Final answer:
When driving in heavy snow or fog, use your low-beam headlights to improve visibility. Cars with superconducting wires wouldn't experience headlight dimming on engine start, except for effects from the battery's internal resistance. Weather conditions and temperature can affect car performance and control, but the gasoline gauge reading remains consistent because it measures volume.
Step-by-step explanation:
If you must drive during heavy snow or fog, you should indeed use your low-beam headlights. Using low-beam headlights helps in reducing the glare that can be reflected back by the snowflakes or fog droplets, improving visibility somewhat. In contrast, high-beam headlights can cause a reflection that makes it even harder to see.
In terms of general car maintenance and physics, if wires in your car were made of superconductors, your headlights would not dim when the car's engine starts. This is because superconductors have no electrical resistance, which means the full power of the battery could be used without any voltage drop across the wires. However, it's important to also consider the battery's internal resistance, which could still cause some dimming depending on the condition and quality of the battery.
During the winter, cars may exhibit different behavior. For example, a cold winter can affect fuel efficiency as fuels like gasoline are denser at lower temperatures; however, modern cars are designed to adjust for temperature changes. Also, if a light rain occurs, the mixture of oil and gasoline on the road can make it slippery and more challenging to control the car. A heavy rain can potentially wash away the oil and gasoline, thus improving traction, but it also can cause hydroplaning if water pools on the road.
The reading on a gasoline gauge is typically not affected directly by temperature as it measures volume rather than the density of the gasoline. Still, temperature changes can affect fuel density and thus how much energy you actually have in your tank.