Can I add a little 0W40 to 5W40?

[tiredguy]

Hi

I have a 2006 VW Jetta 2.5L and am about to change the oil. I bought a 5 quart jug of 5W40. The vehicle takes around 6.5 quarts.

I have a jug of 0W40 that has a little less that 2 quarts in it.

Can I use it along with the 5W40 for the change?

 

[Kira]

DO NO do it. You'll seize your engine almost instantly.
Standby for more serious responses.

 

[4WD]

Hi

I have a 2006 VW Jetta 2.5L and am about to change the oil. I bought a 5 quart jug of 5W40. The vehicle takes around 6.5 quarts.

I have a jug of 0W40 that has a little less that 2 quarts in it.

Can I use it along with the 5W40 for the change?

0.5 won’t hurt - more will ……………
Same brand ?

 

[short]

DO NO do it. You'll seize your engine almost instantly.
Standby for more serious responses.

Kira is correct.

 

[edyvw]

Hi

I have a 2006 VW Jetta 2.5L and am about to change the oil. I bought a 5 quart jug of 5W40. The vehicle takes around 6.5 quarts.

I have a jug of 0W40 that has a little less that 2 quarts in it.

Can I use it along with the 5W40 for the change?

For next oil change in Honda, I am using 2qt M1 0W20, 1qt of M1 0W40, and some leftover M1 ESP 5W30.

 

[oldhp]

Use it. Won't hurt a thing. Engine won't know.

 

[Lubener]

You can mix 20w-50 with it , if you wanted.

 

[demarpaint]

Yes.

 

[CharBaby]

YES, you can mix oils.
I know that the first 3 responses were joking but some members may not. It can cause confusion.

 

[SR5]

Yes you can.
The first three responses were a joke.

 

[burbguy82]

Hi

I have a 2006 VW Jetta 2.5L and am about to change the oil. I bought a 5 quart jug of 5W40. The vehicle takes around 6.5 quarts.

I have a jug of 0W40 that has a little less that 2 quarts in it.

Can I use it along with the 5W40 for the change?

If they were the same brand, I would do it, but not make it a habit. If they are not the same brand, then no, I would not.

 

[Urshurak776]

If you think you're gaining anything by mixing, you're not.

If you're mixing because you are just trying to get to full on the dipstick, go for it. Won't hurt a thing.

 

[Lawnfella]

Hi

I have a 2006 VW Jetta 2.5L and am about to change the oil. I bought a 5 quart jug of 5W40. The vehicle takes around 6.5 quarts.

I have a jug of 0W40 that has a little less that 2 quarts in it.

Can I use it along with the 5W40 for the change?

No your engine will self detonate

 

[CheezWhiz]

are there any oils that really should not be mixed? like say you mixed 20w-50 vr1 conventional with a 0w-8, these are still compatible?

 

[JavierH19]

Every oil change you do involves you mixing old oil with new oil even if you do take the oil filter off and let it drain to a slow drip. There's a wet capacity/service fill and dry capacity/dry fill but the dry fill is from when it's first assembled and first filled and from then it's the wet capacity/service fill which is lower and if ever torn down and rebuilt you'd be filling it by the dry capacity. There's always old oil in the oiling system and I'm not talking a few ounces but sometimes a quart or more so you're pretty much always mixing at least half but usually a whole quart and sometimes more in larger engines even with a filter off oil change.

 

[JavierH19]

are there any oils that really should not be mixed? like say you mixed 20w-50 vr1 conventional with a 0w-8, these are still compatible?

Well of course they'll mix and have zero chemical reaction. Pretty much all motor oil will mix but of course that doesn't mean that the worse of the two won't lower the effectiveness of the better one.

 

[Nessism1]

Last oil change on my car, I mixed three different brands, and two different weights. I also reused the filter, after dumping it out. Why? Because I had a bunch of leftovers in the garage going to waste. The engine doesn't care.

 

[OVERKILL]

Well of course they'll mix and have zero chemical reaction. Pretty much all motor oil will mix but of course that doesn't mean that the worse of the two won't lower the effectiveness of the better one.

Quoting myself from another thread with a few tweaks here:

Mixing oils isn't "optimal" because the odds of you improving something are infinitesimally low but negatively impacting some aspect of the chemistry, quite probable. It could be a reduction in low temperature performance (most common), an increase in Noack, throw off the FM balance...etc. Lots of things to "go wrong" which is why oils are fully formulated products and not Jebediah with a butter churn and some raw ingredients tossing this stuff together in a shed.

That said, unless you actually put the mix, and the products you mixed individually through the testing sequences, you really have no idea what has changed from the performance of each of those constituents alone. It's not something Joe Average is going to be able to determine from sight/smell/taste/feel or from a UOA and the odds of it having any easily discerned impact on longevity are low. Rings coking up, varnish build-up...etc, these things don't happen overnight or even over the course of a couple (normal) OCI's.

In the case of being frugal and using up surplus product, while I generally don't recommend mixing as a regular practice, what the OP is considering doing is quite reasonable.

 

[Steve_Crewdson]

Likely going to start an infinite nuclear chain reaction that disintegrates the universe. Do not advise.

After further consideration, no problems will result. Mix and enjoy.

 

[oil pan 4]

Yes they'll mix just fine. Make sure you're using an oil that has the VW spec. When I used to have a VW I found that not that many oils carried the VW spec.
If no VW spec change oil at 3,000 miles.