[bwdbrn1]

I Googled "2008 Toro models", and came up with Model 20065. You can get a parts breakdown from Toro here;
https://lookup3.toro.com/partdex/index.cfm?xCaller=Toro&lang=us_en

Choose a serial number from the batch and get a manual from Toro here;
https://lookup3.toro.com/request/request.cfm

If this is your mower, it has this engine on it. Briggs and Stratton 124T02-0161-B1

Here's the manual for it.
http://bsintek.basco.com/BriggsDocumentDisplay/default.aspx?filename=iorpzOJU0HvjhJvcv4

It should take 18 to 20 oz of oil.

If it isn't the right one, the model and serial numbers should be on a label near the back of the deck.

Hope that helps.