We are also rather old and our View is our first diesel. Fuel mileage with toad at 55 MPH is 15 MPG, and without toad at 65 MPH is 15 MPG. Our toad is a 1991 Daihautsu ROCKY.
I do all the service that I can myself. Oil changes can be extremely expensive at the stealership, but I do my own. Every fluid has a specification per M-B and you should be aware of them.
Ours also has the 3.0L Turbo diesel engine and I have had only two problems with it. The first was a glow plug failure, not a really big deal and it ran fine, and I got it replaced after the trip.
The second was an EGR valve failure, causing the turbo to get no exhaust drive. I did nurse it home at low speed.
M-B Specs list: http://bevo.mercedes-benz.com/bevolistenmain.php?language_id=1
Oil filter wrench: https://www.amazon.com/gp/product/B003QHQW8I/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
M-B approved oil: https://www.amazon.com/gp/product/B000GAP428/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1 (you need 3 of these)
M-B approved oil filter: https://www.amazon.com/gp/product/B001DRLPP8/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
Good luck and enjoy your rig!
