I currently use Castrol GTD 15W-40 for both our Strada and Trooper. So far smooth naman takbo nila. Napansin ko lang with our Trooper, it used previously Rimula X and Petron Revx Trekker. Malakas kumain ng oil with the two API CH-4 oils. Pero sa Castrol wala halos oil oil consumption eh API CF-4 lang siya. With this I think ok ang Castrol pero try ko Mobil with the next oil change.