The 30-year-old is in phenomenal form this year after winning the first two legs of the series in Cape Town and Port Elizabeth.
For the Port Elizabeth victory in May, Phalula ran the fastest 10km in South Africa in five years after clocking 32 minutes and 27 seconds.
The runner, now coached by the renowned Michael "Sponge" Seme, said she was not under pressure because she has done her homework.
"I'm ready to win in Durban, but it's not going to be easy. We have all the big guns coming and they also want to do well to get more points to win the car.
"For me the biggest challenge will come from my twin sister Lebogang, who is in great form after returning from maternity leave.
"I want to win the grand prix and see myself driving that car," said Phalula.
Lebo leads the field with 60 points, 26 ahead of Mapaseka Makhanya, who won the grand prix last year.
Meanwhile, the Pick 'n Pay Central Gauteng Athletics 5km and 2.5km development road races will take place in Westonaria tomorrow.