Peterbilt Fuel Tanks

Frequently Asked Questions About Peterbilt Fuel Tanks

What size fuel tanks are compatible with my Peterbilt model?

Fuel tank compatibility depends on your specific Peterbilt model and year. Most common sizes range from 50 to 150 gallons, with 100-gallon and 120-gallon tanks being the most popular. For 379, 389, and 388 models (2000-present), you can typically fit tanks from 23" to 26" in diameter. For 567, 579, and 587 models, check your frame rail spacing as these newer models may have different mounting configurations. Always verify your truck's specific measurements and mounting bracket locations before ordering.

Are aluminum or steel fuel tanks better for my Peterbilt?

Both materials have distinct advantages. Aluminum tanks are 30-40% lighter than steel, improving fuel economy and payload capacity. They resist corrosion better and typically last 15-20 years with proper maintenance. Steel tanks are more affordable upfront (usually 20-30% less expensive) and are easier to repair if damaged. However, they require regular inspection for rust and typically need replacement every 10-12 years. Most owner-operators prefer aluminum for long-haul applications, while steel remains popular for local and vocational trucks.

What mounting hardware do I need to install replacement fuel tanks?

A complete fuel tank installation requires tank straps (usually 2-3 per tank), mounting brackets specific to your frame width, rubber isolation strips to prevent metal-on-metal contact, and grade 8 bolts with lock washers. You'll also need fuel line fittings (typically 5/8" or 3/4"), a sending unit gasket, and new fuel cap. Many installations also require crossover line kits for dual tank setups. Budget 2-4 hours for installation per tank, depending on whether you're replacing existing tanks or adding new ones.

Can I upgrade from a single to dual fuel tank setup on my Peterbilt?

Yes, most Peterbilt models can be upgraded to dual tanks, but it requires additional components. You'll need a second tank with appropriate capacity, Y-valve or electric switching valve, crossover fuel lines, additional mounting hardware, and possibly a new dash switch for electric systems. The total cost typically runs $800-$1,500 in parts alone. Ensure your frame has adequate space and mounting points on both sides. Models with air ride suspensions may have clearance limitations that restrict tank size options.

What's the difference between round and D-shaped fuel tanks?

Round tanks are the traditional choice, offering maximum capacity for their size and easier installation with standard strap mounts. They typically provide 10-15% more fuel capacity than D-tanks of similar dimensions. D-shaped (or rectangular) tanks mount flush against the frame rail, providing better ground clearance and a cleaner appearance. They're ideal for trucks with limited space or those requiring maximum ground clearance for off-road applications. D-tanks also offer better protection from road debris but cost approximately 15-20% more than equivalent round tanks.