So what is the latest consensus on 15w-40?

[Tdub]

Sorry if I am starting a new thread on this topic. A couple months ago it seemed that using 15w-40 Rotella was a bad idea. Over the life of my 2004 SN Excaliber I never paid attention to detailed specs, I just always used 15w-40. Some years it may have been Valvoline, some years Rotella. As long as it was 15w-40, that is what I used. So what is the final verdict on this topic. I am about ready for an oil change. Any insight will be appreciated.

Thanks.

[oldjeep]

Use an oil that meets whatever specs your manual says. For me that means I will use Delo sde 400 15w40 since it meets the specs in my manual and Rotella doesn't anymore.

 

[JGray]

I will look I found some Rottela semi synthetic that met all the specs. Not at home now but will verify but think it was the T5.

[sunvalleylaw]

I ended up deciding not to change out the Rotella mid-season, but will just go with the Delo next time.

[John Brooks]

I followed @oldjeep and used the Delco. Was also a great price on Amazon. Thanks.

[xrated]

Costco had 3 gallons of Delo 400LE for 30 bucks. SM rated.

 

Plan on getting another 3 gallons next time we go if they still have it.

[jeromezz430]

Personally i use 15w40 from any premium brand aviable in France (elf,total,castrol,...) and i add ZZDP additive in oil to prevent camshaft/lifter wear.

But it's for an old Ford 351w without hydraulic roller lifter.

[Tdub]

I was looking at my manual last night and the only spec I saw was 15w-40 SJ. (2004 SN 196 Excaliber) So SJ is no longer available? But SN will be OK?

[skiinxs]

The higher letters are backward compatible. They just meet more stringent spec's. (Other than the solid lifter issue with the 351 Ford)

[Tdub]

Thanks to all. Delo it is.

[LeonL]

Posed the question about Rotella not having a gasoline engine spec to the manager of a large auto parts store. The have a rather large fleet of vehicles and have always used Rotella. He said they are continuing to use it. I guess he doesn't have to repair out of his pocket though. I may go to Delo at that price if my local Costco has it. Most recently I've been using Mobil Delvac at $12.99 a gallon.

[oldjeep]

Fwiw, the Delo is still around $12.50 a gallon on Amazon prime. Their quarts are over priced though so I buy them from Walmart for around $3.50. (My indmar takes 5.5 quarts and I hate having partial gallons sitting around)

[Edmund]

I use 40w Valvoline VR1 Racing oil in my 1998 GT-40. It contains a high zinc level. Even though Valvoline's headquarters are located here in Lexington, that particular oil is difficult to find on shelves around here. So I buy it online, usually through Amazon.

[sunvalleylaw]

@oldjeep , yeah thanks for that in the other thread. The Delo is in my Amazon cart for the end of this year. The only other thing I will add, is that in the other thread, I got the impression the issue with the backward compliance had to do with catalytic converters, which I don't have on my older Malibu Response. But I am no mechanic, so I would not rely on my impression. But bottom line, it was not necessary for me to replace the oil I had just changed in until after this season as per normal, but going forward, best to stick with mfr. specs as per the updated manual. (my manual originally called for 20/50). And the Delo qualifies with the updated specs. Therefore, Delo.

 

Here is a link to that thread if anyone wants to read through it to draw their own conclusions: Rotella No Longer Qualifies

[skierjp]

15-50 Mobile 1 synthetic

[jetpilotg4]

Skip Dunlap Whats your take on this?

[EricKelley]

I am not an oil chemist, but I think you have to be careful with the high Zinc oils with engines with cats. It is supposed to cause premature failure of them. I am a big fan of the high ZDDP oils in all my stuff without cats. Mobil 1 15w50 in my 200 6L.

[skierjp]

@"Eric Kelley" agree

[vtjc]

Another year has passed since this thread was active. It’s close to winterization and oil change time for me. I have a new to me 2008 PCM Excalibur 343, original oil specs SAE 15W-40 GF-4/SM. Following links Jody provided in the Warning - Shell Rotella no longer has gasoline engine designation thread it seems GF-5 can be used where GF-4 is recommended. Can SN can be used where SM is recommended?

What oils are people finding that meet these specs? Valvoline VR1 or Chevron Delo?

[Ski_Dad]

Delo will definitely work fine. All the 15w40's are good.

[Alberto Soares]

API SN is better than SM, the greater the second letter better the oil

[oldjeep]

Yes, sn can be used in place of sm

[BraceMaker]

So oil is one of those things. The updated spec is supposed to meet or exceed the previous spec. But it doesnt mean it is necessarily the same. Should be fine.

[BrennanKMN]

Ever since Rotella lost the SN rating I just go to the store and get whatever 15w40 diesel oil they have with an SN/SM rating. I am not running long enough drain intervals for it to really matter, so I don't care.

 

I've been doing oil analysis on my truck for years. Thinking I might do one on my boat this fall. It's always fun to see the actual data.

[Zman]

Same as @oldjeep and others with the Delo SDE for 2 years now. Good stuff.

Walmart has the 2-1/2 gallon jugs for 28 bucks. Great deal for 2 oil changes.

Changing oil every 50 hours I don't waste money on synthetic.

[Ed_Johnson]

For 15 years I have been using Royal Purple 15W40, both oil and filter. I had a friend who started using it in his Tug Boats years a go, and went from 1000 hr. engine changes, to 2000 hr. Swore it was the best oil ever. Only problem is they seem to have stop making 15W40. Can't find it any where. At a loss now as to what is the best Synthetic Oil. Use to use Mobil One, but they changed the formula, and at the time, my boat didn't even want to idle without quitting, That was when I switched to Royal Purple. My choces now seem to be 10W30 or 5W50. Which would be better?

 

 

 

[DW]

@Ed_Johnson : How many hours are on your engine? Low hours I would go with the 30 wt. if high hours and you see lower oil pressures at idle, go with the 50 wt. The 5 and 10 viscosity numbers are cold temp numbers which is not really a big issue on a boat, either is fine. I ran 5W-30 Mobil 1 for many hours, it was at the 1k hour mark I upped the viscosity and ran 0W-40 to get back some idle oil pressure. Boat sees slalom and footing speeds.

[RichardDoane]

@Ed_Johnson , Jegs Performance has RP 15w40, as do many others when I just googled it

[blakeyates]

Since my profession is lubricant sales, I’ll add some general comments to this thread: API (American Petroleum Institute) SN is the latest spec for gasoline engines; then you choose the 15W-40 viscosity. Since ski boats idle too much and throttle too much, both create fuel dilution even in the latest engines. Fuel dilution in the crankcase pulls the oil’s viscosity down, thus don’t use anything lighter in vis than a 15W-40 unless maybe a synthetic 5W-50 that meets API SN. To summarize, no 10W-30, 5W-30, or 0W-30. Last, I’m not sure if all synthetics do well with the chemical mixtures of fuel with their base oils, additives, etc. That said, ski boats are not a good place to push for extended drains. Change it at 50 hours.............engines aren’t cheap. I have an oil analysis from my 2017 Nautique. I’ll look it up and try to post it in a later thread.

[DW]

FYI - Oil analysis done on my 50 hour oil drain interval @ 1000 hrs did not show fuel dilution problems, but that is only a one point data sample and I do not spend much time at idle compared to others so take it FWIW. Also, no indication of any fuel diluted effects noted in the data. Good policy to follow oil viz recommendations by mfg and since the 40wt is still available, a good option.

[eleeski]

In the real world where boats sit for 6 months, are in extraordinarily humid environments corroding everything, run cooler than the automotive applications they were designed for, are subject to overheating from seaweed or impeller failure, prone to rodent damage and a multitude of other unique challenges in marine use, has anybody ever had a failure due to the oil? Seriously, even if the "wrong" oil causes a failure 10% earlier, if you make it to 3500 hours instead of 4000 hours you have scored! And something else was about to break before 4000 anyway.

 

Take care of what matters. Keep the oil full and clean. Go ski.

 

Eric

[Bdecker]

I run RP 15w/40 in our CarbonPro. Amazon brings it right to my door. Running Duralec 15w/40 in my 05 Mastercraft. Typically that boat gets less than 50 hours per season.

[Jmoski]

I switched to delo 15w-40, but for those that put rotella in the formula didn’t change so I wouldn’t sweat it.

 

There used to be an exception to allow heavy duty oils with CJ-4 ratings to certify as SN (automotive) where they didn’t meet the phosphorus content limits for cars. That exception/waiver was removed...

[sunvalleylaw]

@Jmoski Season before last, I had done my oil change with the Rotella right before I found out the certification had changed. I left it and it did fine. Oil stayed clean and full. Next time I did Delo. Will probably just go get Delo today and my Wix filter, and get it all done, as it is a rainy day, and I might as well get it done today. We are starting to get near freezing at 5-6 in the morning, and looks like we aren't getting out any more this year.

[A_B]

I usually find the standard Rotella 15W-40 but I like to run synthetic and can usually only find 10W-40, so that’s what she gets.

 

30+ years ago a motor head friend of mine told me after a season of running his high performance boat, he found on his usual end of summer year tear down that the valves and everything else looked like new on synthetic vs standard racing oil. I’ve run synthetic in everything I own since.

[eleeski]

@A_B Who tears down your boat engine at the end of the season? Something way more than the oil is wrong if you have to do that.

 

Anyone remember Raylube?

 

Eric

[A_B]

@eleeski my friend had various go fast bots and eventually a Fountain 41 and is just a need for speed kind of a guy. He worked his engines over every year adding more horsepower. He even has a Z06 Vette that is running like 1500HP. He and his son have a 23’ I//O that runs around 130mph.

 

He told me the valves and internals look like new on synthetic and no matter how many times he changed regular oil, he had carbon buildup. That was enough for me to hear. This guy knows his stuff.

[skierjp]

Mobile 1, 15-50 and I always change it before 50 hours.

10 hours on the first factory oil, 25 on the next oil change then every 50.

At the end of the year it goes back to the factory and sold to some lucky skier??