* The vehicle's sticker (window sticker or build sheet): This will list the axle ratio.
* The driver's side doorjamb sticker: Sometimes this contains the axle ratio information.
* The owner's manual: This *might* list it, but it's not always included.
* The vehicle's title or registration: This is unlikely to specify the gear ratio.
* Physically inspecting the axle: The ratio is stamped on the differential housing (usually requires removing a cover plate). This is the most reliable method, but requires mechanical knowledge.
Common gear ratios for the 2009 Ram 1500 included:
* 3.21: Often found with larger engines and those aiming for better fuel economy.
* 3.55: A fairly common all-around ratio offering a balance between performance and fuel efficiency.
* 3.92: More common with V8s and for towing or off-road use.
* 4.10: Usually in heavy-duty configurations or those frequently towing heavy loads.
Without knowing the specific trim level and options of the truck, it's impossible to give a definitive answer.
