Choosing Oil Weight Based on Actual Engine Temps

[FMC]

Maybe this has been covered at some point, but I will ask anyway.

Using a scanner plugged into my OBD port, I can pull up ECT Temps (engine coolant temp) It does not show specific Oil temps. This is a 2022 Nissan Pathfinder and has an factory oil cooler located at the oil filter, 3.5L V6

At 87*f ambient

A/C on cooling fans on continuously the ECT temp stays right at 195*, I was stuck in traffic at a standstill and never went above 195*

Same day, same traffic conditions but with A/C off, ECT temp would reach 210* and not go any higher, cooling fans would come on and temps would drop back to 197* and just cycle between 197* to 210*

So based off of this information, what oil weight would you choose 0W20 (factory spec) or 5W30 ?

My thinking is 0W20 is fine in this application.

 

[SC Maintenance]

Oil temps and Coolant temps aren't necessarily related. Even so your coolant temps look look pretty normal for most modern engines. It wouldn't be an input into my decision.

 

[NiwradND]

Use factory spec until warranty is over. If it works well continue to stick with it. If many miles down the road or it starts using a little oil jump up to 5w30 in the summer.

 

[FMC]

Oil temps and Coolant temps aren't necessarily related. Even so your coolant temps look look pretty normal for most modern engines. It wouldn't be an input into my decision.

I was thinking to add 20* to the ECT temp to get close to Oil Temps

Coolant 195* to 210*
Oil 215* to 230*

 

[atikovi]

Running temperature isn't as significant as cold cranking temperature. In Philadelphia, either will be fine although if you see many winter starts below 10°F, 0w20 would be a better choice in that season.

 

[ka9mnx]

Engine builders and vehicle manufacturers spec oil grade by main and rod bearing clearances not oil temperature. They have a pretty good idea of what oil temperature will be. Race engine builders add anticipated oil temperature into the equation.

 

[SC Maintenance]

Engine builders and vehicle manufacturers spec oil grade by main and rod bearing clearances

I have always struggled with this, given My Toyota specs anything from 0w-16 to 15w-40 depending on what part of the world you bought your car, even though its a global engine with the same bottom end.

Other vehicles I have researched have similar discrepancies. Possibly the OEM's specifically, but possibly engine builders, have multiple priorities - like MPG or HP at the output shaft, vs simply engine longevity?

 

[twX]

I've got an oil-to-coolant heat exchanger on my car, as well as an oil temperature gauge. After engine warmup, coolant temperature will be maintainted at 88-91 C in ambient conditions from -35 C to +35 C. In the very cold weather, oil temperature will struggle to get much past 80 C, even with the heat exchanger helping to warm it up. In very hot weather, oil temperatures will hit 100 C in normal driving, and potentially hotter in hard driving. The heat exchanger helps to reduce maximum oil temperatures, but they're not regulated extremely effectively. That said, oil coolers are great since they allow for the use of thinner grades of oils without sacrificing engine protection in hot engine operation. A reduction in maximum oil temperature of only 7 C will allow the oil to be about one grade thinner without sacrificing engine protection.

Unless you suspect that your oil is getting unusually hot, I would follow the manufacturer's recommendation. Thicker oil should really only provide a benefit for those outliers with unusually hot oil temperature (from racing, towing, extreme hot weather, cooling system problems, etc.)

 

[NiwradND]

I was thinking to add 20* to the ECT temp to get close to Oil Temps

Coolant 195* to 210*
Oil 215* to 230*

My vehicles run lower oil temps than coolant temps

 

[Titan]

You still don't know the oil temps in various parts of the engine. I'd say do what the manual states, including bumping it up a bit if you haul/tow. Even without such a manual recommendation, you won't hurt anything (and MAY help) to bump up a bit, especially if you do haul/tow.

 

[Greasymechtech]

I'd go thicker with a full synthetic 5w30, higher hths 5w30, or even 0w40

I'd even consider adjusting my intervals, both oil and coolant, to keep it healthy

Does your scan tool offer the oil temps?

Protect your engine or being green... you don't get both!


Nissan up to a 10k mile oil interval like some other brands?

 

[FMC]

I'd go thicker with a full synthetic 5w30, higher hths 5w30, or even 0w40

I'd even consider adjusting my intervals, both oil and coolant, to keep it healthy

Does your scan tool offer the oil temps?

Protect your engine or being green... you don't get both!


Nissan up to a 10k mile oil interval like some other brands?

Nissan recommends 10K interval, I do 4K every 4months, I average 12K miles per year. I use Mobil 1 EP 0W20, but may consider Mobil 1 5W30 or Castrol Edge EP 5W30

The viscosity of the Mobil 1 0W20 @ 100*c is 8.8, the 5W30 is 10.1 so not that big of a difference but maybe the 5W30 might offer a slight advantage . Castrol Edge EP 5W30 @ 100*c is 9.9

Scan tool does NOT read oil temp.

 

[weaponoffreedom]

Maybe this has been covered at some point, but I will ask anyway.

Using a scanner plugged into my OBD port, I can pull up ECT Temps (engine coolant temp) It does not show specific Oil temps. This is a 2022 Nissan Pathfinder and has an factory oil cooler located at the oil filter, 3.5L V6

At 87*f ambient

A/C on cooling fans on continuously the ECT temp stays right at 195*, I was stuck in traffic at a standstill and never went above 195*

Same day, same traffic conditions but with A/C off, ECT temp would reach 210* and not go any higher, cooling fans would come on and temps would drop back to 197* and just cycle between 197* to 210*

So based off of this information, what oil weight would you choose 0W20 (factory spec) or 5W30 ?

My thinking is 0W20 is fine in this application.

I think that the 0w20 is for fuel economy not protection. Is 0w20 fine, sure at least for the life of the engine.