Delo 100 vs Delo 400 in Yanmar 4JH-DTE

[Microship]

HI folks...

Been going through the oil-change trauma (only so because it took me ages to figure out that the two tanks in my oil-changing system had closed-off vent hoses buried deep under the galley stove, leading to incomplete pump-outs and meaningless data from the associated Tank-Tender channels). I popped down to the local NAPA and asked for three gallons of DELO 400, then noticed just as I was about to pour it in that he gave me DELO 100. I hit the *pause* button.

Researching since, I find that it is not at all clear-cut, and that the DD folks say the 100 is way better for their particular breed of engines. I have no idea whether to extrapolate this to the Yanmar; I already put 400 in my 3GM genset, and it is what I have been running in the 77-HP turbo main.

I thought it likely that someone here would know... take back the 100 for a swap, or use it?

Many thanks, and cheers from Nomadness (moving this month to Friday Harbor!)

Steve

[xymotic]

It's not like the motor will sieze if you use the not-perfect oil. My oppinion on oil is that it's better to have clean oil than the exactly perfect oil for the application. I will mix weights or brands without giving it a lot of thought. As long as it's clean.

[delmarrey]

The 400 is a synthetic.>>> Engine Oils, Synthetic Motor Oil, Delo 400 LE, SAE 15W-40 - Delo - (United States)

[Microship]

Interesting... I wonder why the Delo site does not mention 100 under Engine Oils? That's kind of bizarre...

I don't know the trade-offs between synthetic and non-synthetic... I know people get very analytical about all this, including the oil analysis, and I've seen threads with exhaustive near-religious battles over oil type. I guess I just need a nudge in one direction or the other. The engine is turbo, and was made circa 1987... with 3137 hours on the odo...

(Same sense of bewilderment re ATF... mine was about 200 ml down, and some digging in the shop manual revealed they prefer Dexron. You ever research that stuff? Even the Wikipedia page is fascinating...)

Many thanks!
Steve

[delmarrey]

You do want to use the HD oils for diesel due to the extreme pressure on the crank bearings. I use the Valvoline Premium Blue but there are several brands out there. Here's some good reading on oils, if you can sit that long. >>> Car Bibles : The Engine Oil Bible

Originally Posted by from page 2

Diesel engines run much higher compression ratios than petrol engines and they run a lot hotter, so the oil is formulated to deal with this. Plus they produce a lot more dirt in terms of combustion by-products. Diesel-rated oils typically have more detergents in them to deal with this (see Using Diesel oil for flushing above). It's not unheard of for diesel oils to clean a petrol engine so well that it loses compression. Diesel-rated oils also have an anti-foaming agent in them which is unique to diesel engines, and not needed in petrol engines.
So is that the be-all and end-all answer? Well not really and that's why this is a difficult question to give a straight answer to. The above statement is more relevant to commercial diesel engines. Nowadays, just about all passenger car / light commercial oils (including OEM ones designed for both petrol and diesel engines) will carry the ACEA A and B specifications. ie. formulated to satisfy the requirements for both types of engine. So just because the oil is labelled "Diesel" doesn't mean it's not suitable for petrol engines - it will more than likely carry an ACEA A3 / OEM petrol spec as well.
However you do need to be a bit careful regarding choosing the right diesel spec - if you have a modern common rail / direct injection diesel, chances are it will require at least an ACEA B4 spec to cope with the higher piston temperatures that can cause piston deposits (and stuck rings). ACEA B4 is fine where B3 is recommended.

Read more: Car Bibles : The Engine Oil Bible

As for the ATF's. The Dexron IV is the highest in mineral based now but the Dexron VI is another synthetic.

[SearenitySail]

I only use Delo 400 in my 2GM20F.

2600 hours and no problems.

[Microship]

I thought I might have just stumbled upon a set of answers here (a PMY column), but it's like a medical advice site... good discussion but carefully non-committal with lots of "ask your engine manufacturer." But the more I read, the more it seems like it matters... my 1987 Yanmar book just says 1-D or 2-D diesel oil. I've been using 400 SAE30 since I've owned the boat (4 years) and have been *cough* bad about end-of-season changes. There are some low-speed smoking issues, and one site says that synthetics (400) reduce this.

I never would have even batted an eye without the accidental purchase of 100... this is why I like electronics more than engines! <wry grin>

(On the ATF topic, the misinformation and confusion out there is staggering. My Yanmar manual says Dexron, but LOTS of people on forums say to just use engine oil. This seems like a potentially important topic, but the power of anecdotal evidence is high and everyone has stories. All quite maddening... I topped mine off with Dexron III.)

Thanks for the thoughts, folks... seems my engine questions here are always either of the traumatic or n00b variety. One of these days it will be old hat, I suppose. (I'm the guy who had the oil-change nightmare a couple of years ago involving an incorrect Fram that the PO had put on, crossing that to another brand, then discovering from gasket incompatibility and 2 gallons of oil blasted into the bilge upon power-up that the original filter had been the wrong one... at least now I'm using all-Yanmar filters!)

Steve

[Microship]

Follow up: I returned the Delo 100 and bought Delo 400 (SAE 30), after reading that the latter is formulated for 4-stroke diesels and the former for 2-stroke. Whether this is true or relevant, I have no idea, so if you stumbled across this via Google please don't take it as authoritative. I'm just sticking with what I've been using, reinforced by comments here and elsewhere.

Thanks!
Steve