mixing brands but not weights/viscosities

[Riptide]

I've read on here before that it's fine to mix say PP and PU. But what about adding a third brand in there?

Say the car wants 4.5 qts. So you put in 2 qts of PU. 2 qts. of PP. And half a quart of motorcraft synthetic blend. Keeping the same weight and viscosity.

Is mixing the motorcraft in with the two pennzoils going to be an issue?

 

[WiskyBadger]

Non issue mix away. Might not be any kind of advantage to doing it other then getting rid of old oil.

 

[SilverC6]

I'd use a short OCI with a Frankenstein mix.

That's just me.

All kinds of repressed chemists here though will tell you everything is fine with your proposal.

I always look at the least desireable oil in the mix as the weakest link in the chain.

Buy some more Pennzoil and use the MC as make up oil late in the OCI.

 

[Riptide]

We would be putting about 5000 miles on this fill and it would be over 4-6 months.

 

[CELICA_XX]

I am super picky about this... I won't even mix my SM/SN PU of the same weight.

 

[Rand]

If the oils use different additives it can be a significantly inferior oil than the oils were prior to mixing.

mixing the same oil in different weights is much better than mixing 2 random oils together.

ie: pyb 5w20 and 10w30 =ok

M1 0w20 and valvoline 10w30.. not so ok. Would your engine explode? no.. but the mixed oil is not as good.

 

[gregk24]

I dont mix different brands. When I needed to top off the Quaker State Ultimate Durability synthetic in the Uplander, I went out and bought some Quaker State Defy blend.

 

[05LGTLtd]

type of vehicle?

Age/Miles on vehicle?

Severity of use in 5K oci, towing, extreme heat, high rpms, excessive idling, etc?

I don't see a particular problem with the mix you propose, for most cars on the road under normal operating conditions. not really enough MC in the blend to dilute out the strong add packs of the PP/PU.

 

[Riptide]

2009 ford focus ses
26k miles at start of fill

Would be 5000 miles on the fill of which 4500 would be highway.

 

[05LGTLtd]

Not sure it matters, but PYB is ~$4.xx at Walmart for a quart. QSGB is a bit less. Either of those have a similar addpack approach to the PU/PP and would pose less of additive issue. Save the MC for top off, or buy four more quarts and use for your next OCI.

Are you still under warranty? if it was 129K, I wouldn't blink at your blend. Still probalby not an issue given it is a conservative oci and easy miles...

 

[Riptide]

Well shoot. I was hoping for unanimity on this. Now I'm not so sure about doing it.

Basically I've got a mix/match of 5w20 at my disposal and I need to change the oil before we drive the car on a 3000 mile round trip in July. Then another 1500 mile round trip shortly afterwards. All highway miles.

If this is a bad idea - is there harm in using the Motorcraft 5w20 with my craftsman lawn mower? The manual calls for 30 viscosity oil.

 

[HTSS_TR]

Originally Posted By: Rand
If the oils use different additives it can be a significantly inferior oil than the oils were prior to mixing.

mixing the same oil in different weights is much better than mixing 2 random oils together.

ie: pyb 5w20 and 10w30 =ok

M1 0w20 and valvoline 10w30.. not so ok. Would your engine explode? no.. but the mixed oil is not as good.

Agree. Same brand, similar type but different weights is in my E430 now. 5 qts M1 AFE 0W20 + 2 quarts M1 0W40 + 1 quart M1 HM 5W20.

I tried not to mix brands, regardless same or different weights.

 

[Zaedock]

Come on guys. There is not one shred of evidence that mixing several different brands is "not as good" or "significantly inferior".

I have a UOA kicking around from my wife's Maxx that had AT LEAST 5 different brands of leftover oil and it was fine.

The worry is completely overblown.

 

[HTSS_TR]

There is no evidence of any harm mixing different brands, but it's not optimal, mixing same brand is usually safer.

 

[fdcg27]

No issues at all.
I avoid doing this now, but back in the day I mixed brands freely and have nothing ill to report from the practice.
I'm assuming that you propose to do this to use up some odds and ends?
Go ahead and do it.
There are UOAs posted here of blends of oils of at least three different blenders using at least three different basestocks and they look just fine.

 

[Ayrton]

A couple of the older vehicles I assist in looking after, once I've done oil change, they top off with a myriad of different oils (same viscosity). I try not to do it myself, but it doesn't seem to hurt.

 

[NormanBuntz]

That blend you're proposing is only 10% Motorcraft and 90% SOPUS. I wouldn't lose any sleep over that.

 

[A_Harman]

I say it won't be a problem. Motorcraft syn blend is good oil. It's not going to mess anything up at 11% concentration in a blend of Pennzoil oils that is only going to be used for 4500 highway miles.