In practice, the answer is no. The firing order is a fixed design choice built into the engine to balance forces, manage vibrations, and ensure reliable combustion. Changing it to gain mpg is not feasible for standard production engines and can reduce efficiency or cause drivability problems.
Firing order refers to the sequence in which cylinders ignite, and it is determined by the engine’s layout (inline, V, or flat) and crankshaft geometry. Engineers optimize it to minimize vibrations and mechanical losses while meeting power and efficiency goals, so any potential gains from altering firing order are negligible and largely outweighed by reliability concerns. Modern engines rely more on timing strategies, cylinder deactivation, and other technologies to improve fuel economy rather than changing the firing order.
What is firing order and why it matters
The firing order is the order in which each cylinder’s ignition occurs during a complete engine revolution. It is dictated by the engine’s physical design, including crank throws and camshaft configuration. In production engines, this order is chosen to optimize smoothness, balance, and durability, not to be a dial you turn for better mpg.
- Engine balance and vibration: An optimized sequence reduces shaking and mechanical losses, which can otherwise waste energy.
- Crankshaft and torsional dynamics: The order influences how the crankshaft flexes and transmits torque, affecting efficiency and durability.
- Manufacturability and reliability: Reordering firing would require a redesigned crank/cam setup and could compromise reliability.
- Compatibility with other technologies: Variable valve timing and cylinder deactivation rely on a stable firing pattern for predictable operation.
Because these factors are deeply rooted in hardware design, changing firing order after production is impractical and unlikely to yield meaningful mpg gains. In most cases, any marginal efficiency gains would be offset by reduced power delivery or handling issues.
What actually affects fuel economy?
Below are the main categories that influence mpg in typical consumer vehicles. The impact of these factors generally dwarfs any potential gains from changing firing order.
- Engine efficiency technologies: Direct injection, turbocharging, variable valve timing, and efficient combustion strategies.
- Air-fuel management and ignition timing: Precise control reduces pumping losses and maximizes usable energy from each combustion event.
- Drivetrain efficiency: Transmission design, gear ratios, and driveline losses affect how effectively engine power is converted to motion.
- Weight and aerodynamics: Lighter vehicles and better streamlined shapes reduce energy needed to maintain speed.
- Driving behavior and conditions: Aggressive acceleration, high speeds, excessive idling, and frequent stop-and-go driving lower mpg; cruise control and smooth acceleration help.
In practice, optimizing these factors yields meaningful fuel-economy gains, whereas changing the firing order offers no realistic path to better mileage in everyday driving.
Exceptions and caveats
Some high-performance or specialized engines experiment with alternative firing orders during development or for specific balance or packaging reasons. These cases are engineered for particular outcomes and are not intended to improve fuel economy in typical consumer vehicles. For ordinary cars, the firing order remains fixed by design.
Summary
Firing order is a hardware design parameter that cannot be practically adjusted to improve gas mileage in standard engines. Real mpg gains come from advanced engine technologies, lighter and more aerodynamic vehicles, efficient transmissions, and prudent driving habits. Understanding and optimizing these factors is the reliable path to better fuel economy.