I switched to partial at 180,000 today. I figure next oil change I will go to full I used the Castrol high mileage stuff.....figured that was ok.

 

Switching when the engine is fairly new makes more sense in my opinion. Synthetic oil will make the engine last longer. At 180k the engine is already so worn that synthetic isn't going to extend the life a noticable amount. It's probably a waste of money at this point....

 

I run Mobil 1 Extended Performance full synthetic. Have for as long as I've owned my Burb. However, I have a lot less miles and agree that for you it probably isn't worth the extra cost. Sticking with a blend is probably alright though. They aren't much more expensive than conventionals.

 

I guess it just made me feel better to run something "better" in there haha. It has been such a good vehicle and just wanted to feel like I am doing preventative maintenance to her. We have put almost 60,000 miles on it since we bought it and I want to take care of it.

 

I've been running Mobil 1 since day one when I bought my Tahoe in 07. Now has 156K on it and doesn't burn any oil. Maybe 1/4 of a quart over 8k miles.

 

Spend an hour or two reading HERE to learn all you wanted about motor oils.

I think, my summary, is that if you change your oil at "normal" intervals...that is, before the additives break down, you are fine. If you want extended drain intervals, then a synthetic will provide better lubrication for a longer interval.

 

I have been running Mobil 1 in the burb since I purchased it at 18,000 miles. The truck now has 50,000 in the year and a half we have owned it. My wife's equinox has only seen Mobil 1 since we purchased it new in 2011.

 

Mobile 1 full synthetic in my 07 since new...97,000 and no oil consumption issues... I agree that if you have used dino oil switching at a higher mileage to synthetic is probably not going to buy you anything...

Synthetics do improve MPG more so than dino, however its over a period of time not instantaneous the minute you change to it....this is why GM and other auto makers are now requiring a synthetic blend or full synthetic in many new vehicles I point this out as many folks just assume oil is oil... if you own a 2011 and up I strongly suggest you read your owners manual on what oil is required as you open yourself up to voided warranties due to the wrong oil being used....

NOTE: using dino oil when synthetic is called for won't hurt anything but synthetics do have properties that help improve mpg and reduce emissions along with reduce engine wear...
I believe all newer Corvettes require full synthetic but also note that the Corvette also uses the same spark plug as your Tahoe or Suburban...

And a second note: Yes you can mix dino and synthetics....

 

Great information here. I've never experienced any oil consumption so maybe I'm lucky.