Driver MPG Tips

MANAGING YOUR MILE PER GALLON

Equipment

Shift Optimization
  • Today's modern engines run better at lower rpm. Shifting should be done as soon as engine speed is high enough to allow you to move to the next gear.
  • Constant operation below 1300 rpm significantly improves fuel economy.
  • Peak rpm range is 1200 to 1500. Torque is higher at lower rpm and is more effective at pulling than horse power.
Tire Tread and Brand
  • Below 50 mph, tires make the biggest difference in driving mpg.
  • Half tread (worn) tires are approx 6% better on mpg than full tread (new) tires.
  • Ribbed tires are 2-4% better on fuel economy than lugged tires.
  • Every 10 psi under 100 that a truck's tires are under-inflated reduces fuel economy by 1%.
  • Fuel efficient tire brands can improve fuel efficiency by as much as .5 mpg.
  • CRE has found Michelin 275-80R-22.5 XDA energy for the Drives, and XZA3 for the steers are the most fuel efficient tires.
  • Tire condition and inflation is just as important on trailer tires as it is on tractor tires.
Transmission/Gearing
  • An engine geared to run 1450 rpm at 65 mph gets approx 4% better mpg than one geared to run 1600 rpm at 65 mph.
  • The optimal transmission gearing is 9-speed.
Exhaust Regeneration
  • Over the road regeneration uses approx 1 gallon of fuel, while parked regeneration uses approx 3 gallons of fuel.
  • When the dash light indicates a regeneration is needed while the truck is idling, Drivers should try to change duty status if possible so they're on the road when regeneration occurs.
  • Bio-diesel fuels will increase the number of regenerations required. Bio-diesel also generates less power and offers lower mpg.

Proper Driving Practices

Idle
  • Engines use up to one full gallon of fuel per hour while idling.
  • At 70% idle, a trucks overall fuel economy is reduced by almost one fifth, or approx one full mpg.
  • Modern engines do not require warm up periods. You can drive up to 70% throttle as soon as oil pressure is up. Drivers should shut off the truck when not in the cab.
  • Modern engines do not require long cool down periods. A 3 minute idle after stopping is sufficient to cool down the engine prior to shut off. Drivers should shut off the truck when not in the cab.
  • Bunk heaters are provided to eliminate the need for idling when outside air temperature is between 20 and 70 degrees.
  • If idling up is necessary for air conditioning or for extended idle, you should not exceed 900 RPM.
Smooth Acceleration and Braking
  • Suggestions for smooth operation include anticipating changes in traffic and road conditions, avoid abrupt stops or rapid changes in vehicle speed, and minimize use of service brakes by planning ahead.
  • Braking not only costs fuel economy because you're losing momentum, but also because you're activating an accessory that draws power -- the air compressor.
Driver Stops
  • Each stop costs approx one third of a gallon to return to speed.
  • Drivers should consolidate stops for food, fuel, showers, maintenance, pre-trips, and personal needs to reduce fuel expense.
Top Gear Cruising
  • One gear down decreases mpg by approx 16% due to gear mesh effect.
  • A 20% difference in time spent in top gear could result in as much as a 4% difference in fuel economy.
Out Of Route
  • Stay on route. Each out of route miles costs $.73 in fuel alone at $4.00 per gallon.
Preventative Maintenance
  • Ensure all regularly scheduled maintenance services are completed. Poor fuel economy could be equipment related.
  • Report any problems to maintenance immediately.