As to the different tread edges.
I do not know about the White Outlines. That is to say, i do not know what tread edge comes w the white outlined tires.....or if both styles come with the whites.
But.
I do know that somebody is blowing smoke if they say that the different tread edge comes only with a 17" tire.
I had all 4 MOUNTED and, I have (Surprise!) 18" wheels. Yep! All 4 of them. And one of them was the smooth side. I ended up with 4 matching serrated edges and they look good IMO.
I now have about 500 miles on the CTs and can tell you that
the dry traction is awesome and saved my family from a bad accident a couple of days ago in Sarasota. A young girl in a small red car (Japanese econobox of some sort) was talking on her cell phone. She was driving in the left lane of a 4 lane road (University Road exiting Sarasota) And I was driving in the right lane.
She decided to change lanes and just drove right over me. Or she would have.... I YANKED the wheel at the last minute and took it on the shoulder (at 50MPH) and she missed me by about 1 inch.
The tires screeched a bit, but the turn was like I was on rails.
BTW She never saw me. She had no idea that she nearly killed all of us.
The wet traction finally got a work out last week, Fairly heavy rain (!/2" in 1 hour) and the car is much better at 70MPH in the rain than it ever was with the Goodyears. The Goodyears were always on the verge of hydroplaning at 70, and I had to back off to maybe 60.
The only bad news is the MPG.
Coming back from Ft Lauderdale today, I filled up with premium as usual at the east end of Alligator alley, set the cruise on 75 and proceeded to the west end of the Alley at Naples, and on to Ft Myers exit on the interstate and filled up again. It took 5.4 gallons for 117 miles.
21.7 MPG.
This represents a slight gain over the Bridgestones that I tried, but still represents a MAJOR loss of MPG vs the worn Goodyears. I always got at least 24.3 MPG with the GYs at 75 MPH on the interstate.
I can only give props to GY for building a very nice, quiet, good dry traction, Low Rolling resistance tire.
Of course a WORN tire, with all other things being equal, will provide better MPG than a fresh High Tread tire. So I would guess that as the CTs wear out the MPG would improve slightly.
I am quite upset at the AMOUNT of penalty that is being extracted by the CTs, but otherwise I like the tire.
It is simply safer than the GY.
Of course, I cannot comment on
1- snow characteristics (Would expect it to be better than the GY due to more aggressive tread, but without driving it in snow I have no comment)
2- Treadlife.
Would I reco the tire?
Yes, with the MPG caveat.........which would be the same for most other tires IMO.
Homer