Thanks alot for the opinions fellas.

I wasn't really sure what oils had the necessary Zinc. I run 15w-50 Mobile 1 in my 04 Hemi Ram. If it has the protection I need for my solid lifters then I will run it in the slant also.

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1966 Dart GT
1965 Barracuda

That's a really thick oil to be running in such a new engine. Why? It's costing you fuel economy and hastening engine wear. Thicker oil does not mean better protection, it means slower lubrication on engine startup.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

What do you reccomend? I know squat about oil.
Keep in mind it is really hot down here.

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1966 Dart GT
1965 Barracuda

I'd stick with the viscosity recommended in the owner's manual. It's probably even on the oil cap. I don't believe your '04 doesn't have the MDS does it? The MDS equipped engines use 5W-20. Without the MDS I'd use Mobile 1 0W-30 or 5W-30. You don't need a lot of zinc and phosphorous in your engine as there are very few surfaces that slide against each other.

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Joshua

Not sure, but wouldn't an 04 Hemi be a roller cam, roller rocker engine? If I understand correctly the "roller" engines needs much less zinc in its oil.

I run 5w30 Valvoline dino (it is free) oil in just about all my vehicles including my slant, though now that the rings should be seated good (20k miles) I may run either Shell or Mobil 1 full synthetic, prolly 10w30. I always heard run 1 step heavier syn then dino.

The wife's 98 Toyo Taco runs Mobil 1 in the engine, 5 speed trans, and rear. Picked up 1~1.5mpg, but she runs it because she is a Ryan Newman fan, and they were his sponsor up till this year.


TopHat

Tophat,
I think that is an old wive's tail.

SL6 Dan suggested I try the 0-30W Mobile 1 and must say that I am pleasantly surprised.
The 0-30W builds pressure faster than any oil I have ever used. The engine is also much quieter.

I did a test and went back to 10-30 Mobil 1 and was shocked at the difference! Even compared to 5W-30 there is a big difference. The bright green capped (0-30W) Mobil 1 oil is an interesting formulation.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I think so too. I also think it's amazing how much of this kind of baseless, fact-free nonsense gets pulled out of thin air (or wherever it might be pulled out of) by dillweeds who don't have the slightest clue what they're talking about, but still want people to take their advice. I'm not saying either of you (Tophat or Ted) or anyone else on this board fits in that category — I'm talking about whoever told it to you, and whoever told it to him, and whoever told it to that person, and…

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Ted and Dan, it very well may be "an old wife's tale" as I have no hard evidence or data on the subject. I had heard it from an alleged respected oil company rep many years ago and took it for fact, and never had anyone dispute it till now. I have not run syn in too many of my engines, mostly due to cost and leaks, and the fact I get dino oil for free.


TopHat

I found this in the Tech section.

Modern engine oils in older engines: Addressing the additive issue

The problem

Zinc and Phosphorus-based extreme-pressure additives known generally as ZDDP have been present in engine oils for many years. Even in minuscule doses, these additives affect the hypersensitive exhaust catalysts used in current ultra-super-mega-low-emission vehicles. These extreme-pressure additives are also, so goes the claim, unnecessary in engines with roller-type valve lifters (i.e., virtually all of them today), which eliminate the sliding-friction junction of camshaft and solid non-roller lifter, which was what the ZDDP was used to lubricate/cushion. The latest API oil service rating for gasoline engines is "SM". The SM standard limits ZDDP to concentrations lower than optimal for our older engines, meaning these new oils give significantly poorer protection of the solid lifter-to-camshaft junction compared to previous spec oils. In everyday terms, the latest engine oils are not slippery enough when it comes to the camshaft-tappet junction.

Some of the heavy duty (diesel-rated) oils are good, but even many of these are moving to the SM service rating. It is only going to get more difficult with time to find SL-rated oils that contain the higher levels of ZDDP.

The solution

Generally, it's a poor idea to pour oil additives or "engine treatments" into your crankcase. Most of them do no good, and many of them can actually do quite a bit of damage. However, the low-ZDDP problem can be addressed successfully and at low cost if the additive is chosen carefully and used in thoughtful proportion. The ZDDP additives are available in the aftermarket. GM offers it as "EOS" (Engine Oil Supplement) under p/n 1052367 in the US, 992869 in Canada, and it seems adding some at each oil change would provide the extreme-pressure protection missing in SM oils without much of any chemical incompatibility risk, and without buying more costly exotic oils.

How much to add?

Well, the SM spec stipulates Zinc and Phosphorus content of 0.06% to 0.08% (600 to 800 ppm). GM EOS contains 5762ppm Zn, and 6221ppm P, or 0.6%. That means in a quart of EOS, you've got about 0.192 ounce of Zn and P. It's been well documented that a 0.10% to 0.12% concentration of Zn and P is optimal for flat-tappet engines, for example in SAE papers 770087, 831760, and 2004-01-2986.

To achieve 0.11% Zn and P in a 5-quart system, we would want 0.176 ounces of Zn and P. There's 0.192 ounce in a quart of EOS, but there's also 0.08% Zn and P in a quart of SM engine oil (actually, most of them run a little on the high side, as it seems, but we'll use the 800 figure). In 5 quarts of SM engine oil, therefore, you've got 0.128 ounce of Zn and P. Therefore, you're a little under 0.05 ounce short of what you want. Doing out the math and remembering that I've been rounding pessimistically, 8 ounces (1 cup, i.e., half a pint) of EOS would bring most any SM engine oil back within the optimal Zn and P content, which means that a quart of EOS would last you four oil changes. A quart of EOS lists for over $9, but can be had for $5.50 or so from a friendly parts department or GM Parts Direct. So, the added cost per oil change would be less than $2, even allowing for shipping charges.

So-called oil "stabilizers" (STP, Lucas, etc.) are mostly just motor snot, the kind that sleazy used-car dealers have been spooning into crankcases to quiet worn engines and temporarily stop exhaust smoke since your grandfather was in the market for his first car. See here for the real story on the damage these "stabilizers" do.

Most of the data for this article comes from the tables and charts here.

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1966 Dart GT
1965 Barracuda