Effects of Mismatched Tires on Drivetrains

March 14, 2016

Tires and their condition play a major role in the longevity of a vehicle. In this blog post, we will focus on the effects mismatched tires have on a vehicles drivetrain.

The vehicles drivetrain includes:

  • the engine
  • the transmission
  • the transfer case (if four-wheel or all-wheel drive)
  • the drive axles
  • bearings
  • vehicle frame
Two-Wheel Drive

Mismatched tire sizes on a two-wheel drive vehicle will affect various drivetrain components and could cause harm. One area in particular is the differential assembly. The differential assembly allows different rates of speed of the tires and wheels from side-to-side during turns, and still allows the vehicle to be propelled.

When your tires are the same size, the differential has an easy life as the internal gears do not do any work unless there is a difference in speed, such as turning. With two different size tires there is a difference in speed even going straight down the road. This will over-work the differential and harm it very quickly.

Four-Wheel/All-Wheel Drive

The same rule applies for four-wheel and all-wheel drive vehicles. All four tires need to be of the same size, brand and tread depth. All-wheel drive vehicles drive all four tires at all times. Four-wheel drive can be selected by the driver or automatically applied when needed in four-wheel drive vehicles. These vehicles may have a center differential to differentiate speed differences from front to rear and conventional differentials for side-to-side differential action, making universal tire size important.

By: Brett Ritchey