The optimal gear ratio depends on how the engine fits the intended use of the boat. Courtesy Yamaha In every boat test we run, we include certain specs that we feel are valuable to our readers. Some ...

For part two of our series about transforming Jared Lehenbauer’s new-to-him ’01 Ford F-250 into a truck that’s better suited to his needs, we’re detailing how to select the correct gear ratio for two- ...

Most off-road vehicles have crawl ratios—extra gearing to increase forward thrust—between 30 and about 100. But the Mercedes Unimog, with its "Super Crawler" gear, has an absurd crawl ratio over 3000.

Vehicle speed (mph), engine speed (rpm), tire diameter (inches), trans gear ratio, and rear axle gear ratio are all interrelated. If you know four out of five of these values, you can determine what ...

Vehicle speed (mph), engine speed (rpm), tire diameter (inches), trans gear ratio, and rear axle gear ratio are all interrelated. If you know four out of five of these values, you can determine what ...