oil mix ?- 5w-20 & 20w-50

[jdw1222]

any thoughts on mixing these 2 dino oils together. I have a bunch of 5w-20 and some 20w-50 and would like to get roughly to a 40w oil

5w-20 is a warren oil and the 20w-50 is penzoil


would I mix these 2 weights at a 50/50 ratio?

 

[kschachn]

You can use the Widman calculator to find out the operating viscosity. The winter ratings cannot be calculated.

 

[jdw1222]

thanks- never knew about that calculator.

so i guess now its just a matter of deciding of its actually OK to mix different oils

 

[ripcord]

All SN oils are required to be compatible. Two different brands mixed together will likely not provide the most ideal additive package but you'll never be able to tell the difference.

 

[OVERKILL]

All SN oils are required to be compatible. Two different brands mixed together will likely not provide the most ideal additive package but you'll never be able to tell the difference.

Yes, they are required to not split like mayonnaise, however, it may have a negative impact on cold temperature performance, whether that's a concern or not is of course going to depend on climate.

 

[gfh77665]

I have done it. Never a problem. Works perfect.

 

[Graham Piccinini]

33 Brands and grades in one crankcase of a supercharged 5.0L Range Rover. UOA shows no negative effects. Last I checked - engine still runs great years and thousands of miles later on whatever oil is cheapest, as it is changed every 3k miles. So mix away and don't overthink it.

S/C Range Rover, 5000kms 33 different oils UOA

Supercharged 510hp Range Rover Sport ran for 5000 kilometers on the mixture of 33 different oils. Voa posted here: https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4735439/Mix_of_33_oils_VOA Each oil was mixed in at the rate of 300ml (10oz) and oils ranged from 0w20 to 10w60...

www.bobistheoilguy.com

 

[blupupher]

Yes, you can mix them, but as mentioned, your "W" rating is thrown out the window, so cold weather starting would be iffy as to what it actually is, and you really have no way of knowing what the actual oil viscosity is, even using the calculator.
I have done it in older vehicles, but would not do it in any vehicle under warranty.
If you are doing it in the Tundra, I would look at doing more of a 60/40 mix or even 70/30 (5w-20/20w-50).

 

[jdw1222]

Yes, you can mix them, but as mentioned, your "W" rating is thrown out the window, so cold weather starting would be iffy as to what it actually is, and you really have no way of knowing what the actual oil viscosity is, even using the calculator.
I have done it in older vehicles, but would not do it in any vehicle under warranty.
If you are doing it in the Tundra, I would look at doing more of a 60/40 mix or even 70/30 (5w-20/20w-50).

No this isn’t for the tundra. I had actually bought the 5w-20 for the tundra prior to stocking up on about 70qts of the clearance RGT 0/5w-20.

hoping that the cold W rating wont be an issue for my application in the summer

so I will be running the RGT in my tundra and was hoping to use the the leftover supply I have of Dino 5w-20 and 20w-50 in my outboard boat motor for some short service intervals while I figure out a Fuel dilution issue. . - so was thinking around 4qts of 20w-50 mixed with 2 qts of 5w-20 would be pretty close

My outboard specs a 10-30 or 10-40 --SE,SF,SG,SJ.

I know conditions are different but It is a suzuki that is the same motor used in a SX4 car