Synthetic Engine Oil for Diesels

[tcm]

These are highly regarded in some quarters. Apparently they reduce friction, increase power, some report another two knots and so on. But not recommended till say after 300 hours when engine is properly run in. Has anyone any direct, indirect or anecdotal evidence of using the stuff? What brand and so on?

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[jfm]

Often thort about this but have not bothered in the boat becos volvo warranty insisted 100hour oil changes, and that is far inside the range of mineral oil let alone synthetic. Synthetic is 3x cost but lasts easily 3x as long, so not really more expensive, so should be worth having. But if warranty insists on same change intervals, what's the point?

It is nice clear stuff, looks the part and obv you would not use anything else in a fast car. Talk of extra 2 knots etc is obviously bolx. That's an extra 300bhp on D2 and there's no way the lower friction will release 300bhp. 10 bhp praps, but you wont notice the speed difference on that.

Mobil 1 is the biggest car brand. This is a 10-40 I think. Castrol do lots, including 0-40, 10-40 and a 10-60. There may be loads of others.

Actually I would think it might be more use in the gennys as they run for hours and hours, and you can disconnect the hour meter without worry, if there is any whinging from the service people about change intervals.

Some people say if you change from mineral you have to dump the first fill of synthetic immediately, to flush it all. Massive £££. I would guess that is bolx, as there is actually mineral base oil even in synthetic so no reason why a trace of mineral in synthetic will cause any prob, imho.



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[hlb]

I used to have it in mine. Mainy because the bloke before had it in.Anyway mechanic stuck ordinary stuff in last year so it's reverted to that. I dont think theres much advantage in a boat cos it's main benifits is longer periods before changing. With a boat your changing it every year anyway.

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Haydn

 

[Guest]

Imho Synthetic oil is best used where it is important to know the diagnosis reference your engines/equipments wear as you go along. by taking oil samples. i.e ferrous content, rings and bore, copper, bearing surfaces etc. Then the cost is more effective. Mainly used in plant where large volumn and long time periods between changing is required and commercially possibly. vehicle fleets, grid generator gearboxes and the like
Rob

<hr width=100% size=1>robinwdunham

 

[tr7v8]

Comments but not necessarily from a marine perspective.
Synthetic shouldn't be used before engine is FULLY run in as it can stop components bedding in speciffically rings and bores.
Unless engine is in 100% top nick oil consumption can increase both from burning (oil getting past rings) and from leaks.
Diesel engines always have ring blow by it's the reason the oil turns black as coal (carbon) straight after being put in.
Because of the above diesel oil has a much higher detergent ratio than it's diesel equivalent.
And this is generally why a diesel has shorter service intervals than a petrol (or should!)
Diesels run cooler as regards exhaust gases than a petrol, one of the reasons for running synthetic is that mineral oil can fry in the bearings of the Petrol Turbo unlikely in a diesel.
In normally asperated engines extreme tempratures and pressures are less likely Synthetic generally is used for the high temp and high pressure.
Finally as regards longer service intervals do you really want a sump full of a year old engine oil sitting in it over the winter ready for the spring start? If not then I'd suggest longer serice intervals probably wouldn't apply to 99% of pleasure boaters anyway.
Mobil have done a brilliant selling job on Mobil 1 and synthetic oil & I'd suggest with certain exceptions a lot of cars don't need it!


<hr width=100% size=1>Jim

Draco 2500

 

[jfm]

I know it is often sed that synthetic should not be used in new engines till fully run in, but how come all high performance car manufacturers fit synthetic oil from new?

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[wakeup]

Good point.....

Although I was told not to run the engine in when I had my new porsche, I was required to take it back to have the oil changed at 1000 miles. I know that it has always had Mobil 1 init so I guess something happens to it during the first 1000 either that porsche expect a lot of swarf to be pushed out into the oil, worrying thought in iteself???

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[jfm]

Re: Good point.....

I think there is a lot of swarf in first 1000 miles but it should all be in the filter and not slooshing around (fortunately!). But I dont know of any serious cars that use mineral for the first few 000 miles then switch to synthetic, so I'm not sure about this running in thing......

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[tr7v8]

Most Porsche engines have Nicasil bores and I'd guess probably fairly high tech rings to go with it. This is the main issue of running in on synthetic so I'd presume that could be a way round it. Also I suspect a lot of these hand built type engines are dyno run once built so that could take care f some of the running in issues. The running in period these days tends to be of the don't cane the "nuts off it" probably to give ancillary bits time to bed in like brakes. Some engines run very high initial oil temps and they've kept a running in oil which gets changed at around 1000miles. I know of at least 2 Peugeot engines which have been killed by missing this first oil change.

<hr width=100% size=1>Jim

Draco 2500

 

[wakeup]

Are you saying a porsche ain\'t a serious car??

hummmmbugggg

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[jfm]

Re: Are you saying a porsche ain\'t a serious car??

Not at all, and I dont see how you could think I was! All I said I dont know any serious cars that use mineral then switch to synthetic, thus I question the advice to use mineral in a new boat diesel. Serious cars here means porkers included.

They can be a bit hairdressery though.......

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[byron]

Re: Are you saying a porsche ain\'t a serious car??

<font color=blue>I thought Porsch was what one put in a sausage.

<hr width=100% size=1>http://www.alexander-advertising.co.uk

 

[wakeup]

Wakeup storms off with hairdryer uner one arm - NM

&

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