Ok to mix HDEO and PCMO?

[FCD]

My '88 Escort only takes about 3 liters or quarts to do an oil change.
Right now i have a 5L jug with 2 Liters of oil left in it, it's an oil i cannot get locally, but i do have a 1 liter / quart that i bought just in case for a road trip that i have not even opened of Shell Rimula R4X 15W-40 HDEO ( Dino ).
Would it be ok to use it for my next oil change mixing it with the other 2L i have left in the jug? it's a 10W-40 Syn-blend...

Bonus pic of the car in question ( left )

Cars and Coffee, 22-07-2018 by Argentum Enim in Sempiternum, en Flickr

 

[BrocLuno]

Yup. It'll just be syn-blendier

 

[SirTanon]

I've done it before in my Fusion. No issues to speak of. I doubt you'll see any issues in your car.

 

[sw99]

I have run a bunch of HDEO's in the 15w40 and 10w30 varities mixed with 5w30 and 5w20 in several cars over the years. Make a good cleaning oil from what I have seen.

 

[walterjay]

You will be good. I have done similar with no problems.

 

[spasm3]

I'm tempted to run an hdeo in my direct injection engine.

 

[two4spooky]

Originally Posted By: sw99
I have run a bunch of HDEO's in the 15w40 and 10w30 varities mixed with 5w30 and 5w20 in several cars over the years. Make a good cleaning oil from what I have seen.
Same here, almost every change. I use remains of dino and synthetic HDEO jugs to finish off OC in passenger vehicles for 15+ years. I still have both vehicles which were bought new, one with 140+k and the other with almost 240k miles. Both original engines still run great and neither show any appreciable oil consumption FWIW.

 

[CT8]

oil is oil look at the uoas they all pretty much have the same additives.

 

[double vanos]

Mix away!

some of our best UOAs are on Frankenbrews.

 

[FCD]

Ok, thanks!

 

[JAG]

Originally Posted By: CT8
oil is oil look at the uoas they all pretty much have the same additives.

You apparently haven’t seen test results for most of the major brands for tests that are used for oil specification testing. I don’t have the link right now, but oil is NOT oil. Results vary considerably. Also, not all oils can pass all of the tests for some specifications. Lastly, seeing metallic element concentrations in UOAs and VOAs doesn’t come allow one to predict oils’ similarites and differences in terms of performance.

 

[FCD]

I think i'm going to change the oil sooner than expected, the other day one of the hydraulic tappets decided to rattle for a couple minutes on starting it from cold, it doesn't anymore but even before that i thought it had more valvetrain noise on the syn-blend i am running now than the Rimula Dino HDEO.

It's got over 100k miles and 30 years with the internals untouched so probably likes the thicker HDEO.

I've already looked up the price of a new camshaft and lifter kit just in case though as it's a well known issue with the Ford CVH.

 

[TheLubinator]

Mix with confidence, nothing bad will happen to your engine because of it.

-The Lubinator

 

[Shannow]

Nothing will blow up...for sure.

Do you have an oil at least as good as either of the constituents ?

Unlikely.


Do you have an oil that will pass all of the tests that either of the originals pass...very unlikely

 

[FCD]

Yeah, but are the specs of either oil far better than anything available in 1988? Probably!
We'll see if i mix or go back to only 15w40 HDEO as it was quieter on that Rimula R4X than what i am running now.

 

[Shannow]

Originally Posted By: FordCapriDriver
Yeah, but are the specs of either oil far better than anything available in 1988? Probably!
We'll see if i mix or go back to only 15w40 HDEO as it was quieter on that Rimula R4X than what i am running now.


Not saying that it's not as good as 1988...

It's just all this "mix it it's all good" nonsense, is really "nothing will blow up"...that's pretty much all that is likely.