Measuring techniques

Your best source of information about actual fuel economy is you, the driver. You must gather information as accurately and consistently as possible. Fuel expense, frequency of fill-ups or fuel gauge readings are NOT accurate as a measure of fuel economy. We do not recommend taking fuel economy measurements during the first 1,000 miles (1,600 km) of driving (engine break-in period). You will get a more accurate measurement after 2,000 miles–3,000 miles (3,000 km–5,000 km).

Filling the tank

The advertised fuel capacity of the fuel tank on your vehicle is equal to the rated refill capacity of the fuel tank as listed in the Maintenance product specifications and capacities section of this chapter.

The advertised capacity is the amount of the indicated capacity and the empty reserve combined. Indicated capacity is the difference in the amount of fuel in a full tank and a tank when the fuel gauge indicates empty. Empty reserve is the small amount of fuel remaining in the fuel tank after the fuel gauge indicates empty.

The amount of usable fuel in the empty reserve varies and should not be relied upon to increase driving range. When refueling your vehicle after the fuel gauge indicates empty, you might not be able to refuel the full amount of the advertised capacity of the fuel tank due to the empty reserve still present in the tank.

For consistent results when filling the fuel tank:

• Turn the engine/ignition switch to the off position prior to refueling, an error in the reading will result if the engine is left running.
• Use the same filling rate setting (low — medium — high) each time the tank is filled.
• Allow no more than two automatic click-offs when filling.
• Always use fuel with the recommended octane rating.
• Use a known quality gasoline, preferably a national brand.
• Have the vehicle loading and distribution the same every time.

Your results will be most accurate if your filling method is consistent.

Calculating fuel economy

1. Fill the fuel tank completely and record the initial odometer reading (in miles or kilometers).
2. Each time you fill the tank, record the amount of fuel added (in gallons or liters).
3. After at least three to five tank fill-ups, fill the fuel tank and record the current odometer reading.
4. Subtract your initial odometer reading from the current odometer reading.
5. Follow one of the simple calculations in order to determine fuel economy:

Calculation 1: Divide total miles traveled by total gallons used.
Calculation 2: Multiply liters used by 100, then divide by total kilometers traveled.

Keep a record for at least one month and record the type of driving (city or highway). This will provide an accurate estimate of the vehicle’s fuel economy under current driving conditions. Additionally, keeping records during summer and winter will show how temperature impacts fuel economy. In general, lower temperatures give lower fuel economy.

Driving style — good driving and fuel economy habits

Give consideration to the lists that follow and you may be able to change a number of variables and improve your fuel economy.

Habits

• Smooth, moderate operation can yield up to 10% savings in fuel.
• Steady speeds without stopping will usually give the best fuel economy.
• Idling for long periods of time (greater than one minute) may waste fuel.
• Anticipate stopping; slowing down may eliminate the need to stop.
• Sudden or hard accelerations may reduce fuel economy.
• Slow down gradually.
• Driving at reasonable speeds (traveling at 55 mph [88 km/h] uses 15% less fuel than traveling at 65 mph [105 km/h]).
• Revving the engine before turning it off may reduce fuel economy.
• Using the air conditioner or defroster may reduce fuel economy.
• You may want to turn off the speed control in hilly terrain if unnecessary shifting between the top gears occurs. Unnecessary shifting of this type could result in reduced fuel economy.
• Warming up a vehicle on cold mornings is not required and may reduce fuel economy.
• Resting your foot on the brake pedal while driving may reduce fuel economy.
• Combine errands and minimize stop-and-go driving.

Maintenance

• Keep tires properly inflated and use only recommended size.
• Operating a vehicle with the wheels out of alignment will reduce fuel economy.
• Use recommended engine oil. Refer to Maintenance product specifications and capacities in this chapter.
• Perform all regularly scheduled maintenance items. Follow the recommended maintenance schedule and owner maintenance checks found in scheduled maintenance information.

Conditions

• Heavily loading a vehicle or towing a trailer may reduce fuel economy at any speed.
• Carrying unnecessary weight may reduce fuel economy (approximately 1 mpg [0.4 km/L] is lost for every 400 lb [180 kg] of weight carried).
• Adding certain accessories to your vehicle (for example bug deflectors, rollbars/light bars, running boards, ski racks) may reduce fuel economy.
• Using fuel blended with alcohol may lower fuel economy.
• Fuel economy may decrease with lower temperatures during the first 8–10 miles (12–16 km) of driving.
• Driving on flat terrain offers improved fuel economy as compared to driving on hilly terrain.
• Transmissions give their best fuel economy when operated in the top cruise gear and with steady pressure on the gas pedal.
• Close windows for high speed driving.