The Stovebolt Site Forums The Shop Area Engine Shop Shell Rotella T4 - Zinc

As I read deeper and deeper into this issue it seems the controversy grows. I post this here for informational purposes as of today 10/21/22.

I reached out to Shell to inquire the amount of zinc in what’s most readily available in my area Rotella T4. Their response below:

“Hi,

Thank you for contacting Shell Technical.

The Shell Rotella T4 Triple Protection 15W-40 contains approximately 1200 ppm of zinc.

Hope this helps.”

I am asking if this value is consistent across the various weights.

Glad to hear this! I've been using Shell Rotella T4 15W-40 for the last few years on the advise of a stock car engine builder, when I was having lifter issues. He told me these older engines where designed to have zinc in the oil. He uses it for break in oil when he dinos. his race engines also.

I think that is higher than most oils but not quite the optimal amount as researched by the Classic Car Club of America. They produce their own brand of oil with 1600ppm ZDDP.

I've been using T4 for years but was recently told that they had reduced the amount of zinc in it. I believe it used to be around 1400ppm but I don't remember now. I'm glad to know you got the straight dope from the manufacturer.

Here is a link to purchase Classic Car Motor Oil and read more about ZDDP in oil if you wish.

https://inrccca.org/product/classic-car-motor-oil/

I’ll have to give the CCCoA a try.


Update from shell below after asking if that value is consistent across the weights if oil in the T4 line:

“ Hi,

Thank you for contacting Shell Technical.

You are correct except for two products, Shell Rotella T5 Ultra 10W-30 and Shell Rotella T6 Multi-Vehicle 5W-30.

Hope this helps.”

The reduction in ZDDP is for nearly all diesel rated oils (Rotella T4 is one) came about with the introduction of the API CK-4 rating. I have oil analyses that indicate that happened around 2018.

Shell reduced the ppm of ZDDP a few years ago. It was at one time 1600, then went to 1400 or so and now is 1200 (give or take...some weights are more like 1000ppm) I've read. There are better options if you want more ZDDP. Valvoline VR-1 still has 1400 last I checked and this should be plenty. There is one out there...Lucas Racing Oil I believe which has 2000ppm. At this point you may be flirting with too much and too much ZDDP will cause problems as your oil will become acidic and corrosive and you'll risk some serious damage.

I'm using Rotella T1 heavy duty SAE 30 Diesel Oil since years -no problems so far.

I have generally used 15w40 Rotella T4 in SBC engines that do not get exposed to starting conditions below freezing. I believe it is a pretty good formulation for flat tappet cam shafts but probably not as critical in newer roller tappet type engines. There are a number of tests conducted by oil formulators required to optain an API License (such as CK-4, or its predicessor CJ-4). For new engine build break-in I typically add an additive to boost the ZDDP as an insurance policy toward reducing flat tappet camshaft break-in concerns.

There is a lot of pressure on the oil indsutry to develop lower viscosity grades (10w30, 5w30, etc.) associated with improvements in engine fuel efficiency with engine manufacturers trying to ensure that those formulations will function in their engines (both current and previous designs).

Straight grades like SAE 30 are getting extremely rare and it is not clear how long they will remain in the market.

How about 0W-20? That's the lowest one I've seen in the store.

Singer Sewing Machine Oil.

I did some digging the other day on the Rotella stuff. Every formulation I saw had 1200+, as Jon states. I should have saved it, but I think one of the T6 formulations was more like 1300. I was surprised by that.

With the valve spring pressures of a stock inline six, 1000 ppm is more then enough to protect the cam and lifters. It's very likely you can get away with any oil you want. I have been running standard 10--30 in my 250 for years, going on 19000 miles now, but I have US made Rhoads lifters. The Rhoads are quality made but also bleed off at low rpm reducing the spring pressure even more.
Since the "oil issues " started back in '07 , I have yet to read where a stock engine has killed a camshaft or lifter that had been together for years. What you do read about is the new cams and off shore lifters, or the extreme lobe, thumper style cams going bad. Today it's off shore lifters, and no amount of additive or even luck, will keep them running.

Back in the late 50s when I began learning watchmaking one of the first things I discovered was how expensive specialty watch oil is. I couldn't afford even a small jar of it. One of the next things I learned is folks in the know would spray about 1 inch of WD-40 into a little jar (like a pimiento jar) and leave it alone for a week or two (it separates faster in cool weather). What one will get by doing that is two layers...a bottom layer (whitish and full of paraffins, propellants, fillers and various solvents) and a top layer which is nothing but a fine and light oil suitable for use in watch works, typewriters (was popular back then for that), musical instruments, electronic parts like variable resistors and tunable capacitors, guns, sewing machines...whatever. You can see it below. The top layer in that pimiento jar will lubricate possibly 1 million watches. And then in the 60s an older watchmaker explained why people generally don't like WD-40. His explanation? Most people pick up a can and immediately start spraying it, maybe shaking a little from side to side as they do or not shaking at all. Almost nobody mixes the stuff. So all they're spraying out is the junk at the bottom and when that's gone, all they're doing is spraying a fine light oil on things. And if you watch people use WD-40, I believe he was right. Good luck.

I did my most recent oil change with Castrol 20w-50 Classic high zinc oil. I didn't look at the jug to see what the zinc was in ppm but I will next time.

[img]https://ausfahrt.smugmug.com/ManCave/1963-Chevy-C10/i-dWB93W5/A[/img]

Any chemists? I know of at least one out there.

Here's a "Molecule of the Week" from the American Chemical Society.

Molecule of the Week
.
.

A couple weeks ago I had emailed Mobil tech support to ask about ZDDP levels in there 15w-40 Delvac. That stuff is pretty consistently the cheapest 15w40 I can buy.

Got some weird response that their marketing department didn’t want to release that detail to “protect their data sheet.”

That's really weird. Their data sheet doesn't tell you that info anyway. Most oil data sheets that I have seen don't have that information.

I think you could get that info from Blackstone Labs, who had probably done an oil analysis (unused) on most of the oils on the market. If they haven't, a guy could spend $25 and send them a sample of virgin oil. The used oil analysis would still be pretty close on additives, as most aren't "used up".

"
MOBIL DELVAC 1630 30wt HIGH ZINC, 1400ppm ZDDP, MOTOR OIL, 55 Gallon Drum. Mobil Delvac 1630, 1640, and 1650 are high performance monograde diesel engine oils formulated from advanced technology base oils and a balanced additive system."


Do a web search on "mobil 15w-40 Delvac ZDDP"