Lexus_g3

Noticed several months ago that I was consuming oil on my GS 300 (48,000 miles) between changes. The engine is clean top to bottom and shows no signs of leaks. The Dealer?s head mechanic recommended an oil change and then reevaluate after 4,000 miles. Brought the car in yesterday?2/3 qt. low! Mechanic seemed puzzled and called Lexus Tec. support for warrantee advice. Lexus told him that the consumption was normal and therefore, not covered.
Has anyone else experienced the same? I believe that the oil is SAE 5W-30. Could the lower viscosity oil be prone to evaporation?
Thanks,

hvelador

i got a gs400 and after i run it for a couple of thousand miles or so, i do notice a drop in the oil, not a lot, maybe from full level to 3/4, which seems to be normal according to what the dealer said (makes sense due to normal driving conditions)...now if the oil level were to go close to the minimum level, i would think that would be abnormal.