Diesel Engine Oil

[Lou_tribal]

Slo-Mo, thank you for your comment on oil makers’ technology, diligence. Fleet operators study oil performance, fuel, additives, etc., and that keeps oil producers competing hard to produce better products - and we all benefit.

So, with your industry expertise, do you use and recommend synthetic engine oil in marine diesels? If so, do you use the same viscosity as with mineral oils? Is their a brand that you prefer? (My choice is synthetic @15W40, either Mobil 1 or Shell Rotella T6.). I expect less carbon over time and imperceptible wear advantage as major oil companies advertise that less wear and friction with synthetics.

Why would you expect less carbon, please elaborate.

L

 

[NCheaven]

Good question, Lou. Both Rotella and Mobil 1 websites claim less sludge and Mobil 1 claims fast existing sludge reduction. I have seen reduced smoke at start up in my Volvo TAMD41P-A. My 20 year old gas truck (Chevy HD, 256,000 miles) oil was far cleaner after switching to full synthetic years ago. Going on the premise that sludge is mostly carbon with some precipitates from mineral oil, synthetic oil removes carbon buildup in the engine. Better lube performance as the engine warms reduces gasses blowing past rings. The Rotella and Mobil 1 websites are pretty interesting (especially on cold, rainy winter nights after football season) with direct comparison between synthetic and mineral oil. One includes specific test results. But, I do want to hear from Slo-Mo as an industry expert, which I am not - just a fan. BTW, my Dad managed specialty chemicals for Exxon Refining during his career, so I have been attentive about motor oils and such much of my life, driving cars and my truck to lingers lives than most folks, etc.

 

[BonesD]

Just to follow up after about 30 hours on the new oil the color has darkened but still looks fresh. Nothing like you would expect. More like the stuff in a lawn mower that seems to last for years.
Cheers all.

 

[Tiffany]

Slomo, The CEM oil flush is not added to a regular oil sequence, but as a short ~45 minute oil and filter sequence, followed by fresh clean oil and filter. Similarly, their FTC Decarbonizer is a fuel additive, not put into the crankcase. The Perkins T6-354 (4,200 hrs.) burns very clean, far less blue smoke on cold and clear once at operating temperature.

 

[Slowmo]

Slo-Mo, thank you for your comment on oil makers’ technology, diligence. Fleet operators study oil performance, fuel, additives, etc., and that keeps oil producers competing hard to produce better products - and we all benefit.

• So, with your industry expertise, do you use and recommend synthetic engine oil in marine diesels? If so, do you use the same viscosity as with mineral oils? Is their a brand that you prefer? (My choice is synthetic @15W40, either Mobil 1 or Shell Rotella T6.). I expect less carbon over time and imperceptible wear advantage as major oil companies advertise that less wear and friction with synthetics.

• 
  
  The answer is no, I don't recommend synthetics for boats unless the engine manufacturer specifies them. I don't have anything really against synthetics, its just that I also don't see that they'd offer much benefit in this operation. If I were to use one I would strongly recommend staying at the same viscosity as recommended for the engine. Contrary to popular belief synthetic base stock offers no intrinsic wear benefit. Most of the claims associated with the major synthetics is derived from the additive system. These products are flagship products so the marketers have specified higher performance targets for marketing differentiation. To be honest, in the real world these won't really be meaningful. The tests used to test oils test the extremes of of the operational envelop. Our engines don't begin to approach these limits.
  
• A comment on oil leakage that has often been attributed to synthetics. It is true that early synthetics from the 1970's did have seal shrinkage issues due to the nature of the base oil. However this is long past. In fact ALL modern top tier diesel engine oils use what amount to synthesized base oils (e.g. Chevron's IsoSyn). Due to this the difference between 'conventional' and 'synthetic' base oils more marketing than anything. However top tier oils including synthetics have very 'heavy' additive packages. So it's conceivable that the high dispersancy (nitrogen based polar detergent that keeps things clean) could trigger some leaks if it cleans up something that was helping prevent leaks. That said all these oils have to pass seal compatibility tests.
  
  To be clear, I have tremendous respect for XOM's Delvac 1 and Shell's Rotella T6, as I also do for Chevron Delo 400 etc. The only thing I don't have respect for are the small peddlers of synthetic 'miracle juice' (you know who they are).