I had it made – everything was great, and then I screwed it up. I had power, I had fuel economy, the transmission did not hunt gears.
I accidentally found the magic sweet spot with the 6.4L HEMI Powered RAM Power Wagon. Lightweight 37″ All-Terrain tires on equally light aluminum wheels meant a low(er) rotating mass, and the square hard face of the tire had less rolling resistance. That paired with the thoroughly researched 5.13 differential gear ratios meant that the 7500lb brick could pull a surprisingly handsome 15-16mpg on the highway at 70MPH.
But then those wore out, and I replaced them with more aggressive Falken Wildpeak MT01 tires. Mud terrain tires are built heavier than All-Terrain tires, and their tall lugs catch wind more and create pockets of drag. They are also loud and have a higher rolling resistance, and more often than not are made of softer rubber compounds and do not last as long. I knew all these things before getting these MT’s and I still went through with it. All these factors working against me means 12.5mpg is all the vehicle can manage now.
Negatives aside, these Falken Wildpeak MT’s are wonderful tires, they work incredibly well Offroad, and offer fantastic traction. They self clean in the mud and are well mannered in the rain, and most of all – they are quiet. But, nothing can hold a candle to the superior road manors and drivability that a well designed All-Terrain tire offers, like the Falken Wildpeak AT3w.
Low rolling resistance of street oriented tires, lighter build construction and harder compounds allow AT’s to net performance gains that MT’s can’t match, and with modern computer aided designs, many AT’s offer traction superior to Mud Terrains of not that long ago. So while these MT tires offer superior Offroad characteristics, their abilities outpace the intentions of the vehicle.
The Power Wagon can be exposed to some pretty gnarly terrain, but it spends most of its time on the street. It’s locking front and rear differentials, as well its flexible suspension means that it can make make full use of all the friction afforded by its tires, and does not necessarily need MT’s to complete its goal. So, an MT, while effective, was an overreach for this truck and in the end has compromised its already limited fuel range, and was not an effective choice for the vehicle.
So when seeking out your next tire, make sure you are picking the appropriate tire for your vehicle, and weigh the consequences of the next size up, or a simple change in tread pattern.