0w-20 oil -- need to warm it up before oil change?

Speaking for myself, it's the double cleanup that I'm determined to eliminate.

I just don't see enough of a difference between a 5-minute dripout and a 2 hour dripout.

 

I don’t bother cleaning up.

seriously, I don’t always do it that way, but it’s an option, and it allows things to cool down.

 

For contrast, I do believe in a hot run before long-draining my small engines. They use thicker oil, they don't have filters, and the last little heel in there represents a much larger fraction of the total oil volume.

 

In grand scheme, it doesn't matter much if the oil is cold or hot. In the past, I've tried to do it while hot, but just do it whenever it is convenient.

From the link, "...soot causes oil to turn black...Since soot particles..."
Hot spots in the engine can also lead to scorched oil particles forming.

Other darkening is from oxidation, which is a big reason for changes to the additives and base oil.
"Polycondensation and polymerization (o) of the oxygenated compounds describe the effects of the final stages of oxidation. The increase in weight of the molecular compounds translates to the formation of sludge, varnish and deposits.

Not only do these insoluble products form, but organic acids corrosively attack the surfaces along with water. Most of the additives are also negatively affected and in turn become part of the deposit agglomeration. As aldehydes and ketones increase in the lubricant due to the condensation reactions, the apparent viscosity will begin to increase.

Insoluble, oxidized oil products (p) like sludge and deposits are significantly different from the oil molecules that make up the majority of the lubricant. Sludge is the buildup of insolubles, while deposits are insolubles that attach tightly to metal surfaces."
Identifying the Stages of Oil Oxidation | Machinery Lubrication

Insoluble = Particle
Particles do not have to be a hard, solid material. They can be softer, and even gel-like.
Part of the additive package in motor oil is detergents. These break up the heavier weight oxidation products, and keep them in suspension. That way, those particles don't become sludge or varnish. They can be taken out of solution by the oil filter.

Which is what I saw in the HHR. Started doing an oil change by replacing the top mounted oil filter. Then the the weather turned. So put off the actual oil change. Which didn't happen until a week later, with 300 more miles on the oil. The oil went from the dark usually seen before changing the oil to a light brown.

Oil filters don't 'bleach' the oil, they take solids out of suspension. The aging process oil goes through during use results in the formation of solids. That is why lubricants that aren't exposed to combustion products can also pass through a filter during operation.

Seems more important to have the oil cap open during the drain. Oil being thick no matter the viscosity rating, breaking the vacuum at the top of the engine will help with the fluid still up in the channels to get to the sump.

 

But according to you, the filter only works for the first 1000 miles or so.

I repeat that both of those statements are BS.
The oil "darkens" because of heat.
It turns BLACK usually because of soot......but not always.

Rant on. But your mis-statements are still wrong.

 

Which is a number I once heard. Could be wrong, but that wouldn't change the fact that filter clogs up over time, leaving more particles flowing with the oil. The majority of these particles come from the breakdown of the oil itself. They are abrasive like metal particles, so aren't a threat there. They can come out of solution to form varnishes, or clump up to make sludge. Which is why motor oils have detergents. With water, they, and the soluble oxidation products, can also form acids and cause corrosion.

"Oxidation is the most predominant reaction of a lubricant in service. It is responsible for numerous lubricant problems - including viscosity increase, varnish, sludge and sediment formation, additive depletion, base oil breakdown, filter plugging, loss in foam control, acid number (AN) increase, rust formation and corrosion."
Oxidation - The Lubricant's Nemesis

Heat alone can cause some chemical changes, but it is mostly speeding up oxidation reactions in the oil.

Writing more than calling BS isn't ranting.

 

You couldn't be more wrong if you tried.
You need to just give it up and move on.

A filter actually does a better job as it traps particles that it was designed to catch.
And that does NOT "leave more particles flowing".

It is, in fact a rare instance for a filter bypass valve to operate.
It just NEVER happens in normal use.

After 100,000 miles without an oil change......maybe.
If you throw a handful of sand in the crankcase......maybe.
IF the engine has already completely failed and there are chunks of metal trying to move around..............

What satisfaction do you get from shoveling crap that you make up ??

 

Not engine oil but I do like to drive my Tundra in 4x4 (4 High) for a bit before changing out the front differential and transaxle grease. (75W90 is pretty thick)
It also helps to have the car warm (not hot or cold) whenever swapping out spark plugs, too.

 

Anyone ever seen the dealer, or Pep Boys, or Big O or others - warm up your car after it's sits 3 or 4 or more hours before they get around to changing it? Yeah warming up is nice, but in the grander scheme, a few little leftover dribbles is far from Fatal. But often, just moving the car into the staging area does it somewhat - so it's kind of warmed anyway.

 

Many oil filter boxes listed the filter's single pass efficiency; a simple measure of how many particles of a given size are caught by the filter. It is never 100%. So some particles are getting through the filter media.

Oil filters are dead end filters. As they trap particles, the available filter media the oil can flow through shrinks. This leads to a pressure differential that can open the bypass valve.

If the filters did catch everything, and the bypass valve never opened, old oil would be as clear as new out of the bottle.

They can regularly open on cold starts.

 

Define "cold" ?
-40 F maybe ??

Another ridiculous claim for something which you have NO way of knowing.

 

I see you no longer try to counter my claims about the particles.

 

I keep coming back to something I read, about liquid med’s: some say shake before using, others don’t. The writer proposed: shake ‘em all, just to be sure they’re homogenized.

Sure for pros they’re not going to take your car for a protracted ‘round-the-block; time is money. And it could be argued the car still is semi-warmed, from customer’s drive over, and that short drive from the lot to the service bay is suffice, to stir it up.

But DIY, why not do your oil change right after a drive? Typically it’s not onerous; just takes a bit of timing.

 

Well, I follow what the manufacturer says to do. If Subaru maintenance manual says do it while the oil is hot, then follow. If not then it's up to you. I usually prefer hot/warmed up some on our Prius even though Toyota does not specify.

I'll give an example:. We have a Mercedes E63 M157 engine. I have to get the engine above a certain temperature and then I rush to drain the oil. Why? As the manual explains the oil cooler thermostat opens at a set temperature and in order to drain out all the oil and NOT overfill when refilling I have to be mindful of that temperature.

Follow what the manufacturer prescribes. (Of all the vehicle manufacturers' cars I work on about 50% hot and 50% no mention/not necessary).

BTW-

The oil is thinner viscosity wise when HOT, even the multi-weight. It has the viscosity of 20W when hot but that is still thinner than 0W at 0 degrees. Can verify on the information sheets.


Oil darkening can happen if I pour it in a pot and cook it long enough and/or at high enough temperature. Not necessarily from particulate matter which I would hope the filter takes care of.

moto g(7) power ?

 

Some people deliberately go against manufacturer's recommendations because they believe the manufacturers want our cars to fail, so we can buy new ones. This seems to be especially true when it comes to oil changes.

 

That's the oxidization reaction taking place. That reaction chain will lead to high molecular weight hydrocarbons that are no longer soluble in the oil. They aren't what most people picture as a particle because they didn't start as a solid, and may not be an actual solid, but that is what they are. The filter will catch some. Physically they are a serious threat to the engine, unless they clump up into sludge or varnish, but they could form acids. That can happen even with the ones trapped in the filter, and the acid will get into the oil.

Let that pot of oil get hot enough, and the oil will start scorching. Which can happen at engine hot stops.

 

lexus recommendations - use oem cabin filter. Thus - the better ½ got charged nearly $100 for their oem & 'labor' (20 seconds to remove wrapper, open filter door, slide old out slide new in & button it up). Amazon? $8.95
Just because the dealer recommends you do it? It doesn't mean it's the best or only choice.
.

 

Service procedure is different than parts recommendation. I prefer aftermarket parts personally. In this case it's a Subaru (I'm guessing with a turbo). Does it have an oil cooler? Does that have a thermostat that opens above a certain temp? Will all the oil drain properly?....

moto g(7) power ?

 

Interestingly Fram (definitely a controversial filter manufacturer) makes a cabin filter with N95 mask material. (Saw it at a local Walmart over the weekend). I wish I hadn't already purchased replacement Fresh Breeze filters that I kept for future use....

moto g(7) power ?

 

A couple of manufacturer's perspesctives. First, excerpt from 2006 Honda Civic Owner's Manual (yes, they have oil change instruction in Owner's Manual):



And from 2010 Toyota Prius Repair Manual (nothing in Owner's Manual), nada: