
"Axle", which is the bearing connecting two wheels, is also called "wheel axle". Each pair (left and right) of tires is connected by an "axle", and the so-called number of axles refers to the number of wheel axles. Below is a related introduction to axles: Introduction to Car Axles: Axles are mainly used in cargo trucks, military vehicles, special vehicles, or large buses. The axle is connected to the frame (or load-bearing body) through the suspension, with wheels installed at both ends. According to the number of axles, they can be divided into: single axle, double axle, front four rear four, front four rear eight. More axles include semi-trailers, two-axle trailers with three axles, and three-axle trailers with three axles. Ordinary family cars generally use a single axle. Highway transport vehicles with a total mass of less than 19t and vehicles whose axle load is not restricted by roads or bridges, such as mining dump trucks, use a simple and low-cost two-axle solution. Highway transport vehicles with a total mass of 19-26t adopt a three-axle form. Function of Axles: The function of the axle is to bear the load of the car and maintain the normal driving of the car on the road.

The number of axles on a car simply refers to the count of wheel-mounted axles on the vehicle. When you look at regular passenger cars on the road, they typically have two axles: one at the front carrying two front wheels, and one at the rear with two rear wheels. Large trucks are different, some having three or even four axles. This design helps distribute weight and carry more cargo. For example, a six-axle heavy-duty truck can easily haul dozens of tons. More axles mean a longer vehicle and a larger turning radius, which becomes especially noticeable when maneuvering in parking lots. I've seen some special-purpose vehicles at construction sites deliberately add axles to adapt to muddy terrain, with each axle equipped with a differential lock, making it easier to escape if stuck. Choosing the number of axles depends on the intended use—ordinary family cars really don’t need a multi-axle design.

Seasoned truckers know that the number of axles determines the load capacity. My three-axle truck can haul ten more tons than a two-axle one, with each axle staying within the weight limit. Highway toll stations charge directly by the number of axles—more axles mean higher fees. Repair shops often see more axle failures in multi-axle vehicles due to greater weight and faster wear. Off-road, the number of axles affects traction: two-axle vehicles struggle with cross-axle slippage, while three-axle military trucks climb slopes more steadily. When buying, note that axle count impacts vehicle length and turning radius—parking in underground garages becomes a real skill test.

Most private cars have a two-axle design, with the front axle responsible for steering and the rear axle for driving. Occasionally, SUVs can be seen with three axles, where the last axle assists in enhancing load capacity. Those who have driven long-wheelbase vehicles know that cars with more axles handle speed bumps more smoothly. However, for everyday city driving, fewer axles are more convenient, making parking easier and handling more agile. The difference is particularly noticeable on highways, where multi-axle large trucks remain stable even at 120 km/h. My neighbor, who bought a pickup for hauling, always complained that two axles weren't enough and later installed a retractable third axle.


