Vostro 5460, i3-3120M + HD 4000@RM1,549[1.54kg], 4GB, 500GB(5400rpm), Ubuntu 12.04, 3 cell; W8SL@RM1,749
Vostro 5460, i3-3120M + Nvidia GT630M@RM1949[1.54kg], 4GB, 500GB(5400rpm), W8SL, 3 cell
Vostro 5460, i5-3230M +Nvidia GT630M@RM1899[1.54kg], 4GB, 500GB(5400rpm), Ubuntu 12.04, 3 cell; W8SL@RM2099
Vostro 5460, i5-3337U + Nvidia GT630M + (32GB mSATA SSD + 500GB(5400rpm))@RM2199[1.54kg], 4GB, W8SL, 3 cell
If you obsolutely need light weight, and still has reasonable power to run some CAD, math, software, then go for the i5-3230M spec.
Since you did not mention your budget, I suppose it is around RM2k?
For engineering course, if you ever need to run some apps that need CPU work load, try to go for laptop with i7 quad core.
Try to look for this Lenovo, more or less the cheapest laptop with i7 quad core in Malaysia now.
Ideapad Z580, i7-3612QM + Nvidia GT640M@RM2299, 4GB, 500GB(5400rpm), freeDOS, white
Ideapad Z580, i7-3612QM + Nvidia GT640M@RM2499, 4GB, 500GB(5400rpm), W7HB, white
Prices are RSP, negotiable.