Operation CHARM: Car repair manuals for everyone.

Poor Fuel Economy

DEFINITION:
Fuel economy, as measured by an actual road test, is noticeably lower than expected. Also, economy is noticeably lower than it was on this car at one time, as previously shown by an actual road test.

CHECK:
- Engine thermostat for being stuck open or for wrong heat range.
- Fuel pressure.
Check owner's driving habits.
- Is A/C "ON" full time?
- Are tires at correct pressure?
- Are excessively heavy loads being carried?
- Is acceleration too heavy, too often?
- Suggest driver read "Driving For Best Fuel Economy" in owner's manual.
Check air cleaner element for dirt contamination.
Check for proper calibration of speedometer.
Visually (physically) Check:
- Vacuum hoses for splits, kinks and proper connections as shown on vacuum hose routing diagram information label.
- Ignition wires for cracking, hardness and proper connections.
Check ignition timing. See Emission Control Information Label.
Remove spark plugs. Check for cracks, wear, improper gap, burned electrodes or heavy deposits. Repair or replace, as necessary.
Check compression.
Check for dragging brakes.
Suggest owner fill fuel tank and recheck fuel economy.
Check for exhaust system restriction.