2gm20f factory oil rec. not found anymore

[Jared1048]

I have a 2gm20f circa 1985. In the manual it says to use Shell Rotella 20 wt for temps between 50-70 degrees. Problem is I can't find Shell Rotella 20w anywhere. I have been using the rotella 30wt but now that the temps are dropping id like to be using the right oil. I haven't been able to find any straight 20 wt oil for that matter. Most have moved to multi wt synthetics.
what oil should I use on my older yanmar 2gm20f? Is there an updated manual that shows new oils to use that are better? 25 yo manual probably isn't current

Thanks,
Jared

 

[Joe]

Have you tried calling your local Yanmar marine service center? They should be happy to give you that updated information.

 

[Steve Dion]

They have been recommending multi weight oil for years. Contact the distributor and ask them.

I never saw Rotella recommended only Yanmar oil.

 

[seadaddler]

15-40

I have been using Rotella 15-40 since the boat was new 2007 and I think that is what most are using.
nick

 

[kloudie1]

Jared, the original Yanmar engine shop manual recommends Mobil Delvac 20-40 for your engine. The newer oils are 15-40 and Delvac is available at Wal Mart .. Shell Rotella T 15-40 is equivalent diesel engine lube oil and is used a lot by Yanmar engine owners. Probably not a good idea to use a synthetic..

 

[Claude L.-Auger]

Ditto for the Shell Rotella T 15W-40 1 on my 3GM30F. Also available at Walmart.

 

[fireman416]

I run the Rotela 15/40 on my Yanmar and aslo on an old MGB 4 banger. It is a good oil for hard working little engines...

 

[Jared1048]

http://www.google.com/url?q=http://...EQFjAC&usg=AFQjCNHWW32CMdcZjjdmAzB2WE4iC8hRcQ

see the oil recommendations.

I'll get some Rotella T 15-40 and use the left over straight 30 when I'm in Mexico.

Thanks!
Jared

 

[Benny17441]

I know somebody who is hoarding a cache of Rotella 20 weight. Strictly under the table stuff but guaranteed 1983 vintage. Pardon the pun, no harm intended but the oils have progressed immensely in the past 30 years. Like others have recommended a good 15W-40 will outperform the vintage Rotella at any temperature. Manufacturers update their recommendations from time to time and its is prudent for us to keep current.

 

[Jared1048]

Cool so we have consensus.

Now do we want "regular" or synthetic?

 

[Charles Erwin]

Jared

As Klodie says in #5 above avoid the synthetic. Suggest Rotella T 15W40 in the Yanmar 2GM20F and any earlier series motor.

Use your straight 30 in your transmission.

Charles

 

[Benny17441]

The reality is that regular oils and synthetic oils both offer the same engine protection. In a combustion engine both oils get contaminated with combustion by-products, intake dirt, and unburned fuel at the same rate. We tend to change our oil at preset intervals so why pay considerably more for the same protection. Now you use synthetic oil in a clean enclosed space like a transmission with few contaminants and it will last a lifetime. Another factor is that some with older engines and transmissions have reported a larger incidence of oil leaks as perhaps the old gaskets and seals do not work that well with the synthetic oils. Your boat, your choice. My personal choice, regular oil changed every six months.