What type of motor oil does a 96 Lexus 300 series use

Probably the same as most other cars, 10w-30. Depending on the mileage, you may want to consider going synthetic.

Also check your owner is manual book for the recomendation.

10w-30 is the standard. lexus dealers use mobil oil. if you have high mileage use synthetic oil or mobil for high mileage.

The Owner is Manual says what weight. The type is up to you. Is fine to use synthetic but is pricey around $6 a can. Stick to the intervals on oil changes and will be affordable to do. Local quick lube shops charges around $50 for an oil change with that type. Petroleum base oil is much cheaper and runs about $20~$25.

10w30, if not sure, it is written on the cap itself. Just open the hood.

the weight is 5w-20

5w-30 is the standard motor oil for all Lexus vehicles, including all new models.