Fuel Efficiency Comparison: Big Trucks vs. Cars

When considering the fuel efficiency of vehicles, the comparison between large trucks and cars often leads to intriguing discussions. Many mistakenly believe that big trucks consume more fuel than cars, mainly because of their sheer size. However, as experience and empirical data from professional drivers and mechanics suggest, it's not just about the engine size or the weight. This article delves into the nuances of fuel consumption for different types of vehicles.

Personal Experiences

For instance, Mike Heaton, an experienced truck driver, shares his insights. Mike's journey with different types of trucks and cars highlights the complexities of fuel efficiency. He owned a large Kenworth with an 8-cylinder Caterpillar engine, which achieved about 6 miles per gallon (mpg) at 80,000 pounds and 75 mph. After retiring, he switched to a Ford F350 diesel with a 6.7-liter engine, which still achieved 6-8 mpg at 75 mph and 26,000 pounds. Although the truck seemed to use more fuel, it carried significantly more weight, resulting in better fuel efficiency per ton.

Mike's previous truck, a Scania R series, had a peak load of 44 tons fully loaded or 18 tons with an empty 40-foot container. His average fuel economy was around 9 mpg, despite driving on various road conditions. In contrast, his current vehicle, a VW Jetta 2-liter TDI, achieved an impressive 60 mpg under mixed driving conditions.

Contemporary Insights

As Mike points out, the fuel efficiency of large trucks has improved significantly from his experience in the 1960s to the present day. Contemporary large trucks can now achieve fuel efficiencies ranging from 2 to 10 mpg, depending on the load and driving conditions. A big rig used in stop-and-go traffic in the city might get as low as 3 mpg, whereas the same rig used on a freeway might achieve up to 10 mpg. This range can be surprising to many car owners, who often underestimate the efficiency of large trucks.

Economic and Environmental Considerations

While big trucks consume more fuel per mile, their efficiency per ton of cargo is often higher. As Mike also mentioned, hauling eight cars that get 14 mpg can be done more efficiently on a truck that gets 7 mpg. This is because you can transport a much larger payload in a single trip, reducing the need for multiple smaller vehicles and their drivers. Additionally, the fuel consumption per mile is lower on the highway, making long-distance travel more efficient.

For instance, Mike's current business involves converting large trucks into smaller, more efficient SUVs. After conversion and carrying approximately 40% of the gross weight, the re-geared and ungoverned truck achieves about 11 mpg. This efficiency is even more pronounced when considering the haulage of heavy loads. A large truck that gets 7 to 8 mpg can transport 15 tons of gravel, while a smaller truck that gets 12 to 13 mpg can only transport 2 tons. Clearly, the larger truck is far more economical in terms of fuel consumption for the load it carries.

Conclusion

While big trucks may appear to be less fuel-efficient compared to cars, it's essential to consider the type of load and driving conditions. The fuel consumption per ton of cargo is often higher for cars, especially in urban environments. In contrast, large trucks, despite their higher fuel consumption, can transport significant loads more efficiently, making them a more environmentally and economically viable option for long-distance and heavy load haulage.