Mixing 0w20 with 0w40?

[jims5600]

Hi, My 14 Silverado 5.3 calls for 8qts for a oil change with filter. The
recommended weight by GM is 0w20. I have a few quarts of 0w40.
Can I safely mix these two weights? Like 6 qts 0w20 to 2 qts 0w40?
I only put on about a 1000 miles a year on this truck,change oil every
year.
Thanks

 

[Deleted member 89374]

Go for it. What could go wrong?

 

[kschachn]

Lots and lots of other threads on mixing but this is recent. Mixing grades is irrelevant in terms of “safety”.

Additive Clash

Admittedly, I had never heard of this concept until a few years ago. And I can’t seem to find much on it except that it is a possibility. I thought part of the API standards was a requirement for compatibility with other oils of the same rating, as well as backwards compatibility? Both of my...

bobistheoilguy.com

 

[Brian123]

Hi, My 14 Silverado 5.3 calls for 8qts for a oil change with filter. The
recommended weight by GM is 0w20. I have a few quarts of 0w40.
Can I safely mix these two weights? Like 6 qts 0w20 to 2 qts 0w40?
I only put on about a 1000 miles a year on this truck,change oil every
year.
Thanks

You will find out if you do this, do you have AFM or VVT on this Vehicle?

 

[TurboChris]

It will be completely fine.
Currently running 0w40 in my VVT Silverado and have been for years. Have ran 15w50 in it as well with no adverse affects.

 

[Bill_W]

If you are asking, then you have worries.

 

[kschachn]

You will find out if you do this, do you have AFM or VVT on this Vehicle?

That will make no difference whatsoever.

 

[JeffKeryk]

Our beloved Tundra is running 5w30 + 10w30 M1. Maybe high mileage? Just because...

 

[blufeb95]

Unless it's Pennzoil Ultra Platinum 0W40 being mixed with 0W20 Pennzoil, or 0W20 Mobil1 ESP being mixed with 0W40 Mobil1 ESP, I wouldn't recommend mixing most 0W20 products with 0W40 as 0W40 with the exception of PUP 0W40 are High SAPS or Mid-SAPS Euro oils that likely have different additive chemistry than almost off the shelf 0W20, while they are miscible the final product will likely perform worse mixed than when used separately.

 

[Dave1027]

It will run fine with that mix. You might even notice the engine sounding a little smoother. May lose .01 MPG oh no!

 

[OVERKILL]

Lots and lots of other threads on mixing but this is recent. Mixing grades is irrelevant in terms of “safety”.

Additive Clash

Admittedly, I had never heard of this concept until a few years ago. And I can’t seem to find much on it except that it is a possibility. I thought part of the API standards was a requirement for compatibility with other oils of the same rating, as well as backwards compatibility? Both of my...

bobistheoilguy.com

Yup, exactly. It's just not ideal. Most likely negative interaction would be a reduction in the Winter rating performance.

 

[Deleted member 89374]

That will make no difference whatsoever.

Depends on ECU programming, thermostat, etc. Once I went to a 180F thermostat and deleted the grille shutters in the RAM 1500, the HEMI became more sensitive to viscosity in terms of VVT and MDS actuation. That's because, as @OVERKILL said, I doubled down on MOFT. A 2~4cSt difference in cSt at operating temperature won't make a difference, you're right. But when your new operating temperature is around 185F to 190F down from 225F, then a 10cSt will make a difference and you'll see it manifest itself in the fuel economy taking a dip, mostly. Realistically, even running ILSAC 5W-30 in that HEMI, I'm losing around 2 MPG on average. Happiest I've seen that engine was on 0/5W-20 with the cold thermostat. I think that engine would be a very good candidate for the HPL "Overkill" 0W-20.

It all goes down to the temperature-viscosity relationship.

However, you're absolutely right: in a stock engine, it won't make a difference.

[Edit]

I also change the intake with the one from the 3.0 EcoDiesel, so now it can suck twice as much air as it did before. This resulted in better low-end torque. In practice this means that it drives like a limo now, even when towing my empty trailer that weighs ~1000lbs.

 

[Passport1]

Every vehicle is its own chemistry experiment. For the sake of (our) scientific curiosity,

 

[jetman]

It will be fine

 

[Slow Car Sport Mode]

Doo eet.

 

[Bighorn2500]

Using Mobil 1 0w20 & 0w40, I do it in a Pentastar V6 Durango at 5:1 ratio.

Comes out to be 48.5@40c/9.4@100c pretty much a thick 20 or very thin 30 weight.

 

[Brian123]

That will make no difference whatsoever.

Is what you are saying an opinion or a fact ?

 

[LDB]

Hi, My 14 Silverado 5.3 calls for 8qts for a oil change with filter. The
recommended weight by GM is 0w20. I have a few quarts of 0w40.
Can I safely mix these two weights? Like 6 qts 0w20 to 2 qts 0w40?
I only put on about a 1000 miles a year on this truck,change oil every
year.
Thanks

So mixing those in that ratio creates 00W25?

 

[Hall]

Is what you are saying an opinion or a fact ?

Every response here is opinion

 

[cheesepuffs2]

Depends on ECU programming, thermostat, etc. Once I went to a 180F thermostat and deleted the grille shutters in the RAM 1500, the HEMI became more sensitive to viscosity in terms of VVT and MDS actuation. That's because, as @OVERKILL said, I doubled down on MOFT. A 2~4cSt difference in cSt at operating temperature won't make a difference, you're right. But when your new operating temperature is around 185F to 190F down from 225F, then a 10cSt will make a difference and you'll see it manifest itself in the fuel economy taking a dip, mostly. Realistically, even running ILSAC 5W-30 in that HEMI, I'm losing around 2 MPG on average. Happiest I've seen that engine was on 0/5W-20 with the cold thermostat. I think that engine would be a very good candidate for the HPL "Overkill" 0W-20.

It all goes down to the temperature-viscosity relationship.

However, you're absolutely right: in a stock engine, it won't make a difference.

[Edit]

I also change the intake with the one from the 3.0 EcoDiesel, so now it can suck twice as much air as it did before. This resulted in better low-end torque. In practice this means that it drives like a limo now, even when towing my empty trailer that weighs ~1000lbs.

Why did you swap to a colder thermostat?