Oil.. Mineral or Semi Synthetic

[Biggles]

A chat down t pub the other day turned to oil, surprisingly and probably for the first time too toilets didn't make an appearance.

 

My engine is specified with 15w/40 semi synthetic, but the question reared at the pub was that as my or indeed many marinised engines are running at set speeds for long periods of time weather mineral oil was better than semi or fully synthetic oil. This was especially debated when the engine is running without load for charging or hot water.

[bottle]

Go with the engine specifications.

[mrsmelly]

A chat down t pub the other day turned to oil, surprisingly and probably for the first time too toilets didn't make an appearance.

 

My engine is specified with 15w/40 semi synthetic, but the question reared at the pub was that as my or indeed many marinised engines are running at set speeds for long periods of time weather mineral oil was better than semi or fully synthetic oil. This was especially debated when the engine is running without load for charging or hot water.

 

Hi

 

Synthetic oil, is mineral oil. The bp bods etc make it from petroleum based products or crude oil so it is mainly mineral oil.

 

Tim

Edited July 8, 2012 by mrsmelly

[George94]

Hi

 

Synthetic oil, is mineral oil. The bp bods etc make it from petroleum based products or crude oil so it is mainly mineral oil.

 

Tim

 

Not necessarily. It is possible to make synthetic oil entirely from vegetable or animal products. But the important thing is whether there is anything in synthetic oil which makes it unsuitable for engines that were specified to take mineral oil. Synthetic oils can attack some plastics.

 

The big advantage of synthetic oils is that they can withstand higher temperatures than mineral oils. On the cut, this is seldom going to concern us, so going for cheaper mineral oil is unlikely to be much of a disadvantage.

 

If you have a really old engine, the important thing is to go for a non-detergent oil, because older engines were not fitted with modern oil filters. They rely on debris being deposited in the sump, rather than being filtered out. In the absence of a filter, a modern detergent oil will continue to carry the debris round the engine, which isn't a recipe for long engine life.

[Biggles]

The debate was bore glaring and that semi synthetic was more given to making this happen.

 

True?

[Timleech]

Not necessarily. It is possible to make synthetic oil entirely from vegetable or animal products. But the important thing is whether there is anything in synthetic oil which makes it unsuitable for engines that were specified to take mineral oil. Synthetic oils can attack some plastics.

 

The big advantage of synthetic oils is that they can withstand higher temperatures than mineral oils. On the cut, this is seldom going to concern us, so going for cheaper mineral oil is unlikely to be much of a disadvantage.

If you have a really old engine, the important thing is to go for a non-detergent oil, because older engines were not fitted with modern oil filters. They rely on debris being deposited in the sump, rather than being filtered out. In the absence of a filter, a modern detergent oil will continue to carry the debris round the engine, which isn't a recipe for long engine life.

 

I suppose it all depends...

 

The small aircooled Listers, for instance, had only a coarse sump strainer as standard but I wouldn't dream of putting a non-detergent oil into one. The normal recommendation for older diesels, of 'Supplement 1' specification, an obsolete US military spec which is I understand similar to the current API-CC spec, applies to those. I agree that HIGH detergency oils should be avoided.

Have you seem the inside of a diesel which has been run with non-detergent oil?

 

It used to be said that oil filtration was much less important on a diesel than a petrol engine.

 

Tim

[Bobbybass]

I am interested in answers..as I am pondering oils both on boat and car at present.

 

My Beta 43 (8000 hours) has been run all its life on Halfords own diesel engine 'enhanced mineral' oil. It seems to be fine..no smoke..doesn't use any oil between 220 hour changes.

The Halfords stuff is now about £19 / 5 litres...so I am just about to try Wilkinsons own diesel engine 'mineral based' oil which is only £12/ 5 litres..

Do you think that is a risk..considering I religiously do the changes at less than the 250 hours recommended by Beta..?

 

My ancient car (Peugeot 306 diesel non-turbo..I never spend more than £400 on a car these days !!)

The Halfords 'list' says to use 10/40 semi-synthetic..(£23/ 5 litres) which I have done. The changes should be at 6000 (as per book) but I do them at about 4000.

Another 'list' says that I can use 'part synthetic'..and Wilkinsons do this at £14.50/ 5 litres.

I'm not sure what the difference is between semi-synthetic or part- synthetic ?

I guess my Peggout is quite old (1997) and I only drive at no more than 50 mph...so should it be OK..?

 

Thanks for the expertise..

[bowten]

I am sure in the Isuzu manual it says use mineral oil only,when I checked the grading it was very low so used the cheapest mineral oil available.The Isuzu is a modern Jap engine so I presume in the environs of a canal boat I believe a cheap mineral oil would be suitable for most engines...........but before long someone will be along to prove me wrong.

Edited July 8, 2012 by bowten

[ditchcrawler]

A chat down t pub the other day turned to oil, surprisingly and probably for the first time too toilets didn't make an appearance.

 

My engine is specified with 15w/40 semi synthetic, but the question reared at the pub was that as my or indeed many marinised engines are running at set speeds for long periods of time weather mineral oil was better than semi or fully synthetic oil. This was especially debated when the engine is running without load for charging or hot water.

I think if it was me and that is what is specified by the engine manufacturer that is what I would use.

[Biggles]

It's not the cost issue although saving a few bob is always worthwhile. Halfords oils they told me were made by Comma.

 

I think during warranty will stick to the recommended.

 

So why can a car go for 10000 miles of harder use than a boat engines but we have to do ours at 250 hours or so?

[Timleech]

A chat down t pub the other day turned to oil, surprisingly and probably for the first time too toilets didn't make an appearance.

 

My engine is specified with 15w/40 semi synthetic, but the question reared at the pub was that as my or indeed many marinised engines are running at set speeds for long periods of time weather mineral oil was better than semi or fully synthetic oil. This was especially debated when the engine is running without load for charging or hot water.

 

Is your engine supplied by a reputable mariniser, and is that their recommendation? Also is it an engine that is commonly supplied for Inland waterway (usually low duty) use? Or is it the recommendation of the makers of the core engine?

 

Tim

[RLWP]

 

So why can a car go for 10000 miles of harder use than a boat engines but we have to do ours at 250 hours or so?

 

10,000 miles at 60 MPH is 166 hours

 

Richard

[bowten]

10,000 miles at 60 MPH is 166 hours

 

Richard

Damn your good!

[RLWP]

Damn your good!

 

I worked it out ages ago when I also wondered why we had to do oil changes at such short intervals

 

Richard

[David Mack]

10,000 miles at 60 MPH is 166 hours

 

Richard

 

Do you average 60mph over 10,000 miles?

[RLWP]

Do you average 60mph over 10,000 miles?

 

Well, if you prefer, 10,000 miles in 250 hours is 40MPH

 

Richard

 

I worked it out for you to avoid you travelling faster than the speed of light

Edited July 8, 2012 by RLWP

[mrsmelly]

The debate was bore glaring and that semi synthetic was more given to making this happen.

 

True?

 

Hi

 

Right well lets just say with regard to oil that if you change it as specified your engine will outlive you probably. As a for instance the engines in one of the boats I drive at work where both fitted as new units in 1997 there is a daily extensive record of all works to the boat since that date. We check the engines every time before we start them before each cruise. Neither engine has had any major work and neither has even had the head removed and the engines burn very small amounts of oil. We use bog standard 15/40 mineral oil and change the filter and oil every 200 hours. Each engine is now approaching 30,000 hours and still start instantly and run sweet as a nut. Nuff said.

 

Tim

[dor]

Vetus say 100 hours between oil changes. Being as it is a basic Mitsubishi underneath, this smacks of Vetus' aim to sell more oil and filters.

 

I can't see our under-stressed engines suffering if the oil is changed every 300 or so hours.

[bizzard]

I fitted exchange injectors to a 4cyl Kubota a couple of weeks ago,at 54,000 or so hours. Apart from normal servicing this and a new fuel lift pump last year is all the engines ever required. Most of its use is 6 hours stationary daily battery battery charging out of gear during the winter and cruising all summer. The engine is still in excellent. BANG!!!!!!!!!wosat.

[OldGoat]

Vetus say 100 hours between oil changes. Being as it is a basic Mitsubishi underneath, this smacks of Vetus' aim to sell more oil and filters.

 

I can't see our under-stressed engines suffering if the oil is changed every 300 or so hours.

 

 

WE ? forget that synthetic oils were developed for automotive use where higher stresses, temperatures and lower viscosities are required. Modern automotive engines are made to closer tolerances and so thinner oils have been developed. In practice that means synthetics. As it happens synth: oils also work for longer - giving greater service intervals.

 

Marine engines of the type used in displacement craft are not run under high stresses and the tolerances are lower - so most likely won't benefit from synthetic oils.

Being made to lesser tolerances marine / industrial engines need their oils changed more frequently - so the long life of synths: is of little value.

 

I've no idea whether synthetics are bad for boat engines - but I can't see any point is spending a lot more for my lubricants if there's no benefit.

 

But, hey, don't let me stop everyone for spending their cash. I change my dyno oil twice a year even if it's done less than 400 hours.

[bowten]

I fitted exchange injectors to a 4cyl Kubota a couple of weeks ago,at 54,000 or so hours. Apart from normal servicing this and a new fuel lift pump last year is all the engines ever required. Most of its use is 6 hours stationary daily battery battery charging out of gear during the winter and cruising all summer. The engine is still in excellent. BANG!!!!!!!!!wosat.

Thank God I got a Kubota fitted this time.

[Timleech]

I fitted exchange injectors to a 4cyl Kubota a couple of weeks ago,at 54,000 or so hours. Apart from normal servicing this and a new fuel lift pump last year is all the engines ever required. Most of its use is 6 hours stationary daily battery battery charging out of gear during the winter and cruising all summer. The engine is still in excellent. BANG!!!!!!!!!wosat.

 

Presume a typo or a Bizzardism.

 

Tim

[Guest]

Vetus say 100 hours between oil changes. Being as it is a basic Mitsubishi underneath, this smacks of Vetus' aim to sell more oil and filters.

 

I can't see our under-stressed engines suffering if the oil is changed every 300 or so hours.

I leave our Vetus for 200Hrs on our summer outing. I always feel that the most important oil change is just before winter (assuming the boat is winterised.)

[Biggles]

Vetus say 100 hours between oil changes. Being as it is a basic Mitsubishi underneath, this smacks of Vetus' aim to sell more oil and filters.

 

I can't see our under-stressed engines suffering if the oil is changed every 300 or so hours.

 

Mine is Vetus but it's the Duetz light truck engine. 4 cly 4L 114hp. The service is 50 hours. Then 150 hours then every 250 after that. I can bowl along nicely at 4mph at 1000 rpm and about 6 mph at 1400. On tick over I get a around 3 at 780rpm, so you can see the engine is not working hard at all. Infact putting in gear sets us off and the tone of the engine doesn't even change. Either a very quick governor or more likely plenty of power even at tick over.

[bizzard]

Presume a typo or a Bizzardism.

 

Tim

What the 54000 hrs? this is correct the owner has had the boat for over 20 years and uses it intensively.

The owner told me this, i've not looked at the counter but have no reason to doubt him knowing how much he runs his engine. No one will moor near him.

Edited July 8, 2012 by bizzard