Frequently Asked Questions About Freightliner Century 112/120 Diesel Fuel Tanks

What size fuel tanks are available for my Freightliner Century 112/120, and how do I determine the correct capacity?

Fuel tanks for the Century 112/120 typically range from 50 to 150 gallons, with 100-gallon and 120-gallon being the most common sizes. To determine your current tank capacity, check the data plate on your existing tank or measure the tank dimensions (length x height x width in inches, then divide by 231 for gallons). Most Century models from 1996-2011 can accommodate dual 100-gallon setups or single 120-gallon configurations, depending on your frame rail spacing and wheelbase.

Will these fuel tanks fit my specific year Century model, and are there differences between Century Class and Columbia tanks?

These tanks are designed specifically for Century 112/120 models from 1996-2011. While Century Class and Columbia models share similar frame dimensions, the mounting brackets and strap configurations differ. Century 112/120 tanks use a 23-inch strap spacing with specific bracket holes at 26 inches and 38 inches from the front. Always verify your truck's VIN and model year before ordering, as pre-2000 models may require different mounting hardware.

What material options are available, and which is best for my application?

You can choose between aluminum and steel tanks. Aluminum tanks (typically 0.125-inch thick) weigh about 50% less than steel, resist corrosion better, and are ideal for weight-conscious operations. Steel tanks (14-gauge) cost less upfront and handle impact better but require regular inspection for rust. For trucks operating in northern climates with road salt exposure, aluminum is strongly recommended despite the higher initial cost.

Can I install these tanks myself, and what special tools or modifications are required?

Installation typically takes 3-4 hours per tank for experienced mechanics. You'll need basic hand tools, a floor jack or transmission jack to support the tank, and potentially a drill for new mounting holes. Most installations are bolt-on, but some applications require relocating crossmembers or modifying existing brackets. The fuel return line, sending unit, and draw tube from your old tank can usually be transferred. Professional installation is recommended if you need to relocate DEF tanks or modify emission components.

Do these tanks come with mounting straps, brackets, and sending units?

Most replacement tanks come as bare units without mounting hardware or sending units. You'll need to purchase mounting straps (typically $45-65 per set), brackets, and transfer your existing sending unit and fuel pickup assembly. Some suppliers offer complete kits that include new straps and brackets, which is recommended if your current hardware shows signs of corrosion or fatigue. Sending units are sold separately and should be replaced if your fuel gauge reads inaccurately.