TAMD41P-A smoking at start up
Mine did smoke some when starting for a few years. Last year I switched to Full Synthetic 15W40, and as of the last few trips down we don't notice smoke when starting now. We'll see if that changes when cooler fall temperatures come along, but so far, we just haven't noticed smoke - Admiral and I mentioned that in our last conversation about the boat. (2005 Camano, 1700 hours)
What we have noticed is that cruise RPM generates slightly less coolant heat per the gauge, same for 3200 and higher RPM, just slightly less temp than before. The engine runs smoother and quieter, too. Top brand synthetics Rotella and Mobil 1 both claim cleaner engines, more carbon removed, and all sorts of things. Their product sites have ample statistics and truck fleet testimonials. Of course, when I asked Volvo USA, they said to always buy Volvo products, but the truck fleet managers all swear by full synthetics. And, both Rotella (Shell, but you already know that) and Mobil1 (Exxon) are both qualified for a certain Volvo oil certification per the oil containers. A tribology (study of lubrication) association's tests support Synthetics' claims.
I don't want to start WW 3 over oil selection, but one of you mentioned smoking, and using a full synthetic has cured my smoother running, quieter TAMD41P-A of most of the smoking.
I'm looking forward to seeing what this fall's oil change accomplishes in terms of the new oil taking longer to turn fairly black. In a 17 year old Camano mostly run at slower RPM (total gallons on fuel fuel scan meter divided by total hours on engine gauge panel shows about 2 gallons per hour over the boat's life. I did have sludge partially blocking my exhaust in 2018, mechanic dug that out, and I cruise slightly faster most days, run 10 or so minutes over 3200 and maybe 3 minutes at WOT to clean my exhaust system late in the day - probably not long enough and hot enough, but it's a start. Anyway, I am sure I've had plenty of engine sludge, and I wonder if the full synthetic will improve how much of that is picked up and carried away with oil changes. I'm sure it will take years, but I'll be watching the new oil after this fall's oil change. We've had mostly Valv-Tect fuel for the last 3 years, and perhaps that helps, too. I've used Biobor JF "shock level" biocide additives since a nasty 2018 post 2017 purchase 3x fuel polishing. Biobor may have helped keep the fuel tanks cleaner and when I cut open my last primary Racor used filter it looked like new inside afte 80 hours. Anyway, less smoke, engine working well.
Anti-Synthetic engine oil boaters, fire away, make hex marks, tell me how your grandfathers and you use straight 30, take your best shots at my choices! Truthfully, if your choices have produced good results, congratulations! Good results are what we're all after.