Best oil for a Mercruiser 3.0L?

[Condor1970]

I have a Mercruiser 3.0L, and was wondering what oil is preferred? You can't just use regular Mobil 1, can you?

I suppose the heavier duty Fram oil filters is out of the question too?

 

[Condor1970]

Don't worry, I did some research. Best to stick with Mercuiser full synthetic 20w-40, and the merc filters.

 

[jack black]

IMHO, you can run any HDEO either 15W40, 30, or 40. I don't see why you can't use compatible auto oil filters?

 

[achris]

It's a car engine, but is subject to sustained higher loads. As long as you stick to the suggested viscosity, you can use any oil you like. As for filters, again, as long as it meets spec, any brand you prefer....

 

[Starcraft5834]

Corn oil, Orville Redonbacher popcorn too.. you will have the best smelling exhaust on the lake :faint2:


my 3.0, it's older (87) calls for 10-30.. I bought 4 stroke Quicksilver 10-30... any oil u like....

 

[captainnate]

Mercruiser oil is flipping expensive. It doesn't seem justified.

 

[Condor1970]

Since it's an old engine from 1989, would it prudent to go with Mobil 1 10w-40 High Mileage oil?

Doesn't the high mileage oil help with leaks and has extra clenasers?

 

[jack black]

Since it's an old engine from 1989, would it prudent to go with Mobil 1 10w-40 High Mileage oil?

Doesn't the high mileage oil help with leaks and has extra clenasers?

The benefit of using Mobil 1 oil or similar oil in car engines is either:
1. Very high engine temps due to turbo or modifications.
2. Long oil change intervals (like up to 15,000 miles).

I don't think it applies to your boat, but I could be wrong.

 

[bspeth]

opcorn: this will get more than a few hits...

 

[H20Rat]

The benefit of using Mobil 1 oil or similar oil in car engines is either:
1. Very high engine temps due to turbo or modifications.
2. Long oil change intervals (like up to 15,000 miles).

I don't think it applies to your boat, but I could be wrong.

ironically mobil1 5w-30 is one of the worst oils that you can buy! It has been the death of many turbocharged subaru's... It shears down to roughly the same as water suprisingly quick. (note, other m1 oils are better, just avoid the 5-30)

 

[SDSeville]

Isn't there some risk of causing leaks going from dino oil to synthetic in an older engine?

 

[Condor1970]

Believe it or not, the studies show that any small leaks that occur, are usually temprorary, until they can swell back up when saturated with the new oil. This is something I am a little concerned with. However, if the leaks are initially not that bad, I will let it go until the system gets run in with the new oil, and see where it goes from there.

Just to let everyone know, I decided to try the Mobil 1 15w-50, as I have noted through internet searches, a lot of guys use it with success.

 

[bruceb58]

Isn't there some risk of causing leaks going from dino oil to synthetic in an older engine?

I think that may have been the case when Mobil 1 first came out because it was only available in a lower viscosity than other oils that were being used at the time.

 

[jack black]

Just to let everyone know, I decided to try the Mobil 1 15w-50, as I have noted through internet searches, a lot of guys use it with success.

Of course it will work. There will be no measurable benefits though. You still will have to change the oil after the season as it will be have a horrendous fuel dilution.
Have you studied UOA from the carburated 3.0?

 

[HT32BSX115]

End of season oil changes are more to set up for winter storage ..... I'm not sure why would there be fuel dilution....If you have fuel in the oil it's usually due to a failed fuel pump.

 

[airshot]

When you say "best" oil for your engine, in my opinion would be the oil that the manufacturer recommends as they have done all the studies to show what works best. However that does not mean that other oils won't work and probably be fine........but "best" would be manufacturers recommendation..

 

[friendly_jacek]

When you say "best" oil for your engine, in my opinion would be the oil that the manufacturer recommends as they have done all the studies to show what works best. However that does not mean that other oils won't work and probably be fine........but "best" would be manufacturers recommendation..

Normally I would agree with you, but there is that financial conflict of interest thing. This reminds me when mercruiser officially strongly advised AGAINST using synthetic oils in their engines and later they put one on the market and reversed their opinion. Things like that make you think.

 

[HT32BSX115]

Just about every oil has been tried in marine 4-stroke engines sucessfully including all the synthtics and non-syn multi-grades.

Oil related engine failures are more frequently related to either the oil not getting changed (ever), water in the oil, or no oil at all (leaked out or displaced by water)

brand,type and viscosity aren't really much of a factor.

 

[81 Checkmate]

ironically mobil1 5w-30 is one of the worst oils that you can buy! It has been the death of many turbocharged subaru's... It shears down to roughly the same as water suprisingly quick. (note, other m1 oils are better, just avoid the 5-30)

Smoke....My 2007 S/S Chevy Trailblazer... specifacly states to use Mobli 1 5w- 30 oil......Both on the oil fill cap and in the manual. Say's it will void the warranty if this oil is not used...... So do i go ahead a void the warranty...becouse you say it's one of the worst oils?
Do you have any back up info on this?


Just asking!

 

[bruceb58]

Smoke....My 2007 S/S Chevy Trailblazer... specifacly states to use Mobli 1 5w- 30 oil......Both on the oil fill cap and in the manual. Say's it will void the warranty if this oil is not used...... So do i go ahead a void the warranty...becouse you say it's one of the worst oils?
Do you have any back up info on this?


Just asking!

The Chevy Corvette comes from the factory with Mobil 1 5w-30. I would think if GM thought it was a problem, they wouldn't be using it.