Reached 100k miles: Synthetic or high mileage oil?

[Jorge Dominguez]

I have been using full synthetic oil for the longest time on my 2001 ST that just reached 100k miles last week. Should I switch to high mileage oil instead or stay with synthetic?



Best regards, JD.

 

[Jon W9]

I would say that if you aren't really having any oil issues, and have been running synthetic all along, you may as well stick with it.

 

[Gavin Allan]

Stick with synthetic.



Mobil 1 5w20 with Mobil 1 filter, twice a year for me.

 

[Tom Schindler]

Synthetic oil. Those high mileage oils have had some tests causing it to lower gas mileage.





Tom

 

[Uruiah Barley]

I have 130K on my '04 and I have always used Mobil 1 synthetic. I started with 5w30 and now I use 10w30. No complaints or problems. I change the oil every 12-15K and the filter every 3k.

 

[Rodger Tellefson]

I agree to stay w/ synthetic, i.e. Royal Purple.

 

[ray moyer]

sythetic...

mobil 1 extended performance

 

[Johnny O]

Agreed. If you've always been running synthetic there is no reason to change.

Caymen is correct, if you look at the starburst on the label of a high mileage oil, on most you will not see the words "Energy Conserving".

 

[Dreman]

Synthetic at 151k and still going strong. My GMC we sold this last spring had 283k on the original engine, and I used synthetic in it. The guy that bought it is still driving it. It's irritating, because the main reason I sold it is I thought the transmission was going to go out soon!



Synthetic is better oil than "high mileage" oil, especially if you are already running it in your engine.

 

[David Ponder]

Not to hijack the thread, but I have been using Motocraft Synthetic Blend for the past 14 months I have owned my ST.. Would I benefit in mileage or less wear by switching to a full synthetic now? (My ST has 112K on it) What would be the pros and cons?



Thanks. Dave

 

[Johnny O]

Dave,

With 112k on it, nothing you do now will likely make any difference. For a normal OCI of 5000 miles or less, a used oil analysis will show virtually no difference in wear metals between Motorcraft Blend and a full synthetic oil. I have gotten UOA's that prove this myself. There are many more posted at www.BobIsTheOilGuy.com.

Motorcraft Blend is an outstanding oil for the money.