Manual shifting 5 speed

I have 36000 miles on my 2014 v6 5 speed, I do most of my driving on my small island with lots of hills and a 45 mile max speed limit. I do try to drive every few weeks longer distances at higher speeds. My question is should I manually shift regularly to keep engine rpms at optimum levels, I have been but I wonder if this will shorten the life of the transmission.

I would say yes. I rarely use 5th gear on my van. 3rd and 4th gear most of the time keeping the engine around 2500 rpm. Once I hit over 90 KPH I shift to 5th on the flat. I find that this gives me the best mileage as well. I manually shift all the time in town starting in 2 and 3rd gear all the time.
Hope this helps..

Yup, I've been converted to manual shifting - for many reasons - due to the expertise shared by user name “sailquik” on this forum.
The attached provides his sage advice, and my own use of technology to prove he was right, and that this practice should be adopted.

Thanks for the feedback, my v6 loves to run at 2800 to 3200, so I do what I can to keep her happy.

Island Jim.
On flat roads there is no need (or reason) to run 2800-3200 RPM with your OM-642 3.0 liter V6.
Dpending on your speed, anything over ~2200 with a % Load reading of < 60 percent will get you
very good fuel mileage.
If you encounter an uphill grade, or are at a higher speed and pushing into head winds then the
2800-3200 RPM with a lower % engine load than the next higher gear will get you both the best fuel
mileage and the best performance.
A Scan Gauge II (or similar OBD-II performance monitoring device) really will help you to drive in the
most efficient manner, giving you BOTH max. fuel mileage and max. performance.
It's all about keeping the % engine Load as low as possible for your current driving conditions.
Roger