The suspension and the wheels are the principal parts of a car that impact traction. Modifying these two systems can improve handling in good and inclement weather, no matter what your budget is. Chains, sway bars, shock absorbers and springs all can impact the ability of the car to transfer power from the engine to the four fist-sized contact patches where the tires meet the road.
The tires on your car are the only parts of the vehicle in constant contact with the road. When it rains or snows, tires that are designed to channel water can improve grip by limiting hydroplaning. If you live in an area that receives frequent snow storms and need to be able to use your car, tire chains are another way to gain traction at low speeds. The metal surrounding the tires can help limit slides, but they can generally only be used at speeds of 25-30 mph.
Fewer snow and rain storms during the spring and summer months mean that it is time to use tires that have a finer tread than all-season or snow tires. It allows more of the tire to remain in contact with the ground.
Beyond the wheels, you can consider suspension modifications during warmer weather when it is easier to take the time to work on a car or send it to a repair shop. For example, the springs and shock absorbers that link each wheel to the chassis can be stiffened to reduce the amount of movement the car makes as it travels over various surfaces. A stiffer set will increase traction by keeping the tire more firmly in contact with the surface, but the ride may feel more bumpy. Another option is to install aftermarket anti-sway bars. They can add rigidity to either the front or rear pairs of wheels, preventing the body of the car from leaning during turns. A rear anti-sway bar will increase the traction of the inside rear wheel during hard turns, and can make a front-wheel-drive car less likely to skid in turns.
The parts that you modify or improve in your vehicle can help it to maintain traction during inclement weather or in spirited driving, but knowing vehicle dynamics can help as much as any equipment will. Race car drivers use a diagram called a friction or traction circle to gauge how fast they can turn their vehicles, but there are benefits for everyday car usage. A car that is accelerating or braking as much as possible is using the tires to their limits. You can see this if you imagine a car at a drag strip that only goes in a straight line. In normal driving, this means that the more you use the brake or gas pedal, the less you can turn the car to the left or right without the car beginning to lose traction. Steering gently can help improve traction during these conditions.
