hi guys,

i need info.... according to the manual, the rear differential requires a gear oil with API GL-4 SEA 90 rating. 2 years ago, i bought Mobilube HD 80W-90 API GL-5 at Hyundai Ortigas(Cyber Cars, Inc) because according to them API GL-5 is suited to LSD equipped rear axles. which i think it true.... on other Hyundai dealerships they mix API GL4 SAE90 and API GL5 SAE140 to obtain an API GL-5 SAE90 viscocity.... from the year 2005 up to now, my van was driven 50T kms already and have replaced the differential oil with Mobilube HD 80W-90 twice already without noticeable effect....

my concern now is: do i have to follow the owners manual which specify API GL4 SAE90 gear oil or should i stick with API GL-5 SAE90 such as the one offered by Mobil multigrade oil or the Castrol axle oil API GL-5 SAE90? please take into consideration that starexes are equipped with LSD rear axles...

i hope you can enlighten me more on this matter.