I used Tection 15W-40 for the rinse phase in both my Aerostar and my older Accord.
In the north, this late in the year, I'd probably avoid a 15W-40.
No, it probably won't hurt, and I have no problem using higher weights in any engine in warm weather, but not when I know it is getting colder with each passing day.
Did you score the Tection cheap?
I have three $3.74 gallons of Tection 15W-40 and four of Delvac 15W-40 at $3.00 after MIR.
I have exactly zero diesels at the moment, although I am always open to a nice W123 diesel.