Synthetic oil makes your engine run 10-30* cooler

[Merkava_4]

Quote:
Synthetics do a much better job of “cooling” engine components during operation. Because of their unique flow characteristics, engine components are likely to run 10-30° cooler than with petroleum oils. This is important, because the hotter the components in your engine get, the more quickly they break down.


LINK

Interesting. I didn't know that.

 

[sasha]

makes me want to purchase an oil cooler to an additional trans cooler. some good points in the article. find the highest flash point oil with the best calcium add pack and your set.

 

[Shannow]

You didn't know that because it's not true.

A lower viscosity will mean a lower frictional loss in a bearing, and a lower temperature rise (note lower frictional loss does NOT mean less wear).

However, that's only if the synthetic has a lower operational viscosity than the dino it replaces.

Both the same viscosity, both the same temperature rise due to work against the oil, statement is false.

 

[NHGUY]

My Scangage II proves that PU runs just as hot as ST conventional.It didnt miracluously lose 10 degrees.

 

[Shannow]

The title of the post, the last post, and the linked "article" are thinking different things.

Article states "engine components".

If the lubricant has lower internal friction, the bearing and journal either side of it will be running cooler...

 

[edwardh1]

I thought cars had thermostats

 

[Mr_Incredible]

I noticed a pretty big temp drop when I started using M1 in the Harley. Around 15* IIRC. I was pleased.

 

[Hokiefyd]

The article makes this incorrect statement:

Quote:
Most petroleum oils have TBNs around 5.


The date on the article is 2013. I wonder what petroleum oils they're including in "most" here.

 

[jake88]

I'd like to see sources for claims like (1) flash point correlates with oil consumption, (2) that synthetic oils just innately have higher TBNs than petroleum oils.

And the author seems to not understand that almost all "synthetic" engine oils are in fact, not created in a lab and are made from Group III base oil.

 

[yesthatsteve]

Originally Posted By: Hokiefyd
The article makes this incorrect statement:

Quote:
Most petroleum oils have TBNs around 5.


The date on the article is 2013. I wonder what petroleum oils they're including in "most" here.


Exactly. Going by PQIA's testing, most conventional oils have a TBN closer to 8

 

[FZ1]

Interesting,thanks. I can believe a 15* drop in temp,but 30*,as stated in the article, seems too much. Jmo.

 

[SLCraig]

Originally Posted By: edwardh1
I thought cars had thermostats


Coolant temp is not indicative of engine oil temp though.
There is some correlation, but it's no rule.

 

[dparm]

Originally Posted By: edwardh1
I thought cars had thermostats



Exactly. Modern vehicles are water-cooled, not oil-cooled. That's why we can run 5w30 year-round, even when towing a boat in Death Valley.

 

[meep]

1. they are talking about components--- rods and pistons are 400F +, up to 600F IIRC from old data.

2. the previous articles I've read on this is NOT based on friction-related heat properties. It's based on the oil's ability to conduct heat. earlier syn articles I've read where they instrumented running components illustrated that syn oil conducts heat better, and therefore "carries" it away from hot components better. This confuses a TON of people. why? Certain components are cooler (the hot ones). Certain components then get hotter! like the cooler ones that the oil sheds its heat to. The oil temp will then vary more based on where it is in the engine, so measuring oil temp alone is useless.

too much data for the average backyard DIY to accurately test/validate/or even fully understand without really looking into it.

 

[Ken2]

There is no such thing as "engine temperature." There is the temperature at many points within an engine, and these vary according to speed and load. A very large diesel, for example, will have sensors in the oil at each main bearing and catch pans for the oil thrown from each conn rod bearing, as well as the oil from each crosshead bearing (wrist pin bearing). It will measure the temperature from the oil or water that is cooling the inside of each piston. It will measure the temperature of the water from each cylinder head. And, of course, the inlet and outlet temperatures of the oil coolers and water cooler, plus the charge air temperature exiting the turbochargers and exiting the intercoolers.

A car engine will have a temperature sensor in the coolant in the head. It may have one in the transmission fluid even it if isn't displayed. It may have a sensor in the oil sump. This is missing a lot of temperature points within the engine. As noted above, oil temperatures can reach very high points, but for very short time periods. What kills oil is time-at-temperature. 400°F for a fraction of a second doesn't cook the oil. 400 for several seconds will cook the oil.

The synthetic oil running cooler thing seems to be a cure looking for a disease. We aren't having failures due to conventional oil running hot. If one is racing or towing hot & heavy, maybe...otherwise, it is just one more thing to not worry about.

 

[y_p_w]

Originally Posted By: meep
1. they are talking about components--- rods and pistons are 400F +, up to 600F IIRC from old data.

2. the previous articles I've read on this is NOT based on friction-related heat properties. It's based on the oil's ability to conduct heat. earlier syn articles I've read where they instrumented running components illustrated that syn oil conducts heat better, and therefore "carries" it away from hot components better. This confuses a TON of people. why? Certain components are cooler (the hot ones). Certain components then get hotter! like the cooler ones that the oil sheds its heat to. The oil temp will then vary more based on where it is in the engine, so measuring oil temp alone is useless.

too much data for the average backyard DIY to accurately test/validate/or even fully understand without really looking into it.

I believe at one point the PAO/ester blended oils had a higher "specific heat" and were better at drawing away heat through the oil pan and other components. Even though coolant does most of the cooling, there's a substantial amount of cooling from heat carried away by the oil.

By the same token, a higher proportion of water in the coolant mixture cools better, because water has a higher specific heat than glycols. I've seen some manufacturer's charts indicating that as low as 37% of their uncut coolant was enough for adequate corrosion protection (i.e. the additives) as long as the car never saw subzero (F) temps.

http://www.engineeringtoolbox.com/specific-heat-fluids-d_151.html

Quote:
Ethylene glycol 2.36 kJ/kg.K
Water, fresh 4.19 kJ/kg.K

 

[webfors]

I think this is along the lines of the MPG increase claimed by some with syn.

There are two benefits of syn IMO;

1. They last longer in service before self destructing.
2. They tend to have better cleaning abilities.

 

[Errtt]

Originally Posted By: Mr_Incredible
I noticed a pretty big temp drop when I started using M1 in the Harley. Around 15* IIRC. I was pleased.


When I changed from Harley's conventional 20w-50 to Amsoil synthetic 20w-50, my oil temp gauge also dropped. So there has to be something to this.

 

[CATERHAM]

The main advantage of synthetic oils is their superior extreme cold start performance, higher viscosity index, greater oxidative stability at high temp's and they keep engines cleaner internally along with lower intake and piston deposits.

 

[CATERHAM]

Originally Posted By: Shannow
You didn't know that because it's not true.

A lower viscosity will mean a lower frictional loss in a bearing, and a lower temperature rise (note lower frictional loss does NOT mean less wear).

However, that's only if the synthetic has a lower operational viscosity than the conventional it replaces.

Both the same viscosity, both the same temperature rise due to work against the oil, statement is false.

Right it's not true.
Even when one is comparing two oils of the same grade, the conventional oil will usually have a higher operational viscosity since it has a lower VI. And if that means the conventional oil is operating with the oil pump still in by-pass mode and the lighter synthetic oil is not, for sure the oil temp's will be lower due to the less restricted oil flow with the synthetic oil.