The Danger of Increasing Viscosity

[BlazerLT]

quote:

---

Originally posted by GoldenRod:

quote:

---

GoldenRod - I read the thread again and didn't see your car/engine. Probably missed it badly Am I guessing you have the ecotec too?

---

It's 3800V6 in a little Buick. I'm not worried about the increase in oil pressure, although I am surprised by the amount of increase.

---

Would a reduction in fuel economy be worth it?

Go with a thicker 30 weight if you want, but there will be no benefits of going to a thicker oil in the engine.

 

[OriginHacker21]

I'll probably stick with a heavy 30 weight - Amsoil 5w30 HDD and GC 0w30... I'd be more interested in the UOA

 

[mechtech]

CBD - There is oil induced drag in many places besides the crank mashing through the oil in the pan.

 

[sprintman]

You could run 25W70 without any trouble as I did for many years in my Mazda 626 turbo (GT) which specs 5W30 in the U.S. As I've said many times Americans suffer from viscosity phobia. The figures might go up but the oil isn't that much thicker in reality when you pour it. Get over it!

 

[BlazerLT]

quote:

---

Originally posted by sprintman:
You could run 25W70 without any trouble as I did for many years in my Mazda 626 turbo (GT) which specs 5W30 in the U.S. As I've said many times Americans suffer from viscosity phobia. The figures might go up but the oil isn't that much thicker in reality when you pour it. Get over it!

---

You know why, because some of us suffer from freezing temperatures for half of the year.

And putting an engine through oil starvation based on your example is plain out ridiculous.

 

[427Z06]

quote:

---

Originally posted by sprintman:
You could run 25W70 without any trouble as I did for many years in my Mazda 626 turbo (GT) which specs 5W30 in the U.S.

---

And if you had an oil temp gauge, I bet the oil ran 20 degrees hotter turning it effectively into a SAE 40.

 

[i]

quote:

---

Originally posted by Titan:
And, no, this is not related to "blood thinners"...I wish EVERYONE would quit using that incorrect terminology...people are not on "blood thinners", they are on anticoagulants.

---

Yes, but the PATIENTS have some idea of what blood thinners are -- and the doctors know what you are talking about, so who cares?

There's so much unintuitive/completely wrong terminology (left over for historical reasons) in medicine anyway, I can't see why some folks freak out about a select few terms.

 

[sprintman]

BlazerLT it frezzing herewhere I live for months. I ran 25W70 for many years and the engine has 240,000kms on it untouched and runs better than it did when I bought it. You know if you put every available viscosity oil between 0W20 and 40W70 in unmarked botles and asked people to pour some and guess it's viscosity there isn't anybody on BITOG who would get them all right, me included. they just dont vary in reality much at all.

 

[Ramblin Fever]

quote:

---

Originally posted by sprintman:
they just dont vary in reality much at all.

---

They do when they're hot. I can tell you when a 5w-30 versus a 10w-30 comes out of my truck when it's hot. The 5w-30 literally looks like water.

And there IS a room temp visibility difference, that I can see, from Delo 15w-40 versus Motorcraft 5w-20 or even 5w-30.

The ONLY thing I would dream of running a 15w-40 or higher in year-round, would be my diesel OHV engine - that's cause it sits on a block heater when it's real cold out.

I am running 15w-40 in my 22RE Toyota for the summer, but will switch back to 10w-30 for winter.

My other high mileage DD's getting 5w-30 for winter, and an experimenting mixture of 2qts 5w-20 & 3 1/2 qts of 15w-40 for summer. Have no idea what that equates to, but it likes it.

 

[bar1]

quote:

---

Originally posted by OriginHacker21:
I'll probably stick with a heavy 30 weight - Amsoil 5w30 HDD and GC 0w30... I'd be more interested in the UOA

---

You can use M1 0W-40 if you want to use a 40 weight. That oil has the correct GM LL... specs. for your Ecotec engine.

 

[dailydriver]

quote:

---

Originally posted by Titan:
Oil is the "blood" of an engine. Viscosity is like the hematocrit. Too thin, and the heart has to be able to pump a little more per minute to keep up with the tissue requirements (but, that's not hard to do when the resistance is decreased with thinner fluid to pump). Too thick, and the heart has to pump HARDER to overcome the viscosity-induced drag, which takes more energy input. PLUS, the smallest capillaries may be underperfused, and sludged. Yep, that is the term used...it isn't sludge like oil sludge, but, it is areas of decreased/no flow. Athletes, blood doping, and the problems it creates are good examples of what can go wrong with having fluids too thick.

Below operating temps, oil is too viscous. This slow-flowing, too-thick oil is what is causing the increased wear at startup, and for the first 10-15 minutes of operation. TOO thick is obviously bad. What constitutes too thick, depends upon other things besides temperature. If you have an older engine with a bit of crud built up in some of the oil passageways, your engine might run cooler/better with THINNER oil, because thinner oil can squeeze through the narrow passageway better than thick oil (we use that information in medicine to provide better blood flow past narrowed arteries...you want the blood less viscous in order to perfuse the areas past the narrowing. And, no, this is not related to "blood thinners"...I wish EVERYONE would quit using that incorrect terminology...people are not on "blood thinners", they are on anticoagulants. Completely different subject.)

Anyway, I think there are very good reasons to steer away from using oil that might be too thick: and remember, they are ALL too thick at startup.

---

Pretty good analogies there.
I remember the stir/alarm that the EPO abusers caused some years ago. Several junior/espoir ( under 21 yrs. of age) cyclists were actually dying in their sleep of massive coronary failure. These were some of the most fit, young endurance athletes on the planet, so something was suspect. Turns out they were doping with a synthetic form of the naturally occurring EPO, to the point that their hematocrit levels were so high that their blood literally became too thick to pump and overwhelmed their very strong hearts!

I wonder, at what point does this same thing happen happen to an engine's oil pump? 150W? 200W or more??