Tom F&L GoR
Enthusiast
Many of you send me *** with oil questions. I will answer to you personally, but I think I will also put up my answers as a new thread. Feel free to send me ***, my User CP is set to bounce it to my email so I will respond more quickly to you than to a new thread. I'll hide/change the names to protect the innocent. I just hope it doesn't swamp me...
Quote:
Originally Posted by xxxx
Hi Tom,
I recently purchased a 2010 Acura TL as a daily driver and it uses mineral oil vs synthetic. They said it is fine to switch to synthetic as long as you keep the same weight (5-20). It only takes 4.5qts and I was thinking to switch to synthetic after about 500 miles. Addtionally they state only change oil when the computer tells you
. I drive 25k plus miles a year so I would like the engine to last.
Sorry for taking your time, but everytime I read one of your posts I learn something new.
Thanks,
xxxx
It is fine to switch mineral and synthetic and back again anytime. The only reason the dealer said to keep the same weight is sort of legal - they must adhere to the oil grade that provides the fuel economy rating the car is sold under.
While under some circumstances (below 0F) the synthetic will be better, under most circumstances, the engine cannot tell the difference. A 5W-xx is a 5W-xx no matter what base oil, and so cold start and pumping characteristics are by definition the same. Also for high temperatures, the xxW-20 is a xxW-20 because that is the definition of that second number in the SAE viscosity grade system. At extremely high temperatures (>275F) the synthetic oil itself may be more durable, but at those temperatures the antiwear and friction reduction additives make the difference between good and average oils. With a commuter car, I doubt you will experience this.
I can't make up a reason why they would tell you not to change the oil earlier than the computer says to. It might be "wasteful" but cannot be harmful. In fact, keeping the freshest oil in the engine is the secret to longevity.
If your car's service life is best described as a few longer trips/day (vs. many short trips) then that is an easy life for the oil. Startups are few, the oil needs 30-40 minutes to get to a temperature high enough to boil off the water that accumulates (water upsets many oil additives) and the operation is inside the window that the oil performance is designed for. If this is accurate, I would suggest the Mobil long drain oils (I think they have a 5000 mile and a 7500 mile oil) that are actually mineral oils. Then let the computer tell you when to change. If your service is more stop and go, perhaps the synthetic is a better choice since the degradation from contaminants is more rapid, although I would still only change oil every 5000 miles.
If some of this didn't make sense or you are curious, let me know - be happy to explain further.
-Tom
Quote:
Originally Posted by xxxx
Hi Tom,
I recently purchased a 2010 Acura TL as a daily driver and it uses mineral oil vs synthetic. They said it is fine to switch to synthetic as long as you keep the same weight (5-20). It only takes 4.5qts and I was thinking to switch to synthetic after about 500 miles. Addtionally they state only change oil when the computer tells you
. I drive 25k plus miles a year so I would like the engine to last.Sorry for taking your time, but everytime I read one of your posts I learn something new.
Thanks,
xxxx
It is fine to switch mineral and synthetic and back again anytime. The only reason the dealer said to keep the same weight is sort of legal - they must adhere to the oil grade that provides the fuel economy rating the car is sold under.
While under some circumstances (below 0F) the synthetic will be better, under most circumstances, the engine cannot tell the difference. A 5W-xx is a 5W-xx no matter what base oil, and so cold start and pumping characteristics are by definition the same. Also for high temperatures, the xxW-20 is a xxW-20 because that is the definition of that second number in the SAE viscosity grade system. At extremely high temperatures (>275F) the synthetic oil itself may be more durable, but at those temperatures the antiwear and friction reduction additives make the difference between good and average oils. With a commuter car, I doubt you will experience this.
I can't make up a reason why they would tell you not to change the oil earlier than the computer says to. It might be "wasteful" but cannot be harmful. In fact, keeping the freshest oil in the engine is the secret to longevity.
If your car's service life is best described as a few longer trips/day (vs. many short trips) then that is an easy life for the oil. Startups are few, the oil needs 30-40 minutes to get to a temperature high enough to boil off the water that accumulates (water upsets many oil additives) and the operation is inside the window that the oil performance is designed for. If this is accurate, I would suggest the Mobil long drain oils (I think they have a 5000 mile and a 7500 mile oil) that are actually mineral oils. Then let the computer tell you when to change. If your service is more stop and go, perhaps the synthetic is a better choice since the degradation from contaminants is more rapid, although I would still only change oil every 5000 miles.
If some of this didn't make sense or you are curious, let me know - be happy to explain further.
-Tom
