Changing to (or from) Synthetic oil

My Toyota dealer will only put synthetic in by the third oil change, that would be at 15,000 miles. Rightly or wrongly, these guys are ultra conservative. They could make more money on synthetic oil changes.

You can go back and forth from regular to synthetic repeatedly with no problems. Also, as pointed out, some cars come with synthetic as factory fill.

From Docnick: “Unless you have an extremely high performance engine, you can use either synthetic or mineral oil under mormal driving conditions.”

No you can not use either in our particular case. The engine is not, in my view, an extremely high performance engine but the owner’s manual for our new car specifies that synthetic oil must be used. If there is a mechanical problem with the engine and dino oil is found present and yes, they can tell the difference, then the engine warranty may be declared invalid.

Doesn’t say that on the Mobil 1 site. Actaully it says,

“To meet the demanding requirements of today’s specifications (and our customers’ expectations), Mobil 1? uses high-performance fluids, including polyalphaolefins (PAOs), along with a proprietary system of additives. Each Mobil 1 viscosity grade uses a unique combination of synthetic fluids and selected additives in order to tailor the viscosity grade to its specific application.”

Since it says its made from fluids, that shows its not mde from oil. The site is pretty extensive. Mobil also shows its conventional oils on its site, too.

I was referring to the Kia; I don’t know what make and model your car is, but if the manufacturer specifies synthetic only, then, of course you should use that.

Please keep in mind that oil and oil change intervals in many European cars have little to do with engine perfromance and durability, and much to do with wanting very long drain intervals for environmental reasons.

“Since it says its made from fluids, that shows its not mde from oil.”

Ummm…I hate to shock you, but “fluid” simply means anything that is liquid.

Water is a fluid, crude oil is a fluid, blood is a fluid, etc. To say that the statement on the Mobil website “shows that it is not made from oil” is not valid reasoning. It might be made from oil, or it might not be made from oil, but unfortunately, the use of the word “fluid” is just too non-specific to allow anyone to form an opinion, IMHO.