Oil question

[Futzee]

Recently bought a used Trailblazer for my son and looking over the service records it seems the previous owner used a synthetic blend when changing oil. My question is I'm pretty sure I can't go back to conventional oil but is it okay to switch back and forth between the synthetic blend
and full synthetic oil? The reason I ask is that Napa has a great special on full synthetic but normally the blend will be cheaper. Just curious about it for future reference as I've always used conventional oil so synthetic of any kind is new to me. Thanks for your help and love this site.

 

[Eddie]

You can go back to conventional oil.

 

[Clevy]

The whole idea of not being able to go from syn to conventional is false. Synthetic blends wouldn't exist if that were true.
You can use any oil you want whether its synthetic or conventional so use your favorite and don't sweat it.
The oil change minder is based on conventional oil use so just follow it if using conventional. If you want to use a synthetic then you should be able to extend the drain interval. 10000 miles is easily doable with a quality synthetic unless you've got blow by issues or a problem in general with your engine.

 

[EricF]

thankfully with blended oils, myth debunked!
I still get people telling me you can't mix or can't go back to conventional, etc.. etc.. etc..
so when I ask them what a blended oil is, they will either NOT know or tell me half synth, half conventional, and I correct them, not half, but it has synthetic in it. Myth debunked.
The lightbulb turns on! Then they start to question more things they thought were true.

You can go back and forth all day long. I wouldn't worry about it. If anything, stick with a blended oil and go 7500 OCI and not worry about anything.

 

[2KBMW]

Futzee. No problems at all to switch.
Enjoy our forum.

 

[DanielinTheLions]

I've gone back and forth between synthetic and conventional in my Prism and Dakota. In fact I've used conventional, synthetic, and blend in the Dakota it at various times. I don't think you'll have any issues with your switch between blend and full synthetic plan and I think you'd be fine to go back to conventional too.

 

[Donald]

But if you go back and forth with synthetic oil more than twice your engine may fall out when accelerating.

 

[Merkava_4]

How synthetic is synthetic oil anyway? If it was really that synthetic, it wouldn't
mix with regular oil. Just like water based paint doesn't mix with oil based paint.

 

[y_p_w]

Originally Posted By: Merkava_4
How synthetic is synthetic oil anyway? If it was really that synthetic, it wouldn't
mix with regular oil. Just like water based paint doesn't mix with oil based paint.

That something is a synthetic hydrocarbon has nothing to do with whether or not it mixes with a refined mineral oil. There are also many different types of synthetic hydrocarbons.

 

[Clevy]

Originally Posted By: Donald
But if you go back and forth with synthetic oil more than twice your engine may fall out when accelerating.



That's pretty common when switching back and forth. I've read that lately some folks have run out and started their cars to let them warm up a bit. By the time they were ready to go their engines were gone. Apparently they dissolved because they were using a 20 grade.
I keep an oil catch pan under my car at all times now just in case. When an engine dissolves it makes a huge mess so I want to keep clean up as easy as possible,just in case.
Can't ever be too careful right.