Okay to Mix These?

[HLN_OR]

Hello,

I recently got a good deal on some Castrol GTX 5w-20, but still have a couple quarts of Supertech synthetic 5w30 left. Wondering if it's fine to mix these different oils of different weights, or would it be better to just buy another few quarts of the synthetic before using the 5w-20. Thanks.

 

[UNC038]

I wouldn't mix them. I would think, you'd end up with a sub-par mix.

 

[pp_rp]

It won't hurt. Change out aroud 3000 miles.

 

[Seth]

I once mixed two different oils across SM, SL, dino & synthetic. No problem whatsoever. There was another guy paulinfiji I believe mixed four different brands across 3 different viscosities...

 

[TallPaul]

I've mixed all sorts of oils together. No problems.

 

[Cooper]

I mixed this up for a 4k OCI. It is what I had left over at the time from other OCI's.

2 qts. 5w30 Pennzoil SM
1 qt. 5w30 Mobil Clean 5000 SM
1 qt. 5w30 Mobil 1 SM
1/2 qt. 0w30 Green German Castrol SL

It worked just fine in my Toyota RAV4. It was the last OCI before I started the first of two Auto-RX cycles. I had no problems, and the oil looked pretty good while being drained.

 

[Triple_Se7en]

Mix away!!!!

 

[Camu Mahubah]

You can mix if you want to... I used to alot when I was a younger man. I couldn't afford to run synthetic so I would buy 4 quarts Valvoline All-Climate 10w30 at $1.19 a piece and one quart Castro Syntec 5w50 at $3.69. I wanted some heavy synthetic for the bearings or whatever I can slightly remember what I was thinking. The Ranger I ran it in loved it I guess. I beat and beat on it and it was running like swiss watch when I sold it. Now that I have a slight income I don't mix anymore. But if I had a beater I'd be mixing again.

 

[Camu Mahubah]

I mixed because Discount Auto at that time only carried two brands of syn Castrol and Mobil 1. Otherwise I would have mixed valvoline syn with valvoline conventional. I always thought at that time in my life (I was 16) that Castrol would have an additive that Valvoline didn't. When I die I am gonna ask whoever for a used oil analysis on that stuff I ran...

 

[Camu Mahubah]

The wierd thing is I was kinda right because Castrol has moly and Valvoline doesn't.

 

[levi]

Quote:

---

I've mixed all sorts of oils together. No problems.

---

Ditto.

Your motor will not blow up. If it does, it was not the oil that caused it.

Seriously.

 

[HLN_OR]

This is kind of a delayed update, but both oils were installed, and after one day it turned the color of pancake syrup (valves seem quieter though). Didn't notice this last time or when I've used Syntec (maybe I only checked right after the change and not again the same week). I take it this is normal & harmless, for one or both oils?

 

[junebug]

I am age 50. In my teens and 20's, I NEVER would mix different brands. Now however,I like witches brews and have had no problems. Also, I prob. would NOT mix on a new car,just "beaters"!!

 

[Steve S]

What does the information on the packaging indicate on the mixing of oils?

 

[bobfather99]

Quote:

---

Quote:

---

I've mixed all sorts of oils together. No problems.

---

Ditto.

Your motor will not blow up. If it does, it was not the oil that caused it.

Seriously.

---

What they said, mix away!!!

 

[HLN_OR]

Quote:

---

What does the information on the packaging indicate on the mixing of oils?

---

The Supertech synthetic says it's compatible with "leading" conventional and synthetic oils (whatever that means), and the GTX says nothing as far as I can tell. I'll stick with it for 3K or so before switching back to my 4500-5000 mile interval.

 

[wsm41bn]

Heres a story about mixing oil, i was driving to oregon, in 6.2 litre diesel truck and i messed up an oil cooler line, i was able to fix it i was low 3 quarts oil. and i had some 10w30 Supertech oil i put in from a another rig of mine. and it worked just fine mixing it with Delo 400 15w40.

So mix away! (normally i stick with the same oil)

 

[Al]

Quote:

---

Mix away!!!!

---

Exactly. Only mix that didn't seem to work very well was RedLine and Castrol 0W-30. UOA wasn't so hot.

 

[ThirdeYe]

I was thinking of mixing the following in my mom's next OCI:

.1 qt Valvoline A/C (leftover from top-offs, etc.)
.5 qt Valvoline MaxLife (leftover from her last oil change, which used 4.5 quarts)
4 qts. Mobil Clean 5000 or Quaker State

Anyone think this would be okay? Her car is an '03 Malibu with a 3.1 engine. I kinda wanna get rid of the odd amounts I have sitting around.. her car takes 4.6 quarts according to the manual, but usually a little overfilled at 4.5 anyways. Planned OCI is 3-4k miles.

 

[BrianWC]

Quote:

---

Quote:

---

Mix away!!!!

---

Exactly. Only mix that didn't seem to work very well was RedLine and Castrol 0W-30. UOA wasn't so hot.

---

Redline doesn't seem to play well with some other synthetics. I mixed a quart of 5W30 with some Mobil 1 10W30 and every time I checked the dipstick it had a couple of bubbles on it.

That being said, it's the only mix I ever have had reason to question. I've mixed a lot of odds and ends to get rid of them. For a while I was mixing Havoline synthetic 5W30 with Mobil 1 15W50 redcap to thin it out a bit....