my car is a 1995 corolla XL, acquired it 4 yrs ago. annually ang change oil ko since then, using shell helix semi-synthetic or castrol magnatec (semi-synthetic). nabasa ko sa thread parang common ang 5000 kms or 6 mos change oil, malaki ba ang epekto sa makina kung annually ang change oil? kasi nag aaverage lng ng 2000 to 3000 kms ang tinatakbo ng auto ko yearly, tsaka luma na rin naman ito.