How do you know if you need to add DEF?

With being relatively new to the sprinter world (and a general lack of automotive experience) I apologize if this is a very basic question.

We have a 2008 Dodge Sprinter with 30K miles. I was at Home Depot and saw a sale for Blue DEF at $11.97.

1) Do I need to add this to my van? Which years/models need it added? Will my van notify me with a signal light?

Travis
Fear Yeh not SIRE !!
Your 2008 Sprinter is not a Blurrtech, so it does NOT take DEF fluid.
If you want those experiences you will have to buy a later van say 2010 onwards model.
Keep on trucking Sir Galahad and be "gladyouhad" a 2008 model.
Cheers Dennis

To translate Dennis from, well, Dennis into plain English

Your 2008 Sprinter does not use DEF. 2010 and newer models use it. So you do not need to worry about DEF.

The OP's logical first question should have been: "Why can't I find WHERE to add DEF?"

Or, "where did I put that 2008 Sprinter Owner's Manual?" I keep meaning to read it one of these days.....

https://sprinter-source.com/forum/showthread.php?t=4286

2008 owner's manual: http://www.diysprinter.co.uk/reference/2008-Sprinter-OwnersManual.pdf

many handy things: http://www.diysprinter.co.uk/reference/

--dick