New Castrol oil for the classics! "Castrol GTX Classic" 20W-50

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Would this motor oil work great in my old 1939 dodge truck? And the same for my 48 Ford F1, 53 F2, 66 inline six mustang (I think the mustang could run anything but just asking)
The flat heads are what I'm more worried about and we may get another purchase of 2 more down the road...
 
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Would this motor oil work great in my old 1939 dodge truck? And the same for my 48 Ford F1, 53 F2, 66 inline six mustang (I think the mustang could run anything but just asking)
The flat heads are what I'm more worried about and we may get another purchase of 2 more down the road...
Those vehicles likely used 30w when new. 20w50 might be just the ticket.
FYI, I have used the older Rotella T 15w40 in my classics. I will use the Castrol going forward.
 
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That 1930s engine will run fine on anything, the best thing to compare them to is probably a modern small engine, they're low compression, low revving, I'm sure the cam isn't very aggressive on lift and the springs aren't that firm, remember those things were designed to run on fuel that makes modern 84 octane gas look like premium. The oil back then was probably non-detergent with very little additives maybe an antifoaming agent but it would've been comperable to what we'd classify as API SA and API SB these days. Any Xw30 oil should be fine in those old engines, and you don't need a ton of zinc.
 

SR5

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How's the current Zinc content of today's Rotella 15W-40?
Here is a 2020 VOA from PQIA for the API CK-4 rated Rotella T5 15W40 semi-synthetic, it shows 1267 ppm zinc, 65 ppm Moly, 130 ppm Boron with a TBN of 9.25 and a KV100 = 14.6 cSt.

The detergent package is a more modern Ca (1905 ppm) + Mg (438 ppm) mix, rather than an old school Ca only package.

What I also like about it, is that the -20C cold cranking tested to almost 6000 cP (with 7000 cP being the maximum permissible under J300) so it’s at the top end of a 15Wx oil, meaning a heavy base oil was used, with the associated benefits for shear stability and low Noack volatility.

All up it looks great to me.

 

SR5

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How's the current Zinc content of today's Rotella 15W-40?
This is the other one for you, also from PQIA, also from 2020, Shell Rotella T4 SAE 15W-40 mineral, it’s also API CK-4

Zn = 1130 ppm
Boron = 198 ppm
KV100 = 14.9 cSt
TBN = 9.32 , but as a more traditional Ca (2327 ppm) heavy package, still fine for non-TDI (turbo direct injection) applications.

 
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Neat to see. I remember back in '87 running Castrol 10w30 in nearly an identical colored bottle in my mustang GT. At the time Castrol was considered something near exotic vs the normal pennzoil and the like.
 
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Since this is the about same price as the Supertech Full Syn V-twin oil which also only claims API SL, but is full syn and contains around 1100ppm of phos, according to the datasheet a forum member got from Warren, I'd probably use it over this Castrol conventional oil.
1628952889820.jpg
 
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Forgive me if this is already posted (I checked but didn't see any posts about it). I was at my local Walmart looking for a U1 battery for my new-to-me mower, and of course I had to walk the oil aisle. This caught my eye, and I've never seen it before:

....
I think this is fantastic for those who have been struggling to find a high ZDDP oil for their classics. It is ONLY offered in 20W-50. Obviously this isn't for the thin crowd, but what does everyone think?
Too thick for many factory performance engines from the 6o's and early 7o's.

There has always been 10w40 and 20W50 high ZDDP stuff out there. Think marketed for Motorbike oil.

let me know if you find any 10W30 dino at a reasonable price!

I think most of this flavour got pulled to keep high phos out of modern engines with post treatment. I didnt see a memo though.

OilMagnate, thanks for posting anyhow!
 

SR5

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For those looking for a high ZDDP 10W30 here is a VOA for Shell Rotella T5 10W30, that gives 1340 ppm zinc, and it’s a high HTHS 30 grade. I think it would work well in an old school flat tappet gas engine. I‘m sure a modern HDEO Diesel engine oil, is higher quality and better tested than most of the regular gas engine oils used back in the 60’s or 70’s. Not long ago they were all dual rated, for gas and Diesel engines, this is more restrictive under the most recent API rules, but they are still commonly used in gas engine motorcycles without issue.

It doesn’t have to be Shell Rotella, you could also looks at Delo or Delvac etc.

 
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For those looking for a high ZDDP 10W30 here is a VOA for Shell Rotella T5 10W30, that gives 1340 ppm zinc, and it’s a high HTHS 30 grade. I think it would work well in an old school flat tappet gas engine. I‘m sure a modern HDEO Diesel engine oil, is higher quality and better tested than most of the regular gas engine oils used back in the 60’s or 70’s. Not long ago they were all dual rated, for gas and Diesel engines, this is more restrictive under the most recent API rules, but they are still commonly used in gas engine motorcycles without issue.

It doesn’t have to be Shell Rotella, you could also looks at Delo or Delvac etc.

In this VOA from last year it looks like there's less phos than that, in fact the 10W30 seems to only have around 1000ppm according to that VOA, but then again, it's Blackstone so it may be a little off, the typical Rotella package is 1100ppm of phos, so I'm a little thrown off by the VOA with only 1000ppm and the UOA with almost 1200ppm, but perhaps the UOA it picked up phos from the previous oil or deposits in the engine or something.
 

SR5

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In this VOA from last year it looks like there's less phos than that, in fact the 10W30 seems to only have around 1000ppm according to that VOA, but then again, it's Blackstone so it may be a little off, the typical Rotella package is 1100ppm of phos, so I'm a little thrown off by the VOA with only 1000ppm and the UOA with almost 1200ppm, but perhaps the UOA it picked up phos from the previous oil or deposits in the engine or something.
Thanks for that, interesting. I’ll list them out, just to have them in one place.

2020 VOA
Rotella T5 15W40
Phos = 1068 ppm
Zinc = 1198 ppm

Rotella T5 10W30
Phos = 989 ppm
Zinc = 1085 ppm

2020 UOA
Rotella T5 10W30
Phos = 1159 ppm
Zinc = 1342 ppm

Castrol GTX Classic 20W-50 from PDS
Phos = 1200 ppm
Zinc = 1300 ppm

For me, if I‘m looking for a high zinc oil, I like to see 1000ppm Zn or above.
 

Jackson_Slugger

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I think at one time Castrol SYNTEC 5W-50 was a "classic car" oil, but it doesn't seem like they market it as such anymore...
 
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Here is a 2020 VOA from PQIA for the API CK-4 rated Rotella T5 15W40 semi-synthetic, it shows 1267 ppm zinc, 65 ppm Moly, 130 ppm Boron with a TBN of 9.25 and a KV100 = 14.6 cSt.

The detergent package is a more modern Ca (1905 ppm) + Mg (438 ppm) mix, rather than an old school Ca only package.

What I also like about it, is that the -20C cold cranking tested to almost 6000 cP (with 7000 cP being the maximum permissible under J300) so it’s at the top end of a 15Wx oil, meaning a heavy base oil was used, with the associated benefits for shear stability and low Noack volatility.

All up it looks great to me.

Too bad it no longer carries a gas rating or I'd be running it all summer.
 

SR5

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Too bad it no longer carries a gas rating or I'd be running it all summer.
Yeah, the SN is gone, but that has more to do with API no longer allowing a dual rated oil with high ZDDP as a loophole. I personally would have no concerns still using it in either application. But YMMV.

For the record Rotella T4 15W40, T6 15W40 and T6 5W40 are still all JASO MA/ MA2 rated, for motorcycles. Last time I looked, there weren't many diesel motorcycles for sale.

(Not fighting, just chatting).
 
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Too bad it no longer carries a gas rating or I'd be running it all summer.
I ran it when it came out when I couldn't find the classic conventional Triple Protect 10W30.
It wasn't a good oil. I am sure it was adequate for many, but it wasn't special.
Special oils were (in no particular order)

Quaker State Higher Mileage Engine with Slick 50

Pennzoil Bronze bottle Semi-Synthetic.

Rotella Triple Protect 10W30 conventional

Formula Shell API SL/SM

Mobil 1 Racing 4T (original real synthetic formula)

Mobil Clean 5000 API SL/SM
 
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Yeah, the SN is gone, but that has more to do with API no longer allowing a dual rated oil with high ZDDP as a loophole. I personally would have no concerns still using it in either application. But YMMV.

For the record Rotella T4 15W40, T6 15W40 and T6 5W40 are still all JASO MA/ MA2 rated, for motorcycles. Last time I looked, there weren't many diesel motorcycles for sale.

(Not fighting, just chatting).
I figured as much. I might still give it a run if it goes on sale.
 
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