Changed the oil. Interesting observation.

 There have been some incredible things to come from modern chemistry with a lot of these newer synthetic oils. They can last a very long time that most new car oil change intervals are now 10k miles and the UOA that I have seen are incredible. However this might not be the case for performance cars because the oil can still go bad earlier because of fuel dilution if you are running rich.  Newer engines demand better oil but for a car like ours this new stuff will make our engine last longer especially if you have years of built up deposit formation that will get cleaned out.  It will be interesting to see how these newer 0W-16 oils do. 

 It is interesting to know that Briggs and Stratton for the last few years  recommends that the owner doesn't change the oil, only add make up oil when using synthetic for the life of the motor for small lawnmowers and other equipment. 

Posted by: @ispy

Thanks. 

I found a great article that explains it better than I can with a bit of history thrown in. 

https://bestsyntheticoilguide.com/synthetic/viscosity/

 Keep in mind that they may mention that thiner oils do not offer protection which is true if you use it in an engine that requires a thicker oil. If the engine is designed to run a thiner oil it should be fine as the engine design with tighter tolerances has made thinner and thinner oils a reality. They think the future of newer oils will be headed towards  0W-10.

This layman would think that thicker oil than spec would cause all sorts of issues, particularly with hydrodynamic bearings, primarily from heat, I would guess, since you're simlply increasing drag, the whole engine load increases, and so on.

Too thin just means friction between solid surfaces as opposed to the friction netween molecules in a too-viscous liquid.

Posted by: @nottamiata

This layman would think that thicker oil than spec would cause all sorts of issues, particularly with hydrodynamic bearings, primarily from heat, I would guess, since you're simlply increasing drag, the whole engine load increases, and so on.

Too thin just means friction between solid surfaces as opposed to the friction netween molecules in a too-viscous liquid.

Yes that is correct and there or other factors like incentives to increase energy efficiency at the expense of the longevity of your engine.  Manufactures at one time we’re using too thin of oil to improve their CAFE ratings so they can sell SUVs in their line up. Later on they were able to improve the 5W-20 oils with better formulation.  Then manufactures decided to use lower tension piston rings with thin oil and it was a disaster of oil consuming engines like what happened with Subaru. 
Going too thick like a 50wt oil is not a good idea but a thin 40wt oil is perfect for performance use as the drawbacks of going slightly thicker are not seen on used oil analysts and there is a good possibility the wear numbers might be lower. The only drawback could be a mile or two less per gallon of fuel. 

@dev  You have to remember that every automotive engine that has gone into production has passed that manufacturer's General Durability Test cycle using the factory-fill oil (or equivalent).  This is a 400 to 1000 hour test (depending on which OEM) that continually cycles between full-power, peak torque, and idle.  At the end of the test the engines are torn-down and inspected.  So there is no need to fear that the spec-oil viscosity is too thin, unless you modify the engine for significantly more power.

Posted by: @dblotii

@dev  You have to remember that every automotive engine that has gone into production has passed that manufacturer's General Durability Test cycle using the factory-fill oil (or equivalent).  This is a 400 to 1000 hour test (depending on which OEM) that continually cycles between full-power, peak torque, and idle.  At the end of the test the engines are torn-down and inspected.  So there is no need to fear that the spec-oil viscosity is too thin, unless you modify the engine for significantly more power.

I want to use an oil that has lower wear numbers for the kind of conditions and performance driving that I do than to have the manufacturer recommendations  for normal commuter use for efficiency recommendations. I also want an engine oil that is the best for the money. This means that I will not entertain boutique oil but certainly not some off brand at Walmart even if it has the approval. My choice for my car is based on what Lotus recommends for the same engine which is what they found though extensive testing. Although this is more to with how the car is being used I personally have found lower evaporation losses using the 40wt oil when its run hard which keeps my make up oil during the interval in check. I have decided that since Im hard on the engine it would be in my best interest to error on the side of protection with virtually no downsides.

 As far as other cars I always follow the manufactures recommendations and don't error on thicker is better. My other two cars use  0w-20 and I have no problem with it but many enthusiast do and therefore they run ticker oil which I do think is wrong. As long as the UOA comes back great that all that matters to me. 

I just wanted to update this with a report of some success with the change to SRT oil. 

 My 2ZZ doesn't burn any oil if you drive it normally but it will burn a little if you go into lift a lot and drive it hot. Most cars that are performance driven do also burn a little oil when driven hard and some more than others as that is just what engines do. Some of this is blow by gases mixed with oil vapor and some of it gets evaporated during high revs.  One of the many reasons I switched to this oil is for its low volatility formulation compared to the Euro Castrol and it's actually working. I have been going into lift a good bit since the oil change and by this time it would show 3/4s on the dip stick which would require a 1/4 of a quart make up oil. When I used  Motul engine oil it was much worse. Mobil 1 was no better. 

With the SRT oil it didn't happen.  This oil was designed for the SRT engine and those cars are notorious for being driven hard and require an oil that has low evaporation losses. Very impressed with this oil for the 2ZZ. 

My 2¢: I always change the oil warm. It's just what I've always been taught to do, although it does make sense that a fuller sump would yield a larger drain. If I'm being really thorough I will drain the oil warm, and then let the car sit overnight (continuing to drain) before completing the oil change in the morning. I actually think this is the best of both worlds, but I've only done it a few times because it is logistically a bit more complicated. I'm fortunate enough to have more than one vehicle to drive at the moment, so that makes it a little easier.

I must confess to very rarely pre-filling the oil filter, but I don't really feel bad about it. It's an extra step, it's potentially messy, and I have a hard time believing it makes a significant difference one way or the other in the long run.

I change it warm, and let it sit for an hour or so before putting the plug back in.  Never has the tiny amount of oil still left in the car from the previous oil change caused a problem in any vehicle I've owned.

@bimmer-bob    Next time you complete an oil change, have someone else start the engine while you listen with your ear close to the engine.  You will clearly hear the sound change (get quieter) after the filter fills.  

Posted by: @dblotii

@bimmer-bob    Next time you complete an oil change, have someone else start the engine while you listen with your ear close to the engine.  You will clearly hear the sound change (get quieter) after the filter fills.  

And if you really want to get technical with it, try to time how long it makes that noise, or how long the oil light is on. A few thousand miles later on the next oil change prefill your filter at least two times and repeat the whole process. You will come out knowing the engine has oil pressure much sooner. 

It's not messy if you take your time. 🙂

Posted by: @marsrock7

Posted by: @dblotii

@bimmer-bob    Next time you complete an oil change, have someone else start the engine while you listen with your ear close to the engine.  You will clearly hear the sound change (get quieter) after the filter fills.  

And if you really want to get technical with it, try to time how long it makes that noise, or how long the oil light is on. A few thousand miles later on the next oil change prefill your filter at least two times and repeat the whole process. You will come out knowing the engine has oil pressure much sooner. 

It's not messy if you take your time. 🙂

Alright, you guys inspired me to take the extra step next time, lol.

While the oil is draining I prefill my filter 3x. It all soaks into the media and there is hardly any visible in the filter when I install it. I don't spill a drop while putting the filter on (even in my TSX where the filter is horizontal). It's definitely not a necessity but I like that the engine runs for significantly less time without oil pressure.