RE: -=OFFICIAL HPI FIRESTORM THREAD=-
Bushhiker - I havn't changed the diff oil in my FS but put 7000 in my savage and MT2. This is a good weight, it limits differential slip and stops 'diff spinning'. It will increase the chance of the engines power going to the outer wheel instead of the inside wheel in a tight turn under power. With lower weight oil the wheel on the inside of the turn gets all the power when it lifts off the ground and and transfers the weight/force of the truck to the outer wheel that does not spin.