Mobil 1 Extended Performance 0W20 vs All 0W40's

[Shannow]

Originally Posted By: A_Harman
I wouldn't use 0w20 in an engine specifying 40-weight, but I would use it in an engine specifying 5w20.


Originally Posted By: buster
I wouldn't use a 0w20 in a 0w40 application.


Listen to these two...

Originally Posted By: daves87rs
Originally Posted By: badtlc
Sure you saw AEHaas run 0W20 in his Ferrari or Lambo. UOA was good.


Agreed. Thinking depending on the engine-you would be fine....


Not these two...

That was a really high power engine, designed for high speed and track use, with oil specified for those uses, and a heap of thermal management systems.

The 20 was installed, and the engine never used to a significant part of it's potential.

If he used the 20 on the autobahn, or a number of 3-4 hour sessions on the track, the argument would hold water, but he didn't so it doesn't.

 

[Shannow]

Originally Posted By: tig1
Even though I used Mobil 1 5w20 in the late 70s in an engine calling for 10-40 with success, there is no reason to use it today with all the various options we have.


Truth is that we don't KNOW what that oil was back in the day.

Given that pre-dates the use of high shear viscometry, we can't say for certain that the oil is the same as a 5W20 of today.

The 20W20s that people point to being specced for engines in the 60s would be labelled "really a 30" by a couple on the board, as they naturally have an HTHS of 2.9, which is the minimum for 30...they call Redline 20s "really 30s", farcical as it is.

My hunch (and I have no proof) is that back in the day, the flagship would have been more like Redline, and had a fairly high HTHS compared to the grades today.

 

[HTSS_TR]

Originally Posted By: Shannow
Listen to these two...

Originally Posted By: daves87rs
Originally Posted By: badtlc
Sure you saw AEHaas run 0W20 in his Ferrari or Lambo. UOA was good.


Agreed. Thinking depending on the engine-you would be fine....


Not these two...

That was a really high power engine, designed for high speed and track use, with oil specified for those uses, and a heap of thermal management systems.

The 20 was installed, and the engine never used to a significant part of it's potential.

If he used the 20 on the autobahn, or a number of 3-4 hour sessions on the track, the argument would hold water, but he didn't so it doesn't.

I agree.

It depends on how the vehicle is used.

The oil spec'ed is usually for the maximum performance of the engine and how the car should be used. But someone use it less than 20-30% of its potential 100% of the time then a much thinner oil can used without detriments.

 

[tig1]

Originally Posted By: Shannow
Originally Posted By: tig1
Even though I used Mobil 1 5w20 in the late 70s in an engine calling for 10-40 with success, there is no reason to use it today with all the various options we have.


Truth is that we don't KNOW what that oil was back in the day.

Given that pre-dates the use of high shear viscometry, we can't say for certain that the oil is the same as a 5W20 of today.

The 20W20s that people point to being specced for engines in the 60s would be labelled "really a 30" by a couple on the board, as they naturally have an HTHS of 2.9, which is the minimum for 30...they call Redline 20s "really 30s", farcical as it is.

My hunch (and I have no proof) is that back in the day, the flagship would have been more like Redline, and had a fairly high HTHS compared to the grades today.


Actually, I was using Valvoline 10-40 at the time(1978 and before). I was living in Maine(Very cold) then had terrible engine noise on sub zero starts. Upon changing to Mobil 1 5w20 all cold start engine noise stopped. Also I noticed the engine cranked over Much easier with the Mobil 1 5w20. What the numbers were wasn't important to me. What was important was the vast difference between the two oils.