Sundowns are third on the log with 31 points from 15 matches - three points behind leaders Bidvest Wits with three games in hand.
With Downs and second-placed Orlando Pirates still competing in the CAF Champions League, Mosimane believes that will take a lot out of their gas tanks.
"I don't want to focus on people who've got more points than us," Mosimane said.
"Let's take it one step at a time because this thing is going to go for long. I don't know who will sustain it.
"Now it is still okay because we still have resources a little bit, and the fuel is still there.
"But I'm looking at the gauge and seeing who will last longer."
Mosimane, however, believes his side's experience of winning the league will come in handy again.
"But we have Hlompho Kekana and Tiyani Mabunda, who know how to manage the game well.
"We have experience to manage the game. We have the likes of Anele Ngongca, who played Champions League football in Europe."
Downs will resume their Absa Premiership title defence against relegation-threatened AmaZulu at Loftus Versfeld tonight (19h30).