The Frenchman's comments follow those of Alonso's last teammate Felipe Massa this week, as the Brazilian tipped Alonso to be faster this year because he "combines talent with brains".
Grosjean, however, may also be well placed to comment, given that he too has been paired in F1 with both Alonso (2009) and more recently with Raikkonen at Lotus.
"Good luck to them!" he grinned to Brazil's Totalrace.
"They are two very strong personalities. It will be interesting," said Grosjean.
"Kimi is very much like Fernando in several respects. Both like to be number one, so we'll see what happens.
"If there is something I could learn from Kimi and Fernando it is that they never quit. Whenever they get into the car, they get 100 per cent from it, whether it is a good car, bad car, if it's dry, wet."
Meanwhile, the Finnish newspaper Turun Sanomat reports that Grosjean, 27, will no longer work with his manager Eric Boullier, after the former Lotus boss moved to McLaren.
The Lotus-linked management stable Gravity is now headed by Gerard Lopez, but correspondent Heikki Kulta cited sources in claiming Boullier's long-term successor will be appointed before the forthcoming Bahrain test.