Reader Question: Should I Buy a Gasoline or Diesel HD Truck to Tow 12,000 lbs?

2015 april and may diesel and gasoline fuel prices in Colorado rocky mountain region

Jaime A.Z. asks TFLtruck:

I have a dilemma. I am looking for a truck to tow a 12,000 lb 5th-wheel and dealers are pushing me to go with a diesel. The additional cost is $8,000+. What are the pros and cons of gas vs diesel?

This is a great question and one that we get often.

Gasoline HD Truck Pros:

  • Lower initial purchase price: Yes, a gasoline-powered heavy duty truck has a significant initial purchase price advantage. The extra cost of a diesel can vary between $8,000 – $11,000, depending on brand and configuration. This is a large obstacle to overcome. The diesel payback occurs after a lot of miles due to better towing efficiency.
  • More Payload Capacity: A turbo-diesel engine and a corresponding transmission can weigh 600-800 lbs more than their gasoline counterparts. As such, the payload rating on a gasoline-powered truck can be significantly more than a diesel. The more payload capacity you have, the more flexibility you have to carry people, cargo, and trailer tongue weight.
  • Lower Maintenance Costs: Diesel motors and corresponding transmissions are built to handle high pressures and heavy abuse. However, oil changes and other services are more costly.

Check out the Silverado HD towing up the Ike Gauntlet here:

Diesel HD Truck Pros:

  • More Power: This is not just what you see on the specifications sheet. It’s the power you can feel while in the driver’s seat. Diesel motors have gobs of low-end torque and can pull heavy loads up extreme grades with confidence. We know this from our Ike Gauntlet testing.
  • More Efficiency: Heavy trucks with turbo-diesel engines are significantly more efficient than gasoline counterparts when running empty and loaded. The question you have to answer is: can the increased efficiency of a diesel make up for the added initial purchase price? The typical answer is that it may take around 200,000 miles to recoup the initial cost difference if you consider fuel costs alone, and remember, fuel prices are always changing… making the break-even analysis difficult to nail down.
  • More Towing Capacity: Diesel-powered trucks are generally rated higher on the maximum towing capacity. However, don’t lose sight of the payload capacity specifications. Knowing the tongue weight of your trailer is very important.

Check out this comparison of the HD diesel offerings from the big 3 here:

The bottom line is – it’s better to choose a diesel-powered HD truck if you plan to tow frequently and put at least 200,000 miles on the truck. If you are an occasional tower and will not put a lot of miles on the truck, then a gasoline-powered HD truck is a better choice.

Jamie, the 12,000 lbs 5th-wheel trailer that you have is not heavy enough to justify a diesel truck. However, you should answer the questions about how often you will tow and how many miles will be on the odometer, before you pull the trigger on a new truck.

Andre Smirnov is an Automotive Enthusiast, Producer, Reviewer, Videographer, Writer, Software Engineer, Husband, Father, and Friend.