1. Tune-Up and Maintenance:
* Properly functioning carburetor (if applicable): A properly tuned carburetor ensures the correct air/fuel mixture, maximizing combustion efficiency. This is crucial for older muscle cars. A poorly tuned carb can waste significant fuel.
* Spark plugs, wires, distributor cap and rotor: Worn components reduce ignition efficiency, leading to incomplete combustion and poor fuel economy. Replace with high-quality parts appropriate for your engine.
* Air filter: A clean air filter allows the engine to breathe properly. A clogged filter restricts airflow and reduces efficiency.
* Fuel filter: A dirty fuel filter restricts fuel flow, leading to poor performance and fuel consumption.
* Proper tire inflation: Under-inflated tires increase rolling resistance, lowering mileage. Maintain the recommended tire pressure.
* Regular oil changes: Using the correct weight oil and changing it regularly helps the engine run smoothly and efficiently.
2. Driving Habits:
* Gentle acceleration and braking: Avoid aggressive acceleration and hard braking. Smooth driving significantly impacts fuel economy.
* Maintain consistent speeds: Cruising at a steady speed, especially on the highway, is more efficient than constantly accelerating and decelerating.
* Avoid idling: Excessive idling wastes fuel. Turn off the engine if you'll be stopped for more than a minute or two.
* Use overdrive (if equipped): Many later muscle cars had overdrive transmissions. Use this gear whenever possible on the highway.
3. Modifications (with caveats):
* Performance improvements (rarely improve mileage): Ironically, many performance upgrades (e.g., high-performance camshafts, high-flow heads) actually *reduce* gas mileage. These are for performance, not efficiency.
* Overdrive transmission (if not equipped): Adding an overdrive transmission is a major undertaking but can yield the largest MPG improvement, however it is a costly and complex modification.
* Smaller tires (slightly improves mileage): Slightly smaller diameter tires will increase your RPMs for any given speed, but will decrease rolling resistance, potentially resulting in slightly better fuel economy. This change affects speedometer accuracy, though.
* Lightweight components (minor effect): Replacing heavy parts with lighter alternatives (e.g., aluminum wheels, fiberglass body parts) can marginally improve fuel economy, but this is often an expensive endeavor.
Realistic Expectations:
You should not expect drastic improvements in MPG. Even with all the above, a significant increase is unlikely. Muscle cars were designed for power, not efficiency, and that fundamental design remains. You might see a 5-10% improvement, but any more than that is probably unrealistic.
Before you start modifying: Consider the value of your car and the cost of modifications. Some changes, like a new transmission, might cost more than the potential fuel savings. It's crucial to weigh the costs and benefits carefully.
