using slight mount of oil

[gj]

have a hyundai accent,114,000 miles. using mobil 1 it would use about a qt every 3,000 miles,no big deal i know.so i tried Castrol GTX High Mileage 10w30,made it to 3,600 miles went down 1/2qt.so not leaving well enough alone last change i went with trop artic 10w30 .now it's used about 1/2 qt @2,000 miles.the trop artic seems to make engine run better ect,than the gtx hm.it had a cold start knock for a few seconds its gone,due to a wix filter i guess.
is it due to the semi and syn oils being thinner than conventional oils is the reason for the oil use?the car doesn't smoke,and runs great.and is it the fact that the Castrol High Mileage isn't energy conserving is why the trop artic seem to make a smoother running engine?

 

[AndyH]

The Trop-Artic is probably thinner at operating temp versus the Castrol GTX High Mileage oil. I guess you need to decide if you'd rather have the "better" performing engine with the Trop-Artic and have to add a bit more oil, or have less oil consumption with the Castrol GTX High Mileage oil and a "worse" running engine.

 

[gj]

i guess what i'm trying to ask is:why would a "thinner" oil cause the extra consumption? does it wear out?

 

[bar1]

If you don't see any external oil leaks, oil 'leaks' into the combustion chamber and gets burned together with the gas.
Your cars oil consumption is normal.

 

[427Z06]

What you observe may not only be due to the difference in the viscosities of the oils. It could very well be due to other things such as metal-wetting properties or volatility.