City have again spent big money this summer with Yaya Toure, David Silva, Jerome Boateng and Aleksandar Kolarov all arriving at Eastlands.
However, Scholes still views current title-holders Chelsea as United’s main rival.
"Who will our biggest rivals for the title be? You have got to say Chelsea. And the rest... you just do not know.” Scholes said.
"City? We will have to see what happens there. They have bought so many players. Whether they can gel together remains to be seen.
"It is great for the city to have two top teams. It's a change from them being in the second division 10 years ago!
"There has always been big rivalry between us anyway, but even more so with the power they have got.
"Will their spending help to motivate us? Yes. The last thing we want is City above us. It has not happened while I have been here and hopefully it won't."
Scholes, entering his 17th season with the Old Trafford outfit, is also tipping Liverpool to have an improved season.
“Liverpool could be contenders. It just depends on how they start with a new manager.
"You always have to be wary of Liverpool. The season before last they were really close to giving us a major challenge.
"Last season, for whatever reason, it did not work out for them. It is much the same group of players, with Joe Cole added to it as well. I am sure they will be a good team this year round.”
United start their league campaign with a home game against promoted Newcastle United on August 16.
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