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Fuel and Gas Saving Tips - Conservation Of Energy

35 Fuel Economy Tricks From Tractor-Trailers

Photography by Courtesy Of Michelin, Ford, International, Jason Thompson

Hard times give charlatans offering snake oil easy prey. On the bright side, absolutely real solutions are forged from the stress and heat radiating from tough situations. Diesel Power jumped into the swamp of fuel efficiency and sifted the kernels from the chaff. The conservation of energy is an idea that, once mastered, is basically an mpg truth detector. Diesel fuel has a potential energy between 128,700-140,000 British thermal units (Btu). One Btu is the amount of energy needed to heat 1 pound of water 1 degree F. There are an infinite number of things you can do in order to get the most from this finite number. The most efficient heavy-duty diesel engines only use 51,480 Btu per gallon. This article pulls much information from the more advanced world (at least when it comes to the conservation of energy) of heavy-duty diesel technology. Let's apply tractor-trailer ideas to the realm of consumer diesels.

Fuel Economy Tips From Tractor TrailersInternational creates 436,000 diesel engines a year. Check out what it recommends to improve fuel economy. Remember, the first 22 tips are tractor-trailer specific, but with a little creativity they can be modified to our core segment. Here is a compiled list of fuel saving ideas from a profitable medium/heavy truck manufacturer:

1. A worn tire is about 7% more efficient than a new tire. The break-in period for tires is between 35,000 and 50,000 miles.

2. Every 10 psi that a tire is underinflated reduces fuel economy by 1%.

3. Tires make the biggest difference in mpg below 50 mph. Aerodynamics is the most important factor over 50 mph.


5. Above 55 mph, each 1-mph increase in vehicle speed decreases fuel economy by 0.1 mpg.

6. The most efficient drivers get about 30% better fuel economy than the least efficient drivers.

7. Aerodynamic treatments can reduce the horsepower required to move the truck by 30 to 35 hp.

8. Every truck does not have to be fitted with all the aerodynamic features available. For example, if the vehicle is only used for local deliveries, it does need air dams designed for highway use.

9. Every 2% reduction in aerodynamic drag results in approximately 1% improvement in fuel economy.

10 The rpm level where the engine cruises can provide critical fine-tuning of fuel economy. To do this, you can spec the axle gearing so that the engine runs at its torque peak.

11. All oil thickens at low temperatures, causing increased fuel consumption. Synthetic oil is less affected by temperature, thus making it more fuel-efficient.

12. Tires flex more at higher speeds. This leads to more friction, higher tire temperatures, and reduced fuel economy.

13. Rolling resistance results from the internal friction of a tire as it deflects (flexes) during motion. Energy spent generating heat in the tires is energy that does not contribute to moving the vehicle. Cooler running tires are more fuel-efficient than tires that run hotter.

14. Air conditioner power demands are relatively small compared to the cooling fan, but every little bit helps so drive with the A/C off.

DP Diesel Power Note:
Although lighter duty diesel engines don't have air brakes, they do have A/C compressors and other accessories, which should be inspected to see if they spin freely.

15. Exceeding the recommended engine oil levels can lead to significant oil churning/spin losses, resulting in reduced engine efficiency and mpg.

16. It takes between 10 and 70 hp to drive the cooling fan, so cooling system maintenance can have a significant effect on fuel economy.

DP Diesel Power Note:
Replacing the stock clutch fan with a Flex-a-lite twin electric fan setup is said to recover 27 hp and increase fuel mileage by 6%.

17. A tire that is misaligned only 1/4-degree from straight will try and travel 10-15 feet sideways for each mile, resulting in lower fuel economy.

Diesel Power