Dang, i Usually use Shell Conventional, Supertech or anything cheap. I never lost any oil between interval with these oils but my HLAs were ticking so it got me worried. So I mixed 2 quarts of Valvoline All climate conventional SM(I got a case from a rebate at pepboys) and mixed it with 2 quarts of Valvoline Maxlife Synthetic(SL hasn't been approved by the API for some reason). its been 2,000 miles and I lost 1/4 quart, but fortunalty my HLA are alot quieter. I don't know whats worse... Louder HLA's or burning 1/4 of oil. Although looking back.. when I first bought the car(56,000 miles), I"ve was using Castrol Syntec(10w30),, but it would burn 1/2 quart between intervals, then I switched to Supertech Synthetic(10w30) and I would lose 1/2 quart too... Is it maybe because of Synthetics? Should I switch to Valvoline Maxlife Conventional? im worried that my HLA's will get louder again if i switch back to 100% conventional. Sorry for all the typign errors,, its 0626 here and I haven't slept yet. PS. I don't drive hard at all. but I do drive alot.