The Fuel Economy Tune-Up

The Fuel Economy Tune-Up

Fifty years ago a tune-up included air & fuel filters, PCV valve, ignition points & condenser, distributor cap & rotor, and spark plugs. Occasionally new ignition wires were added, and a carburetor rebuild was required.  In addition to parts installation, labor would include adjusting the gap on the points, setting ignition timing (twisting the distributor while using a timing light), and cleaning & adjusting the carburetor and PCV valve (if reusing the old one). Some engines also required a valve lash adjustment. As the decades rolled by, many of these parts & procedures were systematically eliminated by electronic controls.

With so few parts left to replace on today’s automobiles, and no adjustments possible (all adjustments are ECU controlled), what can be improved in a tune-up? The goal of the “Fuel Economy Tune-Up” is to not only restore factory performance, but exceed it. You should still clean the throttle body (pay attention to the PCV ports) and MAF (if equipped). Next, oxygen sensors are good for <7 years and/or <90k miles. Due to how the OBD II rules are worded, a lazy O2 sensor will not trip a code, even when it affects performance and economy. In fact, it can be comatose and still not trip a code! When replacing oxygen sensors, USE ONLY OEM REPLACEMENTS! Aftermarket replacements almost never work as well as the dealer supplied versions. I suspect it has something to do with calibrations. O2 sensors should be replaced like ignition wires were 50 years ago; occasionally, but definitely when needed.

Something to ponder: As you visit the different pages on this site, you will see numerous “upgrades” recommended. Pulstar Plugs, MPG Plus wires, and such. However, there is one area — and only one — where we overwhelmingly suggest OEM replacements, and that is the oxygen sensors. Our experience spans a decade and a half of testing, and no aftermarket O2 sensor has ever performed up to OEM standards.

Gasoline engines still use spark plugs, so upgrading to Pulstar Plugs will improve performance and fuel economy. Note that spark gaps may need to be reduced from stock specs (0.32” to 0.28”?). Engines with 2 valves per cylinder will benefit from indexing the plugs towards the head. If the engine has ignition wires, solid core wires (specifically Granatelli or MPG Plus wires) will deliver more of the ignition coil’s energy to the plugs. If it has a distributor, a brass terminal distributor cap (and matching rotor) will last longer and perform at peak longer (NAPA Belden or Blue Streak). See the Ignition page for more details.

The Fuel Economy Tune-Up could end there, or shop owners might offer different Packages where this is their Level 1 version. In salt belt areas (where stuff rusts out quickly due to road salt), a grounding package — including exhaust system grounding — could be Level 2. Other package options may include the Gadgetman Groove and/ or PCV modifications. Much can be bundled onto the Tune-Up category. The shop has flexible options.

Finally, we suggest you take emissions readings (see Eliminate Emissions Estimations) before and after. This can conclusively show your customer immediate benefits from your work in the form of emissions reductions. If your scan tool has print capabilities, a before and after capture of the data stream could be part of the documentation package.

The Fuel Economy Tune-Up can be a profitable mainstay offering for most shops. Fuel prices are breaking new records. People are already aware of the concept of the Tune-Up, so they’re open to the idea by default. It shouldn’t take much time to explain the difference between using cheap versus premium parts. The punch line is spend a little more now and save a lot more in the future.

FE2 - FE3 Depending

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