hey is it bad to change from sythetic oil to regular oil at like 30000 miles?? thanks for your help

 

The answer is "like" no, if the car has been reasonably well maintained. If you look into the oil fill and see any sludge, you might might to use an Engine Oil flush product first, just be sure to follow the directions very carefully. The superior detergency of synoils will break up this debris over time, but it will also make your expensive synoil dirty faster.

If it were me, I would go to a shop that has either a BG products or a Bosch "engine flush" capability, and pay them to run it through your engine to prepare it. Then you will be assured that the car is clean and no harm will have come to it from the cleaning process. But this is optional, and the service is not cheap.

It's the same as going to the dentist - they carefully clean your teeth first, then do the inspection, then coat with fluoride.

 

--> MOVED TO UNDER THE HOOD <--

 

I think that you may be reading 9krevz01's question backwards, RoadRage. I agree that you could be concerned about sludge when switching from dino to syn, but I don't see how switching from syn to dino has the same issue.

The biggest concern I've read (but honestly can't speak from experience on this) is that the switch may cause some seals to leak a little. That's because esters used in some synoils swell the seals. If you do switch back to dino, you should keep your oil change intervals fairly short.

 

Why go back to Dino?

 

[QUOTE]Originally posted by slalom44
I think that you may be reading 9krevz01's question backwards, RoadRage.

 

I have seen cases (UOAs) where increased where occurred when switching back to dino after sustained use of the same syn as well as occurences where people frequently switched oil brands. But more so when a constant of the same syn oil was used for a period of time.

It is not to say that it will not stabilize yet evidence has shown that a wear spike will occur during the switch.

 

[QUOTE]Originally posted by Prancing Horse