# Mixing types and grades of Mobil 1

#### Scott P

The time has come to change the oil in my MazdaSpeed 6. I bought two jugs of Mobil 1 0W-30 AFE to get the \$10 rebate. The car takes six quarts or so. I was thinking about grabbing a Mobil 1 oil change special from AutoZone with some 0W-40 European Formula for my car and a couple of quarts of 5W-20 for our CX-9. I'm hoping the one quart of 0W-40 might give a little boost to the 0W-30 to help with fuel dilution and the hot weather we've had in Houston. Will there be a problem? Is the one quart really going to make a difference at all?

#### Bill in Utah

Staff member
No difference in anything. A quart is not going to "boost" anything IMO. Mix away.

#### drive4show

Based on BITOG reading, I use this Rohmax Base Oil Mixtures web page, to determine the final viscosity of my brews. At 100C, M1 0w30 AFE viscosity is 11.0 cSt. And M1 0w40 viscosity is 14.0 cSt. 5 quarts of 0w30 AFE, and 1 quart of 0w40, gives you a mix that is 83% 0w30 AFE. Plugging in these numbers into the top calculator results in a final viscosity of 11.45. So, did you boost the 0w30 AFE? Yes, a bit... Hopefully I am doing this viscosity determination correctly....

#### Bill in Utah

Staff member
Originally Posted By: drive4show
Based on BITOG reading, I use this Rohmax Base Oil Mixtures web page, to determine the final viscosity of my brews. At 100C, M1 0w30 AFE viscosity is 11.0 cSt. And M1 0w40 viscosity is 14.0 cSt. 5 quarts of 0w30 AFE, and 1 quart of 0w40, gives you a mix that is 83% 0w30 AFE. Plugging in these numbers into the top calculator results in a final viscosity of 11.45. So, did you boost the 0w30 AFE? Yes, a bit... Hopefully I am doing this viscosity determination correctly....
So 11.0 vs 11.45? I stand by my answer... No difference! (and I did not have to do the "math")

#### Nederlander75

Mobil will also tell you to mix away, their oils are completely compatable with each other.

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#### StevieC

Originally Posted By: Nederlander75
Mobil will also tell you to mix away, their oils are completely compatable with each other.
I would hope so! Watch out for those snobbish oils though... I hear they can be real Biatches sometimes and not mingle well together!

#### crinkles

don't do it. you'll blow your engine

#### ViragoBry

Hey Scott, Have you had any problem with smoking after extended idle times? That's a huge problem with the MS6 and last I heard, Mazda is recommending the installation of 5W-40 to 'cure' it. If that's not successful, it's a turbo replacement. I haven't had the issue, knock on wood..but I just clicked over 10,000 miles yesterday. I don't know what the operating temp viscosity difference is between 5W-30 and 0W-30, (if there is any at all) but if its any thinner, it could cause you a problem. The thin stuff is making its way past the turbo seals.

#### drive4show

Here are 100C viscosity values (in cSt) from the M1 Product Data Sheets, available online: 10w30 .... 10.0 0w30 AFE . 11.0 5w30 ..... 11.3 10w30 HM . 11.8 0w40 ..... 14.0 10w40 HM . 14.7 15w50 .... 18.1 I was looking to thicken up a stash of M1 10w30....

#### raotime

Does this mean 5w-30 is more viscous than 10w-30? I am a new guy here, and I am trying to understand oil better. Thanks.

#### CATERHAM

Yes and no. Below 25C the 5W oil will begin to get progressively lighter relative to it's 10W counterpart and continue to do so as the temperature drops. And at the other temp' extreme, 150C, the 10W has a higher HTHS viscosity than the 5W. This is all because the two oils are quite different in the viscosities of their base oils and the 10W has very little if any VII. Isn't motor oil interesting?

#### Audi Junkie

Mix the SuperSyn grades, but not with the 5w-40 Turbo Diesel Truck.

#### Scott P

Thread starter
Thanks for the advice everyone. I've been lucky and not experienced any smoking issues with my turbo and I'm at 22,000 miles. I was just thinking that the one quart of 0W-40 would give me a little boost to the viscosity. I also wanted to make sure that there weren't any large differences in the chemistry of the different Mobil 1 types.

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