Yes, you can use 20W50 engine oil for the Bajaj Pulsar 150 model 2011. The Pulsar 150 is commonly recommended to use 20W50 viscosity grade engine oil by Bajaj. This viscosity grade provides adequate lubrication and protection for the engine, especially in moderate to high-temperature conditions. However, it's always best to consult the owner's manual or reach out to an authorized Bajaj service center to confirm the recommended engine oil grade for your specific model and year. They will have the most accurate and up-to-date information regarding the suitable engine oil for your Pulsar 150.