Indmar and inconsistent oil viscosity recommendations...

[Nitrousbird]

Indmar has shown to be inconsistent with their viscosity recommendations on motors.

Up through 2005, it is 15W40 for everything.  Of an interesting, unrelated side note, they list a Malibu LC2 engine in the 2003 - 2005 manual and 2006 manual.  They use GM motor codes for a lot of their engines - that just so happens to be the one for the intercooled turbo V6 used in the Buick T Type, Grand National and 20th Anv. Turbo Trans Am...motors that never made it into a Malibu.  Anyway...

2006, the chart shows 15W40 for all engines, but the description calls out the 8.1L as running straight 40 weight.  2007 manual does the same thing.  For the 2008 - 2009 manual, the chart now reflects 40 weight for the big block.  The LS7 is introduced and has 5W30 but yet the LS2 and LY6, also GEN-IV small blocks, are still 15W40.

2010 - 2011 gets interesting.  The LS2 gets moved to the 5W30 chart, where the LS3 is now added in as well, yet the LY6 and added L96 are still at 15W40, even though they are a similar cross between an LS2 and LS3 (same cylinder heads as the L92/LS3, similar block design as the LS3 with a much lower compression ratio and iron block).  The LSA motor is totally omitted from the chart, but there is a text mention that all LS motors get 5W30.

2012-2014 really cleans up the chart, likely due to Mastercraft dropping Indmar and Indmar having a much leaner lineup.  LS3 and LSA are 5W30, while the L96 and old GEN-I small block being 15W40.

2016 moves to the Ford stuff and they FINALLY revamped their owners manual.  No more chart, but everything gets 5W30 except the supercharged motors, which get 15W50!  The '17 and '18 manual carry over as the same.

I'd love to know where Indmar comes up with their choice in oil viscosity, which doesn't change regardless of conventional and synthetic.  I have an older LS series motor (LS1) and have ran 15W40 as recommended, but that's only what they recommend in the marine motors as the auto version is 5W30 like every other GEN-III+ motor GM has released.  Remember, later on Indmar starts recommending 5W30 as well on LS2/LS3/LSA.  I'm considering moving to a 5W30 as well for that, which would allow me to share oil jugs with the L92 in my truck.  Thoughts?

All manuals can be found here, but watch the link, as they have a couple manuals linked to the wrong year.  https://www.indmar.com/operator-manuals/wake-series/

 

  

[granddaddy55]

Boat must put away for winter?

i feel bad for you guys!

[Woodski]

@Nitrousbird:  Since you asked, I have run my engine on 5W-30 for years with no issues, just recently went up in viscosity as oil pressure at idle when hot was a bit low, it does have over 1k hours on it.  Standard SBC but significantly massaged by yours truly with aluminum heads fast burn heads, intake exhaust manifolds, ZZ4 cam so its putting out ~400 hp.  All the GM engines are validated on 5W-30 oils and probably even lower viz these days, been quite a while since I have been on the dyno.  You should see an endurance test on the dyno, the exhaust manifolds glow bright red at WOT and loaded.  I would not have a concern running 5W-30, but then again I have been around engines for decades and have no issues doing all my own work.  I have also done a lot of experimenting on race cars, etc. so I probably take a little riskier approach to many engine related items.

[oldjeep]

I just stick in whatever the manual says - in everything I own.  Not concerned about why they might be inconsistent.  If it says regular 15W40 then that is what it gets, if it says it needs synthetic then that is what it gets.  I've never been a believer in sticking synthetics into anything that the manual isn't saying needs them.  Never seen an oil related failure in anything (other than an engine that wasn't real happy about running upside down with no oil pressure)

[Nitrousbird]

1 hour ago, granddaddy55 said:

Boat must put away for winter?

i feel bad for you guys!

Nope, but am gathering my winterizing stuff that I will be doing in a month or so. Though this weekend is looking like crap but last weekend was like the middle of summer other than the water being colder.

[Nitrousbird]

47 minutes ago, oldjeep said:

I just stick in whatever the manual says - in everything I own.  Not concerned about why they might be inconsistent.  If it says regular 15W40 then that is what it gets, if it says it needs synthetic then that is what it gets.  I've never been a believer in sticking synthetics into anything that the manual isn't saying needs them.  Never seen an oil related failure in anything (other than an engine that wasn't real happy about running upside down with no oil pressure)

At $22.xx for a 5 quart jug of Mobil One synthetic, why not?  I even run it in my lawn mower.

[oldjeep]

7 minutes ago, Nitrousbird said:

At $22.xx for a 5 quart jug of Mobil One synthetic, why not?  I even run it in my lawn mower.

Well, for a few reasons -

1) why spend more money than needed?

2) Pretty sure there is no such thing as 15W40 Mobile 1 and 15W40 is what Indmar said to put in my motor

In terms of the cars, I don't change the oil myself - not worth the hassle.  My $35 7 quart conventional oil change at the dealer more than doubles in cost with synthetic and after 175K with conventional bulk oil on the last Hemi I really see no reason to spend the money.

Edited October 10, 2018 by oldjeep

[SkiPablo]

3 hours ago, Nitrousbird said:

I'd love to know where Indmar comes up with their choice in oil viscosity, which doesn't change regardless of conventional and synthetic.  I have an older LS series motor (LS1) and have ran 15W40 as recommended, but that's only what they recommend in the marine motors as the auto version is 5W30 like every other GEN-III+ motor GM has released.  Remember, later on Indmar starts recommending 5W30 as well on LS2/LS3/LSA.  I'm considering moving to a 5W30 as well for that, which would allow me to share oil jugs with the L92 in my truck.  Thoughts?

All manuals can be found here, but watch the link, as they have a couple manuals linked to the wrong year.  https://www.indmar.com/operator-manuals/wake-series/

 

  

i also have the LS1 - Indmar told me I could run 5w30 as long as it was synthetic as well but I've chosen to run 15w40 conventional.    The previous owner ran M1 15w50 and I think that stuff was a tad too thick for this engine. 

I spent way too much time on this last year reading - the conclusion I came too is the 15w40 helps with the fuel dilution as you get closer to 50 hours on the oil.  

one inconsistency I saw with the manual is they call or 5.5 quarts of oil for all the 5.7 engines - but my LS1 actually takes 6 quarts

 

[Nitrousbird]

8 hours ago, oldjeep said:

Well, for a few reasons -

1) why spend more money than needed?

2) Pretty sure there is no such thing as 15W40 Mobile 1 and 15W40 is what Indmar said to put in my motor

In terms of the cars, I don't change the oil myself - not worth the hassle.  My $35 7 quart conventional oil change at the dealer more than doubles in cost with synthetic and after 175K with conventional bulk oil on the last Hemi I really see no reason to spend the money.

1 - cost is about the same between conventional.

2 - correct and the whole point of the thread that Indmar is inconsistent with both their recommendations through the years and following what GM and Ford do on the automotive versions of these motors. 

As for dealer oil changes, BMW and Audi both want around $90 to do what I can do in my garage for under $40 (our cars require synthetic).  Time is saved as the time driving to the dealer, waiting and driving home is longer than doing it myself at the comfort of my own schedule...and I know I'm doing a better job.  

I'm sure I could find a break even deal for my truck with conventional...but I still save time and get to run synthetic.  It's also a bad piston slapper when cold so any additional protection I can give it is a good thing. 

 

[oldjeep]

13 minutes ago, Nitrousbird said:

1 - cost is about the same between conventional.

2 - correct and the whole point of the thread that Indmar is inconsistent with both their recommendations through the years and following what GM and Ford do on the automotive versions of these motors. 

As for dealer oil changes, BMW and Audi both want around $90 to do what I can do in my garage for under $40 (our cars require synthetic).  Time is saved as the time driving to the dealer, waiting and driving home is longer than doing it myself at the comfort of my own schedule...and I know I'm doing a better job.  

I'm sure I could find a break even deal for my truck with conventional...but I still save time and get to run synthetic.  It's also a bad piston slapper when cold so any additional protection I can give it is a good thing. 

 

For the boat the 15W40 Delo costs me $13 a gallon

For the truck - Doesn't save me any time or money to DIY.  Ram dealer is 5 miles away and has an express oil change line.  Drive in, read my email in the lobby and drink their coffee for a while and drive out.  No oil to dispose of, no mess and I only walk out $35 lighter.

[granddaddy55]

Wife’s new GT is 10 quarts of full synthetic

one dealer wanted $90 plus shop supplies plus tax, another that wanted my business did it for $54 inc tax including tire rotation and other fluid checks , DONE, did it in 30 minutes arriving late (8:am) on a saturday morning  when everybody goes

they did my eco with 6 semi synthetic qts and tire rotation fir $42-45 inc tax,   the will charge me same prices for both and 4th oil change for no charge including rotation for the whole acct(3 changes total for both  cars, 4th one free)

Edited October 11, 2018 by granddaddy55

[MadMan]

Yep, many dealers have a very competitive price on their oil changes.  The scheme is to then identify other, much more profitable service items.  They key is not to fall for it, just get the oil changed.