I would say that if the tag on the machine specifies this oil then it's probably what you want to use.
Grainger is about the highest cost supplier there is.
Here's the results of an eBay search I did for this oil and it looks like you can get it for under $20 a gallon with free shipping.
If you buy a 5 gallon pail it can be even less expensive.
http://www.ebay.com/sch/i.html?_trk...kw=mobil+dte+oil+light&_sacat=12576&_from=R40
BTW, I was just recently made aware of these Cazeneuve lathes and I'm really liking what I read about them.
How do you like yours?
Any information would be appreciated.