i would second your comment regarding the drain interval of havoline .. as opposed to 800 recomended by hathora mechanics .. i have used it alot and always found it effective till 1200 km and at certain times i have used it for 2k kms..
but in cases of emergency i have frequently used it till 1500-1600 km .. though there was a decrease in its effectiveness after 1200 but that decrease was more drastic after 14-1500 kms ..
and i have always been changing oil at 1200 kms .. nowadays i am using castrol 20w50 and its much better then havoline.. though initialy when i switched from havoline to castrol it was behaivng worst in clutch issues .. but after one or two drains now its working as it should be ..