* Make and Model of the Vehicle: Different manufacturers tune their 3.9L engines differently. A 3.9L engine from a Jeep will likely have different horsepower than a 3.9L engine from a different manufacturer.
* Year of Manufacture: Engine technology improves over time, leading to increases in horsepower for similar displacement engines.
* Modifications: Aftermarket modifications (like upgraded intake, exhaust, or engine management) can significantly increase horsepower.
To find the horsepower of a specific 3.9L engine, you need to specify the make, model, and year of the vehicle it's in. Then, you can consult a reliable source like the vehicle's owner's manual, a repair manual, or an automotive specifications website.
