* Optimal RPM Range: Every engine has an RPM range where it operates most efficiently. Driving at too low an RPM can cause the engine to work harder, actually *reducing* fuel efficiency. You'll likely notice sluggish acceleration and the engine struggling.
* Gear Selection: The key is to stay within the engine's efficient RPM range. This is often achieved by shifting to a higher gear sooner than you might normally. If you're constantly driving at very low RPMs, it might mean you're lugging the engine, which is inefficient and puts more stress on the engine.
* Driving Style: Gentle acceleration and maintaining a steady speed are far more impactful on fuel economy than simply focusing on RPM. Hard acceleration and frequent braking waste far more fuel than slightly higher RPMs during steady-state driving.
In short: Don't just aim for arbitrarily low RPMs. Instead, try to drive smoothly and shift to higher gears at appropriate speeds to keep the engine in its most efficient RPM range. Consult your owner's manual for information on the optimal RPM range for your Trailblazer's engine. You might find information online about typical fuel-efficient driving RPM ranges for your specific engine (e.g., searching for "2002 Chevy Trailblazer 4.2L optimal RPM").
