Yes, because Grosjean finish his race sims by a long run with hard tyres, while Alonso have a 4 stopper strategies.
It's seems Ferrari will be very agressive with the tyres this year, so we will see many pit stop for them. For me, with the F150 they want to stay on track longer with less pit stop than RB and Mclaren ( this cost a Massa victory at China ), and with F2012, they will do quali lap at each stint, but they will do more pit stop.
16:15 Stint one was nine laps on mediums, consistently in 1m30s with a few 1m31s.
Stint two was eight laps on softs, starting in low 1m29s, then going up to mid 1m30s before a single 1m32s.
Stint three was 12 laps on softs, going up from low 1m28s to mid 1m31s.
Stint four was 14 laps on mediums, going from mid 1m27s to mid 1m29s.
Stint five was 14 laps on mediums again, from mid 1m24s to high 1m26s.
Ferrari use USED tyres, and Lotus new tyres...