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MW

Martin_WJ@prodigy.net

Thu, Feb 28, 2002 2:34 AM

We have Perkins 6.3544 turbo charged engines which are about 18 years old,
and a Westerbeke generator. The previous owner used straight 40 weight oil
in them. The owner's manual for the Perkins specifies that the oil should
meet some 18 year old mil-spec which is probably no longer extant (for that
matter, I don't know if that's a U.S. or British mil spec), and fails to
specify any API rating. It does however specify that the oil should be
straight 30 weight or a 20W/40 multi weight and gives a few examples (e.g.
Rotella TX). I don't really know why the previous owner was using straight
40 weight though -- if he neglected to read the manual, or whether he knew
something that I don't.

After looking around some, it seems that the diesel oils commonly available
now (in Florida at least) are 15W/40 with API ratings of CH-4, CG-4, CF-4
-- not 20W/40 and not single 30 weight.

My assumption is that these modern 15W/40 oils are superior to those
actually specified for the engine 18 years ago, and are entirely
appropriate to use now, but I'm reluctant to diverge from the spec without
inquiring first. Anyone have a reason that I should not just go with the
current 15W/40 API CH-4 products from Shell, Chevron or Mobil?

Thanks.

Bill Martin
Telegraph Hill

We have Perkins 6.3544 turbo charged engines which are about 18 years old, and a Westerbeke generator. The previous owner used straight 40 weight oil in them. The owner's manual for the Perkins specifies that the oil should meet some 18 year old mil-spec which is probably no longer extant (for that matter, I don't know if that's a U.S. or British mil spec), and fails to specify any API rating. It does however specify that the oil should be straight 30 weight or a 20W/40 multi weight and gives a few examples (e.g. Rotella TX). I don't really know why the previous owner was using straight 40 weight though -- if he neglected to read the manual, or whether he knew something that I don't. After looking around some, it seems that the diesel oils commonly available now (in Florida at least) are 15W/40 with API ratings of CH-4, CG-4, CF-4 -- not 20W/40 and not single 30 weight. My assumption is that these modern 15W/40 oils are superior to those actually specified for the engine 18 years ago, and are entirely appropriate to use now, but I'm reluctant to diverge from the spec without inquiring first. Anyone have a reason that I should not just go with the current 15W/40 API CH-4 products from Shell, Chevron or Mobil? Thanks. Bill Martin Telegraph Hill

A

alexh@olypen.com

Thu, Feb 28, 2002 7:16 AM

----- Original Message -----
From: "Bill Martin" Martin_WJ@prodigy.net

After looking around some, it seems that the diesel oils commonly

available

now (in Florida at least) are 15W/40 with API ratings of CH-4, CG-4, CF-4
-- not 20W/40 and not single 30 weight.

Hi Bill,

Not to worry, you'll be fine with 15w40 oil. 30 weight is perfectly OK as a
second choice and 40 weight probably won't really hurt anything (especially
in Florida heat). The main drawback to using heavier oils (like 40wt) is
that, at start-up, it takes longer for the oil to get from the oil pan to
where it's needed. In colder climates using a 40wt or even a 30wt can also
cause sl-o-o-o-o-w cranking but that's probably not a big problem in Florida
<G>.

Now for a bit of oil trivia: For a long time there really was no such thing
as 15w40. The SAE sets the standards for motor oil viscosity and they didn't
actually have a standard for 15w40. What they had was a standard for 20w40
and a rule that said something like "If your 20w40 has a low enough low
temperature viscosity it's OK to call it a '15w40'".

WRT Mil Spec numbers: The two American numbers that you're most likely to
see in your owners manual are MIL-L-2104C and MIL-L-46152. Any modern 15W40
oil will easily exceed those requirements.

Trivially yours,

Alex

----- Original Message ----- From: "Bill Martin" <Martin_WJ@prodigy.net> > > After looking around some, it seems that the diesel oils commonly available > now (in Florida at least) are 15W/40 with API ratings of CH-4, CG-4, CF-4 > -- not 20W/40 and not single 30 weight. > Hi Bill, Not to worry, you'll be fine with 15w40 oil. 30 weight is perfectly OK as a second choice and 40 weight probably won't really hurt anything (especially in Florida heat). The main drawback to using heavier oils (like 40wt) is that, at start-up, it takes longer for the oil to get from the oil pan to where it's needed. In colder climates using a 40wt or even a 30wt can also cause sl-o-o-o-o-w cranking but that's probably not a big problem in Florida <G>. Now for a bit of oil trivia: For a long time there really was no such thing as 15w40. The SAE sets the standards for motor oil viscosity and they didn't actually have a standard for 15w40. What they had was a standard for 20w40 and a rule that said something like "If your 20w40 has a low enough low temperature viscosity it's OK to call it a '15w40'". WRT Mil Spec numbers: The two American numbers that you're most likely to see in your owners manual are MIL-L-2104C and MIL-L-46152. Any modern 15W40 oil will easily exceed those requirements. Trivially yours, Alex

F

fburrows@mail.com

Thu, Feb 28, 2002 3:44 PM

I find straight weight oils easily at the oil distributors but they are
disappearing from the shelves of retailers.

As a bit of trivia but not nautical information, I was in a Honda
dealership yesterday and they had a new chart that specified the particular
oil that was to be used in each vehicle. They listed a 0W-20 oil for one of
the 2002 models.

Frank Burrows

I find straight weight oils easily at the oil distributors but they are disappearing from the shelves of retailers. As a bit of trivia but not nautical information, I was in a Honda dealership yesterday and they had a new chart that specified the particular oil that was to be used in each vehicle. They listed a 0W-20 oil for one of the 2002 models. Frank Burrows

trawlers@lists.trawlering.com

TWL: Engine Oil