"synthetic oil carries more heat to the heads making them get hotter than dino does thus imperiling the rings under certain circumstances"
I read all the oil threads (because they are so much fun) but this is a new one on me. I'm sure that the BMW mechanic is absolutely right, and I'm switching back to dino tonight. Tomorrow, when someone posts that synthetic is actually better because it carries heat away from the vulnerable crankshaft to the well-cooled heads, I'll switch back.
Seriously, I do seem to recall that many years ago in the early days of synthetic oils, there was speculation that synthetic didn't transfer heat as well as dino. I don't think anything ever came of that, but I'm sure others who are more knowledgeable will respond with their considered opinions.
peter '73 R75/5, '04 R1150RA
I would love to know the original source of these crazy rumors. I bought a new Porsche 911 in 2001 and it came from the factory with Mobil 1 synthetic oil. I understand that more and more manufacturer's are now filling the crankcases with synthetic oil when they leave the factories.
Think about it for a minute: why in the world would synthetic oil carry more heat and damage the heads than dino oil? It's an absurd statement, much less, to be coming from the mouth of a mechanic.
FWIW, I have used synthetic oils in my cars and motorcycles for just over 20 years and have never had one leak or problem with any of them. That includes the break-in period. My rings have always seated properly and the engines broke-in just like they would if I had used dino oil. I like synthetics because they can withstand higher heat ranges without breaking down and they leave far less deposits and carbon build-up in the heads and on top of the pistons.
But...............the rumors will continue to persist.
I think that it's crazy to think synthetic oil somehow "carries" more heat to the heads. That must be some sort of new wave thermodynamics theory that I am not aware of. However, I maintain that if BMW engineers were to think that synthetic oil was warranted, they would have specify for it. After all, they don't have any problem with specifying synthetic oil for their cars.
Cogito Ergo Vroom - I think therefore I ride.
03 Rockster, 07 Aprilia Tuono R, 07 KTM 990 Adventure
yellowjacket wrote:Boy oh boy, am I gonna get in trouble for this one...but I gotta ask;
I was told by a BMW mechanic (when I lived in FL) that he rarely recommends synth in the oilheads becuase
and this is where I need to ask if anyone has ever heard of this because I don't get it
"synthetic oil carries more heat to the heads making them get hotter than dino does thus imperiling the rings under certain circumstances"
OK, hit me guys!
Dave
Okay. I gotta ask... how old was this mechanic??? Bet he was sprouting more than a few gray hairs. Sounds like he heard a rumor and mentally grabbed it as actual fact.
I switched my Rockster to synthetic at the 600 mile service. Especially when I was told, by the service writer at Bob's BMW, that all the MD State Police BMW motorcycles get switched to synth at the same point. BECAUSE it holds up better under high heat conditions (as in, sitting in traffic on a summer day, in the DC Metro area).
fnfalman wrote:I think that it's crazy to think synthetic oil somehow "carries" more heat to the heads. That must be some sort of new wave thermodynamics theory that I am not aware of. However, I maintain that if BMW engineers were to think that synthetic oil was warranted, they would have specify for it. After all, they don't have any problem with specifying synthetic oil for their cars.
Good point however BMW has sold BMW branded synthetic motorcycle oil for a long period of time through their dealers.
It's a dichotomy, isn't it?
