The lifespan of a rebuilt engine can vary significantly, depending largely on the quality of the rebuild, the materials used, and how the engine is maintained thereafter. On average, a properly rebuilt engine can last as long as a new one—often 150,000 to 200,000 miles, sometimes more. Key factors that determine its longevity include the skill of the mechanic, the replacement of wearable parts (like bearings and seals) with high-quality components, and the thoroughness of the engine cleaning and machining processes during the rebuild. Regular maintenance, such as timely oil changes and keeping the cooling system in good order, is crucial to maximizing the life of a rebuilt engine. Moreover, the engine’s operating conditions—whether it's used for regular commuting or subjected to more strenuous conditions like towing or racing—can also significantly impact its lifespan. Hence, a rebuilt engine, when done correctly and maintained properly, can serve as a cost-effective and reliable alternative to purchasing a new engine.

The charging needs of a hybrid car vary depending on the type. For plug-in hybrids. charging is necessary due to their larger battery packs that can be recharged externally at home or public stations. After driving a certain distance on electricity. the gasoline engine takes over. On the other hand. standard hybrids do not require external charging as their batteries are replenished through regenerative braking and the internal combustion engine. They also offer various driving modes to prioritize fuel efficiency or power. Ultimately. whether your hybrid needs to be charged or not is determined by its classification as a plug-in or regular model.

The lifespan of motorbike tyres can vary significantly based on several factors, including tyre composition (soft, medium, or hard compound), riding style (aggressive vs. conservative), road conditions, and maintenance practices. Generally, motorcycle tyres can last between 3,000 to 15,000 miles. Soft compound tyres, which offer more grip, may wear out faster, especially if used aggressively or on poor road surfaces. Hard compound tyres provide less grip but typically have a longer life. Regular checks for tyre pressure, tread depth, and signs of wear or damage can help maximize tyre lifespan. Moreover, storing the bike properly and avoiding exposure to extreme temperatures or sunlight can also prolong tyre life. Ultimately, adhering to the manufacturer's recommendations and observing your riding conditions and habits will be key in determining how long your tyres will last.

Nitrogen and air can both be used to inflate car tyres, but they offer different benefits. Here are some points of comparison:

1. Purity: Nitrogen is a pure gas that doesn't contain any moisture, while air contains some water vapor. This moisture can have some potential impacts on your tyres and tyre pressure.

2. Pressure Stability: Nitrogen is less likely to migrate through tyre rubber than compressed air. This means that your tyre pressure will remain stable longer when inflated with nitrogen. On the other hand, tyres filled with air can lose about 1.5 PSI per month.

3. Temperature Resistance: Nitrogen is a dry gas, so tyres filled with nitrogen are less likely to experience pressure changes due to variations in temperature. With air, the presence of moisture can lead to significant fluctuations in tyre pressure as the temperature changes.

4. Corrosion: Air, because it contains oxygen and moisture, can cause oxidation and corrosion to the metal parts of the tyre. Nitrogen, being a dry and oxygen-free gas, reduces this risk.

5. Cost and Availability: Air is obviously much easier to find. Filling your tyres with air is typically free, while nitrogen services can come at a cost.

6. Environmental Impact: Nitrogen inflation may be more eco-friendly. Tyres filled with nitrogen maintain their optimal pressure longer than those filled with air, which means your vehicle can achieve maximum fuel efficiency.

In conclusion, nitrogen can be beneficial for maintaining consistent tyre pressure and possibly prolonging tyre life, but using air in tyres is more convenient and cost-effective. For most everyday drivers, regularly checking and maintaining tyre pressure, regardless of the inflation gas, is sufficient to optimize tyre performance and longevity.