Would GC 0W30 be a good choice for VolvoPenta sterndrive motors (marinzed small block chevy)?
GC - Marine Use?
- Thread starter DockHoliday
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GC is almost a 40 Weight anyways
Last time I checked, Volvo actually recommended a straight 30W synthetic. I think that's why their motors put out 5 hp more than the same engine in a Mercruiser.
I know that if you tell the average boater that you have 0Wxx oil in your boat that you will be laughed off the lake. However, I think that may be "old school" thinking. If GC is as good as everyone claims, it should hold up just fine for the 50 hours of boat use each season. Also, if marine engines are so hard on oil, wouldn't a synthetic oil hold up better? Keep in mind that the engines haven't changed that much in the last 25 years (at least the GM V8s), while motor oils have improved dramatically. Is it time to rethink motor oil selection for marine use?
My motivation is simply have a single oil that I can use in everything.
My motivation is simply have a single oil that I can use in everything.
Marine engines need an oil that can handle severe fuel dilution and then be run at 3-4500 rpm all day then sit for 2 weeks and cling to the engine to prevent corrosion. Automotive oils simply do not have the necessary addtive packages to handle the fuel dilution. Nobody ever wears out marine oil in 50 hours....but they do dilute it out. I have had over 10 UOA's on this with marine oil at 80 hours and the oil was still good but the fuel dilution was always what forced you to change it. If GC can handle a fuel dilution up to 17% then use it.....but I wouldn't. A 7.4L marine engine costs over $10,000.
KBFXDLI,
I'm just curious. Why do marine engines have such high fuel dilution?
a_g
I'm just curious. Why do marine engines have such high fuel dilution?
a_g
As much as I like this oil, I'd be very reluctant to use it in a marine environment. And certainly not in a marine diesel.
With all the additional adverse conditions that these engines operate under, they seem to hold up better on straight and multivis weights in the higher 40s and 50s. Heavier HDEOs are the preferred genre in my book. I don't know anyone who runs, or who would be willing to chance, a 0W oil. These engines are too expensive to play guinea pig with.
One PCMO that seemed to hold up OK was the older pre Tri-Synthetic formula M1 15w-50. But I'm not sure I'd use the newer PCMO M1 formulas.
With all the additional adverse conditions that these engines operate under, they seem to hold up better on straight and multivis weights in the higher 40s and 50s. Heavier HDEOs are the preferred genre in my book. I don't know anyone who runs, or who would be willing to chance, a 0W oil. These engines are too expensive to play guinea pig with.
One PCMO that seemed to hold up OK was the older pre Tri-Synthetic formula M1 15w-50. But I'm not sure I'd use the newer PCMO M1 formulas.
Always an interesting discussion. I actually came to the conclusion a few years back that dino oil, with the help of LC, is a very simple choice. To be honest, any oil I use in the boat would have to come in 1 gallon jugs (needed to store the old oil).
Thanks for entertaining the idea.
Thanks for entertaining the idea.
I've had excellent results (comparable to the Amsoil 15w-40/AME), with their CI-4+/SL rated, Series 3000 5w-30 in Mercruiser inboards. These motors come with the 25w-40 Mercruiser oil, which is basically a straight 40wt.
An SAE 0w-30 synthetic would probably be okay for very cold weather marine use where you never reach normal oil temps. However I'd expect to see increased bearing and ring/cylinder wear in warm weather, along with increased oil consumption.
The other issue with some types of marine use is excessive fuel dilution. This is also the one of the main reasons why 40wt and 50wt oil are typically speced for these applications.
An SAE 0w-30 synthetic would probably be okay for very cold weather marine use where you never reach normal oil temps. However I'd expect to see increased bearing and ring/cylinder wear in warm weather, along with increased oil consumption.
The other issue with some types of marine use is excessive fuel dilution. This is also the one of the main reasons why 40wt and 50wt oil are typically speced for these applications.
MArine engine design with forged pistons usually allows lots of blow-by at start up. Fuel gets in the oil and stays in. Plus most boaters are short tripers and run their engines 50/year or less which equates to 2500 miles of stop and go. Lots of times guys will take their boat out for a 2-3 hour run and come back and think they used a quart of oil when in reality they burned off mostly fuel. You really don't need a 25w40 until you dump a pint of gasoline in it and run it at 4000 rpm continuously.
Other potentially complicating factors include:
1) Over cooling (USCG mandates a 160 degree thermostat).
2) Extended period in now wake zones (for some boaters)
3) Heavy loads at WOT (hole shot).
Do EFI engines incur less fuel dilution?
1) Over cooling (USCG mandates a 160 degree thermostat).
2) Extended period in now wake zones (for some boaters)
3) Heavy loads at WOT (hole shot).
Do EFI engines incur less fuel dilution?
KBFXDLI,
that makes sense to me. thanks.
a_g
that makes sense to me. thanks.
a_g
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