What is the best gear ratio for highway driving?

The best gear ratio for highway driving typically falls between 3.08 and 3.73 for most vehicles, depending on the engine size and vehicle type. A lower gear ratio, like 3.08, allows for better fuel economy and quieter operation at higher speeds, while a slightly higher ratio might provide more power for hills or acceleration. Ultimately, the optimal ratio balances fuel efficiency and performance, considering the vehicle's specific design and intended use.