Lake St. Clair Fishing Forum banner
1 - 20 of 25 Posts

·
Registered
Joined
·
22,943 Posts
Discussion Starter · #1 ·
As I crack 750 miles this season, I'm thinkin' oil change. Just wondering what some of your opinions are with synthetic oils. Is it worth the extra cost? Is it adequate or better to just change conventional oil more often, or is it reasonable to expect longer service from synthetic oil? When changing to synthetic, how does it intermingle with remnant conventional oil? Should the first run of synthetic be changed early to be certain of 100% synthetic?

Thanks!


(This should probably be in the Cruising Forum, but I figured it might get more air time here. )
 

·
Registered
Joined
·
9,917 Posts
I always used synthetic (amsoil) in my Four Winns. And for the outboard in the dink, I use amsoil's outboard oil. I just figure with the high constant RPM's, conditions, and abuse those motors take, synthetic is the way to go.
 

·
Registered
Joined
·
1,146 Posts
Well, I have a different thought on this. Synthetic oils are terrific in our cars. Their big selling and performance points are their ability to go the distance and increase the duration between oil changes without losing the ability to do their job.

In our boats however, I don't think that we realize those benefits. We change oil every 100 hours, not because the dino oil is bad, or "worn out", but because the hit and miss use in our boats tends to pollute the oil in the crankcase.

We routinely see our marine engines go 1200 - 1500 - 2000 hours using old school petroleum...... Do you really think you will see a huge increase in lifespan from going to a syn oil? It's yet to be proven, and I think money not very well spent.....

Of course, if it makes you feel better having it in there, by all means, go for it!! You have to be confident in your set up!! But I recently spent a good bit of time on the phone with a chemical engineer at Shell having this exact discussion!! In the end I ended up changing to Shell Rotella T 15W-40. Obviously a Shell product, but the guy also made point that Chevron Delo 400 was a premium oil that would serve our marine engine well!! (not even a Shell product!!)

Sorry so long winded, but that's my story and I'm sticking to it!!
 

·
Registered
Joined
·
1,005 Posts
QUOTE(garry454 @ Jun 29 2009, 08:37 AM) <{POST_SNAPBACK}>Well, I have a different thought on this. Synthetic oils are terrific in our cars. Their big selling and performance points are their ability to go the distance and increase the duration between oil changes without losing the ability to do their job.

In our boats however, I don't think that we realize those benefits. We change oil every 100 hours, not because the dino oil is bad, or "worn out", but because the hit and miss use in our boats tends to pollute the oil in the crankcase.

We routinely see our marine engines go 1200 - 1500 - 2000 hours using old school petroleum...... Do you really think you will see a huge increase in lifespan from going to a syn oil? It's yet to be proven, and I think money not very well spent.....

Of course, if it makes you feel better having it in there, by all means, go for it!! You have to be confident in your set up!! But I recently spent a good bit of time on the phone with a chemical engineer at Shell having this exact discussion!! In the end I ended up changing to Shell Rotella T 15W-40. Obviously a Shell product, but the guy also made point that Chevron Delo 400 was a premium oil that would serve our marine engine well!! (not even a Shell product!!)

Sorry so long winded, but that's my story and I'm sticking to it!!


I'm of the same opinion; except the 15W40. If you don't boat in cold weather I don't see the need for multi viscosity oil. I run straight 40WT dino oil.
 

·
Registered
Joined
·
10,183 Posts
Well, I'll admit that I am a synthetic 'bigot'. I run it in everything, for different reasons. The only time I run conventional anymore is to "flush" between changes when in a high milage motor. In my truck and car, at 150,000 I go get a cheap oil change then within a couple hundred change it again back to synthetic.

With a high quality oil and under most conditions, you don't really NEED synthetic. I do it because there are times when you are pushing the conditions.... like going boating in NOVEMBER (I've had to scrape ice off the windscreen). I understand it also does not build acids like conventional oils do so it's better for long-term storage.

In generators, compressors, snowblowers, lawn tractors, etc, it helps with startup-up under cold conditions...and it doesn't really have to be that 'cold' to be a cold start condition, but you will REALLY appreciate it if you have to pull-start that generator in the winter. It'll prevent a compressor from blowing circuit breakers on start-up too.

Think about your marine engine, as opposed to a car. You are VERY frequently pushing the output and RPM limit on the engine for extended durations. Then it's sitting in 'non-ideal' conditions full of moisture. It's VERY expensive and time-consuming if there is a failure, so if a little bit of extra protection helps some "marginal" part from failing, it pays off in a big way. The extra cost of a few synthetic oil changes is fractional compared to the cost of gas that goes to support the boat.

I also use synthetic in two-strokes, because it does burn cleaner and will minimize the exhaust valves from sticking (which probably means the pistons and other internal parts are staying cleaner too!)

I use Mobil1 exclusively, but AMSOIL and REDLINE and others are great oils too
 

·
Registered
Joined
·
1,461 Posts
QUOTE(pquest29 @ Jun 29 2009, 08:58 AM) <{POST_SNAPBACK}>If you don't boat in cold weather I don't see the need for multi viscosity oil. I run straight 40WT dino oil.

I agree... multiweight oil is for engines that don't get "warm up" time.
...How many of you here start the motor in your boat and zoom off like you would in your car?
...When's the last time you started your boat in 12 degree weather? (or even 30 degrees)
Synthetic oil in your boat, IMO, is a waste of cash. Multigrades (dino oil), unless called for, will thin out or break down under marine load conditions if you try to get extra hours out of 'em. My 35 year old 318's (original) have never seen anything but dino oil and never less than straight 30W SAE (now running 40W).
 

·
Registered
Joined
·
1,146 Posts
QUOTE(pquest29 @ Jun 29 2009, 08:58 AM) <{POST_SNAPBACK}>I'm of the same opinion; except the 15W40. If you don't boat in cold weather I don't see the need for multi viscosity oil. I run straight 40WT dino oil.

I agree that the multi viscosity is not really necessary, but I went with the multi because the manual calls for it as the preferred weight. The straight weight falls way down on the list, as a last resort almost........
 

·
Registered
Joined
·
1,461 Posts
....Are there indeed any manufacturers that "spell out" synthetic as a warranty requirement??
I don't think any of the auto manufacturers do, and I'm pretty positive NONE of the marine engine companies do (in fact, I think there've been issues with voiding warranties due to type of oil found in the crankcase).
 

·
Registered
Joined
·
1,043 Posts
The mechanic I used to deal with back in the day told me not to run full synthetic (I did not bother to get into why). He recommended Mercury semi synthetic so thats what I run.

In my cars I run Mobil 1 full synthetic.
In the boat I run Mercury Semi syn (mercruiser engine)
In my 2 strokes I run Amsoil full synthetic.

The one thing I have heard is that if you have an engine with a lot of hours/miles running on regular oil many of the seals will have deposits on them that actually help keep them from leaking. And that the extra detergents in synthetics will break these deposits down and you could end up with leaky seals. Don't know if there is any truth to it, just something I came across in my research.
 

·
Registered
Joined
·
1,470 Posts
QUOTE(Capn Ken @ Jun 29 2009, 11:46 AM) <{POST_SNAPBACK}>....Are there indeed any manufacturers that "spell out" synthetic as a warranty requirement??
I don't think any of the auto manufacturers do, and I'm pretty positive NONE of the marine engine companies do (in fact, I think there've been issues with voiding warranties due to type of oil found in the crankcase).

As long as the oil meets or exceeds the specification they call for, they cannot void any coverage.
Synthetic oils reduce wear, heat & extend life of your engine, and last much longer than conventional motor oils, extending your change periods (hours).

Away point, depending on what type you decide, I stock most viscosities of Amsoil, along with extended life filters. Call me if you have questions.
586-777-4444-rich

Also, in marine applications, its always best to replace the oil & filter in the fall. Keeping old oil in the block over the winter months is not good. The contaminates found in old engine oil eat away at components.
 

·
Registered
Joined
·
56 Posts
I am a Tech the diffrence between the to oils is, flow in colder temps, break down of the oil what I mean is SLUDGE, it is from heat, boat motors generate a lot of heat at higher RPM that breaks down oil which causes premature engine wear. I recommend synthetic oil for any engine it can not harm anything. Mobil 1 is my preference I use it in everthing.



Also a lot of manufactures recommend it now for exp

Chevy

Dodge

Ford 5w20 syn
 

·
Registered
Joined
·
1,228 Posts
My experience is to simply change your oil and filter often. Depending on the engine, 10, 25, no more than 40 hours.
Everybody has an opinion on oil, just like what boat is best. There is alot of research on the net.
I had an interesting experience in a pair of Hawk 600 HP's. The owner wanted 100 percent syn oil. Picked up lifter noise in both engines. Went back to regular oil and lost the lifter noise. Same Weight oil. Other than that incident, never a problem one type or the other.
I change my oil every 20 hours, and on the hi-perf engines, every time I go out.
 

·
Registered
Joined
·
22,943 Posts
Discussion Starter · #16 ·
I appreciate all the feedback!
 

·
Registered
Joined
·
732 Posts
QUOTE(KMC @ Jun 29 2009, 09:16 AM) <{POST_SNAPBACK}>Well, I'll admit that I am a synthetic 'bigot'. I run it in everything, for different reasons. The only time I run conventional anymore is to "flush" between changes when in a high milage motor. In my truck and car, at 150,000 I go get a cheap oil change then within a couple hundred change it again back to synthetic.

With a high quality oil and under most conditions, you don't really NEED synthetic. I do it because there are times when you are pushing the conditions.... like going boating in NOVEMBER (I've had to scrape ice off the windscreen). I understand it also does not build acids like conventional oils do so it's better for long-term storage.

In generators, compressors, snowblowers, lawn tractors, etc, it helps with startup-up under cold conditions...and it doesn't really have to be that 'cold' to be a cold start condition, but you will REALLY appreciate it if you have to pull-start that generator in the winter. It'll prevent a compressor from blowing circuit breakers on start-up too.

Think about your marine engine, as opposed to a car. You are VERY frequently pushing the output and RPM limit on the engine for extended durations. Then it's sitting in 'non-ideal' conditions full of moisture. It's VERY expensive and time-consuming if there is a failure, so if a little bit of extra protection helps some "marginal" part from failing, it pays off in a big way. The extra cost of a few synthetic oil changes is fractional compared to the cost of gas that goes to support the boat.

I also use synthetic in two-strokes, because it does burn cleaner and will minimize the exhaust valves from sticking (which probably means the pistons and other internal parts are staying cleaner too!)

I use Mobil1 exclusively, but AMSOIL and REDLINE and others are great oils too

Exhaust valves in a 2-stroke motor.......really?????
 

·
Registered
Joined
·
202 Posts
Amsoil in everything. Boat motors were over 10k each so a little extra for synthetic oil is no biggie. I only noticed one person mention filters. There is a huge difference in oil filters. I always use amsoil filters. Filter media and a bypass valve is way better than a cardboard (fram) filter. In your cars and truck dont forget to keep the air filter clean or replaced. A motor uses a heck of a lot more air to run than it does gasoline or diesel.
 
1 - 20 of 25 Posts
Top