Windshield wipers are the lowest-cost safety maintenance item on a car and the most commonly deferred beyond their useful service life. A wiper blade that streaks, skips, or leaves areas of the windshield uncleared reduces visibility in rain to a level that slows reaction time in ways that have been documented in wet weather accident statistics. The replacement cost is $20 to $50 for a complete set of wiper blades. The installation takes five minutes with no tools. The safety return on this investment is among the highest available in automotive maintenance.

Tires are the only point of contact between a vehicle and the road. Every input — braking, steering, acceleration — is transmitted through four contact patches, each approximately the size of a human hand. The condition of those patches determines the vehicle’s actual capability regardless of what the chassis, the brakes, or the electronics are capable of achieving. A car with excellent brakes and worn tires will stop in a longer distance than a car with mediocre brakes and excellent tires. Physics does not allow the alternative.

Brake fluid is hygroscopic. It absorbs moisture from the atmosphere through the brake system’s seals and reservoir cap over time. The moisture absorption is unavoidable regardless of driving habits or climate. What changes with moisture content is the fluid’s boiling point — as the water content increases, the boiling point decreases, and when brake fluid boils it converts from liquid to gas, and gas is compressible in a way that brake fluid is not.