Shell Rotella T4 vs T6 for Yanmar 6LYA-STP

[PocketAces]

Hi. I have used Shell Rotella T4 in my Yanmar engine for 10 years. Good results from Oil testing every year. Right now, in Vancouver BC, I cannot find the T4 anywhere (supply chain issues?), but I can get T6 (Synthetic). I understand that T5 is partially synthetic.
So my question is if I get some T6 and mix it with the last of my T4 for my oil change, would that be a bad thing or would it be similar to simply using T5 which is a blend anyway? Or must it be all one of the other?
Tony
Pocket Aces, Mainship 34T '08.

 

[KnotYet]

Obviously you could order the oil you want over the internet but if you'd rather
buy it locally your supplier ought to be able to order you some.

If your Yanmar has a turbocharger I would at least try T5 in it.
T6 is my go-to here for anything with a turbo.

I see no reason to mix oils yourself unless it is an emergency top-up.

 

[ranger58sb]

Hi. I have used Shell Rotella T4 in my Yanmar engine for 10 years. Good results from Oil testing every year. Right now, in Vancouver BC, I cannot find the T4 anywhere (supply chain issues?), but I can get T6 (Synthetic). I understand that T5 is partially synthetic.
So my question is if I get some T6 and mix it with the last of my T4 for my oil change, would that be a bad thing or would it be similar to simply using T5 which is a blend anyway? Or must it be all one of the other?

Does your Yanmar manual speak to dinosaur oil versus synthetic?

-Chris

 

[PocketAces]

Thanks for the feedback. The Yanmar manual does not contain the word "Synthetic", so presume that Dinosaur oil is okay (if not the best). I recall a discussion on the old Mainship forum a while back where use of dinosaur oil was considered okay as long as you changed the oil annually. Use of synthetic oil in cars extends the time between servicing, but the discussion on that old forum was that even if you used synthetic oil, you should change oil annually anyway.

The feedback did not answer my question however. Is mixing oil "bad"? For example, blending wines can be a good thing while mixing lemon juice and milk is not good. I have around 10L of T4 and even if I transition to T6 in future, I would still want to use up my existing oil. So I believe it is okay to use it up and top up with T6 in preparation to use T6 in future years.

Also, I can get T4 at Walmart at about Cdn$65 (if it were in stock) but Amazon is about $160 online while T6 is $170 (from a store). So online T4 is basically the same cost as local T6.

Tony
Pocket Aces, Mainship 34T '08

 

[Ski in NC]

No harm mixing T4 and T6. Use which ever is available without worry.

 

[Arc]

I have never seen a diesel go Kaboom from ‘wrong’ oil. But I only been working on them for 40 years.

 

[PocketAces]

That’s what I needed to hear. Thanks!

 

[Bkay]

I just spent some time researching T5 Vs. T6 and spoke to quite a few experts (and a few dopes, but they were pretty easy to spot).

Bottom line, they agree with Ski's comment above no harm mixing. One guy even advocated mixing T4 and T6 vs. using T5. His heartburn was Shell wouldn't disclose the mixture they used when he did some type of factory tour. He said at least if he mixed it he'd know what the ratio of dino to synthetic is (40:60 - whatever).

Not sure I'd do that forever, but while supply chains are messed up, I agree with the guys above. BTW - I'm assuming you are only considering using the same weight of oil in the mixture, right?

Let us know if you observe anything that seems out of wack when you do it.

 

[fryedaze]

https://comparemotoroils.com/shell-rotella-t4-vs-t5-vs-t6/

A little added info.