Good or bad idea: New leftover oil mixed together?

[Dumc87]

Wonder what you guys think about my spare 5 qt Mobil1 Jug that I usually dump my leftover new oil into. The Matrix and the 300ZX I have use about 4qts each, so I usually have a quart leftover from a 5qt jug of whatever oil I used.

Currently the jug has some M1 HM 10w40, Pennzoil HM 5w20, Valvoline FS ML 5w30, 7-11 conventional 10w40.

I figured I'd use the stuff as top up oil, but with all the blends being unique, maybe that aint a good idea... LOL

Would hate to dump new oil into the recycling tank though.

Thoughts?

 

[HerrStig]

Use it in small engines.

 

[KGMtech]

Can you use it in your lawnmower? pressure washer?

 

[Tdbo]

If you have a need for top off, use it for that.

 

[earlyre]

I've done a whole OCI on a leftover frankenbrew. mine was maybe 6 different brands, mostly equal parts 5w20&5w30, mixed a pint(.5qt)at a time.(maintained 2 vehicles that took 4.5 qts)
sent it in for a VOA when i had enough to use, and blackstone saw no issue with the blend.
https://bobistheoilguy.com/forums/ubbthr...mp;#Post3167824

I say just run it.

 

[Olas]

Use it. Maybe not for trackway stuff but in a daily it'll be golden - lots of cars in Europe take 3 or 4 litres so there's always a 'free' change of mixed leftover litres for emergencies..

 

[CR94]

Similarly, I have 9 fl. oz. of Brand R 0W-20 synthetic leftover from the last time I changed oil. Rather than waste it, I'll mix it with ~4 quarts of Brand P 5W-20 synthetic when I change the oil shortly. I'm hopeful that this mixture won't explode or turn into sand.

 

[69GTX]

I don't care about different brands so much, as different add packs. You could end up mixing all 3 major add packs with something unlike all of them.

High calcium, no magnesium, no sodium, boron and moly - SOPUS and M1 0w-40, Castrol Edge 20/30 grades, Valvoline MST 0w-40
Low calcium, high magnesium, no sodium, boron and moly - M1 20/30 grades, Castrol Edge 0w-40
Low calcium, high sodium, no boron and no moly - most Valvoline/NAPA/RP/Schaeffer oils

 

[ThirdeYe]

I've used leftover blends like that before, go for it. It won't be an issue as long as they're all API SM/SN/etc. Before my mom traded in her '03 Malibu, I did an oil change with leftover quarts I had lying around. I think I ended up using 3 or 4 different brands. Ran just fine.

 

[KingCake]

You're always mixing oil, anyway. At least a qt or two stays in your engine after a drain.

 

[CR94]

Originally Posted By: KingCake
You're always mixing oil, anyway. At least a qt or two stays in your engine after a drain.
Some, but "a quart or two" is exaggerating, if we're talking car engines. Only 0.5 liter (or 0.6 quarts), according to the repair manual for my Toyota.

 

[aquariuscsm]

Keep the Z's oil pure. She deserves only the best!

 

[barkingspider]

I think u are good to use that mix, especially for top off oil

 

[Dumc87]

Originally Posted By: aquariuscsm
Keep the Z's oil pure. She deserves only the best!


Haha nope she's getting the Pennzoil pp hm 10w30, thank to you.


The Jeep may like a high mileages synthetic brew though. Hmmm.

 

[fdcg27]

The main concerns with mixes is that the lower end viscosity comes out to some incalculable number, although this could be measured at great cost and is of no concern in Florida and that the blend of oils may not meet the spec of any of the constituents.
So, for a warm weather shortish run, no issues.
There are plenty of members here who have even UOAed runs of wildly disparate mixes with good results.
Not what I'd do for an Ohio winter or for a long run on a car I cared about, but short runs in warm weather should pose no problems.

 

[BrocLuno]

It'll be fine. It's just like being on a road trip and having to top up. You buy what's there and run it. No bigee ...

 

[aquariuscsm]

Originally Posted By: Dumc87
Originally Posted By: aquariuscsm
Keep the Z's oil pure. She deserves only the best!


Haha nope she's getting the Pennzoil pp hm 10w30, thank to you.


The Jeep may like a high mileages synthetic brew though. Hmmm.


Right on!

 

[double vanos]

I wouldn't give it a second thought on a short OCI. Since you know all the oil going into the brew and that it's not contaminated with debris etc I'd give it a shot. Years ago I was faced with the same thing with a 2002 Tahoe. It got a mix of A3 5w30,5w40, 0w30 and A1 0w20, 5w20 and 5w30. The brands ranged from Mobil, Castrol, Pennsoil and Valvoline. 'Old girl never noticed the difference....

 

[Dino01]

I just did this for my Benz oils, had about a quart of Lubro Moly 5w40 and same amount of Edge 0w40, dumped the LM into the Edge bottle, but in my case both are approved 229.5 MB Bevo oils and totally fungible/interchangeable from what I read on an MB forum from an engineer. That said, they'll just be for top ups from here on.

 

[Garak]

Originally Posted By: CR94
Some, but "a quart or two" is exaggerating, if we're talking car engines. Only 0.5 liter (or 0.6 quarts), according to the repair manual for my Toyota.

The only times I've seen it being really high is if there's a rather large oil cooler or something. I think the Mazda RX-8 manual noted that 1.9 litres or something would remain during an oil change. Most aren't that high.

But, if one is OCD, one can always buy large enough quantities of the same product in the same lot number, to ensure nothing is being mixed.