Shell Rotella - T4, T5, or T6???

[mvweebles]

I need some oil - have decided on Shell Rotella due to local availability. Question is T4 (oil), T5 (synthetic blend), or T6 (synthetic)? My inclination was T6 but I came across this YouTube review and looks like T5 might be a better choice. I grabbed a screenshot of the findings to save y'all 11-mins of your life listinening to an unscripted narrator turn a 2-min vid into a 12-min one.

Engines: Old-school Perkins 4.236 75hp taking 2-gals; Northern Lights 6kw with 3-cyl Shibaura natural.

Thoughts?

Peter

[Bacchus]

Peter best / most applicable article I've found relative to marine application can be found on my Bacchys Website - Useful Links - Cox Eng Yacht Eng Oils
https://dkloeber.wixsite.com/bacchus/links
Latest version & syn not always the "best" choice. Our engines are not what they are optimized for.

[mvweebles]

Originally Posted by Bacchus

Peter best / most applicable article I've found relative to marine application can be found on my Bacchys Website - Useful Links - Cox Eng Yacht Eng Oils
https://dkloeber.wixsite.com/bacchus/links
Latest version & syn not always the "best" choice. Our engines are not what they are optimized for.

Thanks - helpful.

Here is the direct link. In short, old engine, old oil. CF-4 would be my approximate vintage for the Perkins - T4 would be the closest of the three I posted. Will have to look at the NL 6kw.

https://26ed2d06-9e49-4586-8f39-2a05...2cd51b9dbc.pdf

Honestly, I'd heard that synthetics shouldn't be run in older engines, but have heard more recently that it's not an issue. Go figure.

Peter

[Delta Riverat]

My engines are from 1979. I don't think they had synthetic oil back then. And the additives were no where near as good as today. I'll keep using good old petroleum.

[O C Diver]

My John Deere was built in 2013. Manufacturer specified regular diesel motor oil like T4. I had higher than I expected wear metals with the manufacturer's premium oil. After the warranty period was up, I switched to Rotella T4. Wear metals declined to well below Blackstone's universal averages. Like Rotella T4 and have been using it for a long time. My Dodge pickup with the Cummins 6BT 220 HP engine now has close to 525,000 miles on it.

Ted

[KnotYet]

Rotella T4 for a normally aspirated diesel. T5 only if T4 is not available, IMO.
We tend to change engine oil long before the advantages of synthetic really help.

[Hippocampus]

Believe Cummins suggests you not use semi or full synthetic. Don’t know the reason but have avoided them. Would ask your engine manufacturer for guidance. If no longer in business a professional like Steve D’A

[rslifkin]

Realistically, any of the 3 are likely to do just fine in your engine. I use HDEO oils (typically Rotella or Delo) in most of the engines I take care of. I generally swap between those 2 brands based on price and availability.

Currently I've got a car at home with Rotella T6 5W-40 in it, another car with Delo 5W-40 syn, same in the snowblower too. Just put T6 5W-40 in the dinghy outboard. Boat engines and gen all have Delo 15W-40 semi syn in them. I used to use T4 or the basic Delo in the boat, but at some point I started finding the semi-syn versions cheaper than the dino stuff, so I switched.

I've never seen an issue from using synthetic in an engine that doesn't need it. Realistically, as long as an oil meets the basic needs of an engine, is an appropriate viscosity, and is changed before it's worn out then you should be in good shape. As OCdiver found, some engines can be a little more picky than the basic specs indicate. So oil analysis is a good idea to confirm good wear metals and determine how long the oil you've chosen is holding up.

[Pete Meisinger]

Old school engine, go with old school oil. No need for the synthetic.

pete

[BruceK]

Fairly sure a previous TF thread established synthetic is not actually synthetic.

[TowLou]

Ill jump in saying older motor no need for synthetic oil. Not as many tight clearances oil is forced throu compared to a modern electronic motor.

[TowLou]

Originally Posted by BruceK

Fairly sure a previous TF thread established synthetic is not actually synthetic.

I am under the impression they are all blends that have a dyno base.

[ranger58sb]

Originally Posted by mvweebles

Here is the direct link. In short, old engine, old oil. CF-4 would be my approximate vintage for the Perkins - T4 would be the closest of the three I posted.

Honestly, I'd heard that synthetics shouldn't be run in older engines, but have heard more recently that it's not an issue. Go figure.

I've read that, too. True or not, I'd use T4 in your case. No significant advantage from the synthetics, I think.

Might be different if you don't want/plan to change oil annually... but I think I'd check with a Perkins and/or Shibaura (?) guru before you do that.

We had Cummins 450s in the previous boat, and they specifically recommended not using synthetic.

Originally Posted by TowLou

I am under the impression they are all blends that have a dyno base.

Maybe, but some (like T6) say "full synthetic" and I'd have guessed they can't fudge the language too much.

-Chris

[jleonard]

I would also stick with T4. With any of those you won't have an oil related failure.

[rslifkin]

Originally Posted by BruceK

Fairly sure a previous TF thread established synthetic is not actually synthetic.

There are a couple types of synthetic base stock. Some don't consider a group III synthetic to be actually synthetic, but only groups IV and V. Group III is basically a synthetic that's made using petroleum as an input material.

[mvweebles]

T4 even though T5 has better anti-wear additives and a smidgen better detergent additives?

Peter

[rslifkin]

Looking at the additive numbers, I'd lean slightly towards the T5 for an older engine design, although I expect it wouldn't make a big difference in wear between any of them. The T4 is slightly thicker at high temps, but I wouldn't expect that small difference to matter in most cases.

[twistedtree]

Originally Posted by mvweebles

T4 even though T5 has better anti-wear additives and a smidgen better detergent additives?

Peter

Maybe this is overly simplistic, but if the engine calls for grade C-whatever, isn’t that what you should use? Each new C designation is backwards compatible, so I guess I don’t see what the fuss is all about. Use a reputable brand that meets the specs and go cruising. Really, have you ever heard of an oil related engine failure when the manufacturer’s recommended oil spec was used?

[mvweebles]

Originally Posted by twistedtree

Maybe this is overly simplistic, but if the engine calls for grade C-whatever, isn’t that what you should use? Each new C designation is backwards compatible, so I guess I don’t see what the fuss is all about. Use a reputable brand that meets the specs and go cruising. Really, have you ever heard of an oil related engine failure when the manufacturer’s recommended oil spec was used?

Some complications due to being south of border. The oil I find in Mexico is either a brand I am not familiar with, or one that I am pretty sure is at the lower end of the quality heap (STP). Finding diesel oil is a subset. So I will grab it in San Diego. All three on the shelf, and price differential is not an object - just trying to decide on which one. I initially thought the T6, but seeing the comparison on T5, looked compelling. I realize any of them will provide excellent lubrication, much better than the oils available when my circa 1990 Perkins was built.

I pinged a very knowledgeable friend who happens to have a Perkins 6.354. While I didn't ask the synthetic vs conventional question, he said he runs Delo 400 15-40 (CK-4 or CJ-4) and said the Shell Rotella equivilent is fine. I believe any of the three Rotella Oils are CK-4/CJ-4 compliant.

Peter

[mvweebles]

So I did a bit more research. All three Rotella oils - T4, T5, and T6 - are CK-4 and CJ-4 compliant. There are long lists of engine manufacturer approvals for all three (though not Perkins which is understandable).

Further, I looked at the data sheet for each and summarized several of the metrics. The appear more similar than different. My best-guess is the pour-point and viscocity numbers would make a difference for truckers who operate in very cold conditions, but for the most part, subtle differences for my engines would be meaningless. That said, i was impressed with the higher anti-wear characteristics noted in the video I originally posted. I will probably go T5, but would be happy with the other two as well, but would be wasting a few bucks

Peter