For maximum fuel efficiency, an oscilloscope engine analyzer (left) confirms the condition of the points or module, rotor, cap, spark plugs, and cables. Distributor strobe machine (right) from the breaker point era has been adapted to service electronic distributors as well. Spark wires can be tested simply with a volt-ohmmeter. For off-road fuel efficiency, compare ohm readings of cables to factory specifications listed in a manual. Distributor strobe machine calibrates spark timing curves for maximize efficiency.