Semi Synthetic vs Fully Synthetic

Multi grade only describes that the oil has multiple temperature ranges, ie: 0 to 20, 5 to 20, 10 to 30, and so on. If you're using 0W20, it very likely is a full synthetic: such low viscosity most always is. As long as your oil changes are not extremely few and far between, I think synthetic is overrated; if an oil meets the spec, it meets the spec.

Regardless of mileage, switching to a thicker oil might worth considering, for engine longevity. I'm not really sure. In other countries around the world Toyota recommends 0W20 but also says thicker oils are ok. Perhaps try 5W30 for an oil change and see how it goes, especially for mpg?

 

Mobil 1 0W-40 for the win////

 

In the US, 0w-20 is always(?) synthetic, and the manual calls for 0w-20 synthetic. What does your manual say?

 

My manual calls for 0W-20, but doesn't specifically require synthetic. That viscosity is usually synthetic in the US---although I understand Honda sells a semi-synthetic 0W-20.

Is that a semi-synthetic in the photo? What standards do they claim it meets besides SN? What country does it come from?

Incidentally, I haven't seen engine oil sold in that type of container in many years.

 

It appears in your part of the world, Toyota recommends 5K mile interval using the oil you show in your picture. In North America, we can take advantage of 10K mile oil change interval IF we use full synthetic 0W-20, 5K mile otherwise. I'd just continue to follow the service schedule and oil grade you have been using all along. Don't overthink it.

 

I see no value in semi-synthetic oils. If you're going to use synthetic, use full-synthetic. At most you're just saving a few pennies.

 

Does your manual specifically state it must be full synthetic for the 10K intervals? Mine does not---although we might assume effectively requiring synthetic was their intention, given the rarity of non-synthetic 0W-20 in the USA.

 

No it does not say anything about "full synthetic" or not. My 2013 Owners Manual simply says, "0W-20 is the recommended viscosity" and "ILSAC GF-5 multigrade engine oil." To the point about the 5K mile oil change interval, the Warranty & Maintenance Guide (separate booklet) says, "If 0W-20 oil WAS NOT used at the last oil change, replace engine oil and filter" for the 15,000 mile, 25,000 mile and so on services, implying to me at least that unless you use 0W-20, you should change at 5,000 mile intervals. Thus, oil change interval is based simply on viscosity used at the last oil change. Thanks for calling me out to clarify. I will be more careful in the future with my statements about oil change service!

 

For what it is worth, the User Guide for my 2012 says 0w-20 is for best cold weather starting (-20F) and best fuel economy. There is no mention of it being the best choice for reducing engine wear. Since the oil film of 5w-30 is slightly thicker, that oil should do better to reduce wear and still have very good cold weather starting. You can always use an oil analysis lab to confirm the wisdom of whatever you decide.