Synthetic or mineral oil in low-hours motor

Froeman

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Sep 17, 2012
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Volvo 3.0 bought used with 41 hours. Mechanic says use mineral oil until the motor is a bit more broken in. Agree or disagree? Opinions please.
 

Grub54891

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Re: Synthetic or mineral oil in low-hours motor

Was this a volvo mechanic?
 

HT32BSX115

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Re: Synthetic or mineral oil in low-hours motor

Volvo 3.0 bought used with 41 hours. Mechanic says use mineral oil until the motor is a bit more broken in. Agree or disagree? Opinions please.

That's really an old wives tale. I have heard that for many years.

Just about ALL new cars nowadays come with a "factory-fill" of synthetic oil.

"Mineral oil" for many, means UN-compounded oil or "NON-detergent" oil (API SA)

DO NOT USE NON-DETERGENT API SA oil in ANYTHING! except maybe your lawn mower!

The only thing I would use it in is my waste-oil furnace!



Regards,


Rick

As an aside, if the piston rings (which is what we're talking about) in a marine engine are not broken-in by 40 hours, they're not going to break in.
 

doyall

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Re: Synthetic or mineral oil in low-hours motor

Perhaps the mechanic means 'conventional' as opposed to 'synthetic' oil, although these days the line between the two is more blurred than bright.

A good quality brand conventional oil that meets the 'manufacturer's' specs will be more than sufficient for most un-modified engines during wear-in and beyond.
 

muc

"Retired" Association of Marine Technicians...
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Re: Synthetic or mineral oil in low-hours motor

I’m guessing that you did talk to a Volvo mechanic. Because he is right if the engine hasn’t had its first oil change.
Volvo sells a product they call mineral oil for use in new engines before they have had the first oil change to the recommended synthetic oil.
As a Volvo dealer this is what we sell customers to use if they have to add oil during break-in. It is also the oil Volvo has us use for the first fill when we replace an engine under warranty.
But hey, this is an oil question so you will get as many different answers as you want. So feel free to listen to car, plane, train or motorcycle people.
 

HT32BSX115

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Re: Synthetic or mineral oil in low-hours motor

Volvo sells a product they call mineral oil for use in new engines
Not a thing wrong with selling a product to improve the "bottom line"!!

Doesn't matter if it's used in an engine that goes in MILLIONS of cars that break-in quite normally without it.

So, if you can get people to buy it, you've done your job!

The people that sold Slick-50 to millions of unsuspecting suckers (I mean people) thought they did too. Until the Federal Trade Commission sued them (and won)

Your mileage of course, may vary.......
 

muc

"Retired" Association of Marine Technicians...
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Re: Synthetic or mineral oil in low-hours motor

73 de Rick
Not too sure about your “bottom line” comment. We make less money off of the mineral oil (it sells for less than the synthetic oil) and we sell very little of it because very few boats in our area need any oil added between oil changes. So selling it actually hurts our “bottom line” but we feel its in the best interest of our customers to do so.

I agree with you on the “doesn’t matter” car thing. Boat engines have a different duty cycle than car engines and while they may start out as a car engine (before they are marinised) they do live in a different environment.

As for doing my job. I try to treat our customers the same way I treat my brother and his boat (except I don’t charge my brother labor) that is, I try to give them advice based on how and where they use their boat (tempered with my 30 years of experience as a marine mechanic) so they can get maximum enjoyment from their boat. I honestly believe that trying to save a few bucks by buying cheap oil and aftermarket parts ends up costing more in the long run.

I wasn’t aware of any engine manufacturers that recommended “slick 50” I think there is a huge difference between recommendations from Volvo vs. late night infomercials.
 

aerobat

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Re: Synthetic or mineral oil in low-hours motor

the idea of mineral oil on a brand new engine is it has lower shear stability than modern synthetic oils and so helps to break in the rings against the cylinder wall - so the statement of muc is basicly correct.

BUT at 41 hours that job is already done, so use any oil you want.

the crucial part of break in are the first 1-2 hours in its life , and to prevent people f**ck this completely up many manufacturers run the really new engine on a teststand for some minutes where it gets some hard bursts of throttle - so the opposite most people would believe is correct for break in.

that is done to build up cylinder pressures and pushing the piston rings hard against the cylinder wall to achieve an initial sealing.

cheers
 

HT32BSX115

Supreme Mariner
Joined
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Messages
10,083
Re: Synthetic or mineral oil in low-hours motor

the idea of mineral oil on a brand new engine is it has lower shear stability than modern synthetic oils and so helps to break in the rings against the cylinder wall - so the statement of muc is basicly correct.

BUT at 41 hours that job is already done, so use any oil you want.

the crucial part of break in are the first 1-2 hours in its life , and to prevent people f**ck this completely up many manufacturers run the really new engine on a teststand for some minutes where it gets some hard bursts of throttle - so the opposite most people would believe is correct for break in.

that is done to build up cylinder pressures and pushing the piston rings hard against the cylinder wall to achieve an initial sealing.

cheers

Many car manufacturers "factory fill" their engines with synthetic right at the factory. Maybe they "break them in" before the dealers even get them.

When I used to work at an aircraft repair facility, we would break in the rings by flying the airplane around the local area at full throttle//max RPM for about 15-20 min.......

The rings would break in almost immediately. The owner insisted on using non-compunded (non detergent) oil. Later we used detergent (regular) oil and found no difference. You could see the break-in point happen because the cyl-head temp would quickly and obviously drop.

Can't do that with liquid cooled engine though. But we broke-in every other engine we rebuilt (including boat engines) the same way. max power/max RPM for 15-20 min or so. They never burned oil after that. It didn't seem to matter what type of oil we used.

The rings don't care how they're lubricated. like you said. It's all about cylinder pressures.
 

Fleetwin

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1,141
Re: Synthetic or mineral oil in low-hours motor

If Volvo is paying the potential warranty bills, they can demand whatever they want.

Do what the manufacturer (whoever) says. They have their reasons based on research and experience. It isn't because they want to sell oil. A few thousand quarts of oil doesn't cover the cost of a couple blown engines. At least follow their advice until you are out of warranty.

I never use anything but OEM for anything, unless OEM is impossible to find.
 
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