"Anyone in the top four can win it - maybe Scott McLaughlin and Will Davison as well.
"There are so many strengths and weaknesses in the top four - winning races, versus mistakes, versus pressures, versus being one guy against three from the other team.
"December will make for an interesting story."
Winterbottom was criticized in some quarters after stating a couple of rounds ago that the two Red Bull Racing drivers will need to race each other at some point and that could test their relationship. Critics pointed out that Whincup and Lowndes had essentially been in a similar position for the best part of a decade without many dramas between the pair but Winterbottom says Van Gisbergen is a different proposition for Whincup.
"The difference is that Shane can qualify very strongly. In previous years it was 20 qualifying positions for Whincup compared to Lowndes' five. Seventy five percent of the time or more he was in front of Craig on the track.
"When you do stuff like that you get priority and you get to pit when you want.
"If you are pretty even at qualifying you are swapping positions a lot more.
"Now, if you have two guys going into Bathurst or Gold Coast and they are only separated by 100 points or less, they have to race each other on track to get to the pit stop first. If a safety car comes out with 25 laps to go at Bathurst and you are the second car in the race you could go from second to 15th so there are massive consequences now when you have two very good guys battling it out.
"They may not be ramming into each other and stuff like that but you are fighting each other for pit priority and it can win or lose some of the biggest races we go to.
"When you are sitting second to a teammate and you know that situation can come up - there is a point where you don't just sit behind and lose the biggest race of the year."
This weekend is the last sprint round before the series moves to the three-event endurance schedule including the Sandown 500, Bathurst 1000 and Gold Coast events, where leading drivers are paired with non-championship teammates in shared drives.