. Of course fuel dilution would make that worse. OW-16 starts out at HTHS of 2.3, and can sheer to below 2.0. Engine wear can take many years to surface (like bearing or timing chain wear) as Ford's timing chain debacle when they switched to 5W-20 and later re-speced those cars to 5W-30 and doesn't necessarily show up in the $20 oil analysis tests. My opinion (and it's just my opinion) is that the Europeans got the oil specifications correct by requiring a HTHS of 3.5 or higher to pass ACEA A3/B4 and C3 specification. I know the entire oil industry in the US has gone thin due to CAFE. I personally believe following the viscosity recommendation and oil change interval in your new car owners manual is the best way to rapidly increase engine wear (like Toyota's 0W-16 viscosity with 10k oil change intervals for their new cars). By the time a 0W-16 oil sheers to a 0W-8 or 0W-4 during a 10k oil change interval, engine wear could be astronomical. Time will tell, after many years and 150k miles, if these engines are consuming 3 quarts of oil a month or not. Anyway, it's a free country, we can all use the oil viscosity and oil change interval we think is best for our engines. If you favor thin oils, you might be right based on the reasons you have.
 
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ZeeOSix

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Instead my concern would be excess wear caused by high temperature / high sheer conditions which can permanently sheer a 20 weight oil to a 16 weight or even lower viscosity after 4k miles. Over time, without enough film strength the excess wear can cause an engine that uses no oil in between oil changes to start consuming oil. I currently don't own a start/stop engine.
To add, there's a difference between oil film thickness (due to viscosity/HTHS/MOFT) and oil film strength (due to AF/AW additives). Permanent shearing and fuel dilution would effect the film thickness more than the film strength.
 
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To add, there's a difference between oil film thickness (due to viscosity/HTHS/MOFT) and oil film strength (due to AF/AW additives). Permanent shearing and fuel dilution would effect the film thickness more than the film strength.
Thanks. Your terminology is correct. Film thickness is what I intended to convey.
 
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My opinion (and it's just my opinion) is that the Europeans got the oil specifications correct by requiring a HTHS of 3.5 or higher to pass ACEA A3/B4 and C3 specification. I know the entire oil industry in the US has gone thin due to CAFE.
Not denying that many oil viscosity choices are influenced by CAFE. However, keep in mind that Euro's have largely moved away from the higher HTHS oils in recent years. VAG has gone to 508.00, BMW has gone to LL-17FE (and others), MB is a mixed bag.
 

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Not denying that many oil viscosity choices are influenced by CAFE. However, keep in mind that Euro's have largely moved away from the higher HTHS oils in recent years. VAG has gone to 508.00, BMW has gone to LL-17FE (and others), MB is a mixed bag.
It is interesting however that VW maintains 504 for the higher-output Golf R.
 
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...After all, we have found that the oils do not get fully warmed up especially for trips to the grocery store. Fuel in the oil will not get burned off.

Oil will get more fuel dilution as starting up engines will use extra fuel.

Fuel dilution and loss of grade would likely be more common. To maintain a safe grade for that particular engine one would need to start with a thicker one.

Dilution not only results in loss of viscosity but also the loss of the concentration of the additives in the oil.

Aside from all the other detrimental effects I feel these mandates are harmful to the engine and the environment overall.

ali
Is this a strawman?

BMW has used stop/start for over a decade. During this time BMW has moved from 30w/40w w/ min hths of 3.5 -->> 30w with hths of 2.9 - 3.5 -->> 20w with hths under 2.9

BMW does use a special coating on the bearings or crank (can't remember) with the move to 20w.
 
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