Molded carpet pad for Dadge van?

From : exoticscales com

Q: the front wheels get the most drive. always! if not your rear bumber will out race the front down the road. on all 4 wheel drive vehicles the front diff will always be a little bit taller for that reason like 3.54 front 3.55 back. the front must always be boss. on awd vehicles the difference is absorbed through the viscous coupling. this is why your normal 4 x 4 cautions the use of 4wd on bare pavement. on those vehicles the tires must slip. that is why awd vehicles get slightly poorer fuel consumption over their counterparts. steve 2005 ram 1500 awd can anyone explain how this system works which wheels get the most power etc. thanks bob m .