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Rotella users: T4 or T6?

Posted: Tue Aug 01, 2023 5:32 pm
by ChickenPinz
I've moved over to the Rotella camp, using T4 15W40. I'm contemplating T6 for the next change, and am wondering what others, who are using Rotella, ended up with and why?

The T6 is more expensive ($23 vs. $16/gal), but cost isn't a factor given TCO. Anyone see a downside with the T6 vs. the T4?

Re: Rotella users: T4 or T6?

Posted: Thu Aug 03, 2023 8:04 pm
by whitesik
I have always used T4 as recommended by the previous owner who was a Porsche tech at one time working on a lot of air cooled engines. I've got nothing else.

Re: Rotella users: T4 or T6?

Posted: Mon Aug 07, 2023 4:31 pm
by Jim LaGuardia
Use only 30wt per operating instructions.
Rotella T-1 30wt with a bottle of STP with ZDDP additives.
I see firsthand what damage thinner oils do.
If you want it to last, use the right oils.
Thin oils are quickly consumed through valve guides and also cause piston scuffing.

Re: Rotella users: T4 or T6?

Posted: Thu Aug 24, 2023 9:20 pm
by whitesik
OK Jim, Bought some Rotella T1 straight 30 today. Thanks!

Re: Rotella users: T4 or T6?

Posted: Wed Sep 06, 2023 10:14 pm
by ChickenPinz
I conduct oil analysis with Blackstone for most of my vehicles. It's $35 of value/entertainment.

Here's what they came back with most recently:
As you might imagine, we haven't seen many samples from these air-cooled 2.5L Steyer-Puch
engines over the years, and this is the first one where the interval on the oil was recorded in hours (34 hours).
Universal averages are based on ~3,500 miles of oil use, though, and it's nice to see most of the wear
metals in your sample reading lower than averages after what must have been a shorter oil change interval.
Chrome is the exception, and it comes from piston rings. If the rate of oil loss is stable, check back next oil
change to start building trends. No contamination was found.
The Chromium number was 4, vs. the "universal average" of 2. This batch was with Castrol 20W50 High Mileage, and the Zinc number was 637. They did not report any antifreeze contamination. :)

I'm on Rotella now....we'll see how the numbers come out in the future.

Re: Rotella users: T4 or T6?

Posted: Thu Jun 12, 2025 3:37 pm
by Czechsix
So did the numbers change drastically with the rotella change over?

Re: Rotella users: T4 or T6?

Posted: Sat Jun 14, 2025 2:32 am
by VinceAtReal4x4s
Seen the new Mobile 1 classic oil?

Re: Rotella users: T4 or T6?

Posted: Sat Jun 14, 2025 5:06 pm
by ChickenPinz
Yes! I'm waiting for the final assessment from this guy: https://youtu.be/a3uXSI9wQv8?si=1BEAXtu6UdUgOST9

He's reset my thinking on using Rotella in my older trucks: https://www.youtube.com/watch?v=HcJHJL5Ys-Y&t=757s
And here: https://www.hotrod.com/how-to/diesel-oi ... ine-engine

Science!

My fingers are crossed that this fancy M1 Classic might become my new "go-to" choice.

Re: Rotella users: T4 or T6?

Posted: Mon Jun 16, 2025 9:57 am
by whitesik
Interesting video, thanks! But all of it was discussing use in direct injection gasoline engines. How does that transfer to our older carbureted engine?

Re: Rotella users: T4 or T6?

Posted: Mon Jun 16, 2025 5:11 pm
by Czechsix
Anyone else using the Valvoline VR1 20w-50 solid lifter oil? I'm wondering how that compares?

Re: Rotella users: T4 or T6?

Posted: Tue Jun 17, 2025 8:53 am
by rmel
Yes, I have also used Valvoline VR1 Mineral but not Synthetic.
I do lean more toward Lucas Classic 20W50 mineral as I'll buy that in volume.
Both have about the same and appropriate levels of ZDDP for solid lifters.

I avoid synthetics for a couple of reasons. First syn or min I'll still change the
oil at 3,000 miles or W/I 1 year which ever comes first. So syn would be more
expensive. Second, the Pinz does burn a little oil by design. There are no seals
on the exhaust valve guides, which allows a little oil to weep down and aid in
cooling the exhaust valves. There are seals on the intakes.

Perhaps with more anecdotal evidence than solid data, given the higher
flashpoint of Syn over Min I want to avoid any build up in the chamber.
The R8X rotary community also seems to lean more toward mineral and
following the recommendation of Mazda.

Re: Rotella users: T4 or T6?

Posted: Wed Jun 18, 2025 7:05 pm
by Czechsix
Thanks for that reply. Agreed with the issues surrounding synthetic, I'll only run mineral oil in the old engines.

I'll be doing an oil change with the VR1, and at the end of the season I'll do an oil analysis to see what it's done. I might start another thread on that probably in the Haffy section.

Re: Rotella users: T4 or T6?

Posted: Thu Jun 19, 2025 6:11 pm
by ChickenPinz
I'll add in that piston aviation is still mineral-oil based -- no synthetic. And most all are pushrod engines.

Also, zinc levels were apparently reduced for increase compatibility with catalytic converters -- not an issue for our vehicles, so we could freely bump up the zinc.

Interesting (to me, at least), was the discussion of the role detergents play relative to the zinc, and how the former works against the latter. The argument was made that although those diesel oils have more zinc, the increased detergent levels knock that back down.

Re: Rotella users: T4 or T6?

Posted: Thu Jun 19, 2025 7:10 pm
by Czechsix
Yep

Ideally I'd like to run the ashless aviation stuff, like AeroShell 65 - basically an SAE30. Of course, when I wanted to use it, what happened? Shell stops making it. :lol:

I know some folks with VW's that are using the AeroShell products, and seem to be happy with it.

Re: Rotella users: T4 or T6?

Posted: Sat Jun 21, 2025 12:20 am
by ChickenPinz
I run Phillips 66 X/C aviation oil 20w50 in the plane and am tempted to do so in the Pinz, but simply haven't. I've looked for information about zinc content, and don't see any. The regular oil analysis widely varying numbers, so I don't know what to make of that. They range from 1 to 18ppm zinc.
Philips datasheet attached. I don't find any place they reference ZDDP or zinc.
If you're worried about cam wear, you could always add CamGuard.

Question for the masses: Has any Pinz owner ever had cam lobe wear issues, regardless of the oil they are running?
XC_AviationOil.pdf
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