Welcome to the Vulcan madness Roy. When you have a minute, stop over on the newbie checkin and introduce yourself. Tell us a little about yourself and your scoot. If you fill out your profile on the user cp, your location shows up with every post too.
Is this your first bike? Have you been riding it for a while, or did you just get it? I believe the rear tire on my bike is the same as yours, but I am chair bound at the moment and can`t go check it. I may not be the best person to comment on motorcyle tires and their handling characteristics, but I am happy with with mine during the limited riding time I had before my accident. (Newbie mistake of fixating on the obstacle and dragging my leg for 50 feet along an exit ramp guard rail, instead of looking to the right where I wanted to go.)
I will eventually ride the tires to the end of their natural lives. I am strongly considering going to the "darkside", and putting a car tire on the rear wheel of my Vulcan. craznurs ran a Vredestein 165HR-15 on her vn700 for 15K miles before selling it, and it was not even half worn out yet. She is now riding something like a 1600 cc V-Star on a car tire, and says she will never go back to a mc tire on the rear wheel of a cruiser. I`m not telling you to do that, just informing you about an option available if you want to try it at some time. Most darksiders are on bigger cruisers, but there are 2 or 3 vn700 or 750`s I have read about.
Here is a good story and explanation about the darkside, if your are interested:
You will get a lot of vn riders buying Mettezler 880 tires, a few going for the less expensive Kenda Kruz, and I suppose almost every other tire available that fits. I don`t recall a lot of talk about Dunlops lately, but I may have just missed it.
You can change out the rear 150/90-15 for a wider 170/80-15 with no other mods if you are so inclined. Likewise the front tire can be changed out from a 100/90-19 to a larger 110/90-15, which will almost make the speedometer read the correct speed.
Here is a link to the Vulcan verses and a few threads about tires. Happy reading.