Note: Since driving habits can have a significant influence on fuel economy, verify the concern before starting an in-depth diagnosis. Also, the following external factors could contribute to "poor fuel economy" conditions:

• Stop/Go City Driving
• Tire Pressure/Size
• Vehicle Loads (Trailer Towing, etc.)
• Extended Winter Warm-up Conditions
• High Speed Driving
• Axle Ratio
• Speedometer Gear Ratio
• Road/Weather Conditions
• After Market Add-ons
• Short-Run Operations
• Customer Expectations/Driving Habits