Yes, you can often improve an old car's gas mileage through a combination of maintenance, mindful driving habits, and, in some cases, minor upgrades. While you won't transform a classic V8 into a modern hybrid, gains of 5-15% are commonly achievable. The most significant improvements typically come from addressing basic maintenance items that directly impact engine efficiency.
The single biggest factor is often tire pressure. Under-inflated tires create excessive rolling resistance, forcing the engine to work harder. Check your tire pressure monthly and keep it inflated to the manufacturer's recommended PSI, which you can find on the driver's side door jamb. This simple, free action can yield immediate results.
Next, focus on the engine's core systems. Replacing a dirty air filter allows for optimal air flow, leading to more efficient combustion. Using the correct grade of motor oil (look for "energy conserving" on the API symbol) can reduce internal engine friction. A neglected oxygen sensor can provide incorrect data to the car's computer, causing it to waste fuel. Replacing a faulty one can offer one of the highest returns on investment for fuel economy.
Your own driving style has a massive impact. Aggressive acceleration and hard braking are major fuel wasters. Aim for smooth, gradual acceleration and anticipate stops to coast whenever possible. On the highway, using cruise control to maintain a steady speed is more efficient than fluctuating your speed manually. Also, reduce unnecessary weight by cleaning out your trunk and remove roof racks when not in use, as both create drag.
| Method | Approximate MPG Improvement | Relative Cost/Effort |
|---|
| Correct Tire Pressure | Up to 3% | Very Low / Free |
| New Air Filter | Up to 10% | Low |
| New Spark Plugs | 5-10% | Low to Medium |
| Fixing Faulty Oxygen Sensor | Up to 40% | Medium (if sensor is faulty) |
| Aggressive to Calm Driving | 15-30% on highways | Free |
| Using Recommended Motor Oil | 1-2% | Low |
| Reducing Idling | Varies (0 MPG while idling) | Free |
| Removing Excess Weight (100 lbs) | ~1-2% | Free |
Ultimately, improving an old car's mileage is about restoring its original efficiency through care and changing your habits. It won't be a miracle, but it will save you money at the pump.
