Although this is an old died out thread but I thought I may place a comment that some one searching like me may find useful.
Yesterdat, while driving back from Hyderabad to Karachi, I pushed it to 90km/h in 4th gear and then in 5th gear, I pushed it to 140km/h. RPM was 4000 and accelerator was half way down. It drove smoothly at this speed with no jerks.
I hope by 5000 RMP, you may easily reach 160km/h