Can 0-Ohm Spark Plug Wires Improve MPG? Understanding Ignition Efficiency

With fuel prices constantly changing, drivers are always looking for ways to improve fuel economy without sacrificing horsepower.

Most people immediately think about tire pressure, driving habits, air filters, fuel injectors or engine tuning.

But one part of the engine is often overlooked:

The ignition system.

Every time your engine fires a cylinder, the ignition coil has to send electrical energy through the spark plug wire and ultimately across the spark plug gap.

Granatelli Motor Sports developed its 0-Ohm ignition wire technology around a simple idea:

Reduce unnecessary electrical resistance between the ignition coil and the spark plug.

Can that actually help fuel economy?

The answer is that it can help in certain applications, particularly when improving the efficiency and consistency of the ignition system.

What Does the Ignition System Have to Do With MPG?

Your engine makes power by burning a mixture of air and fuel inside each cylinder.

That combustion process begins with the spark plug.

If ignition is weak, inconsistent or compromised, combustion can also become less consistent.

When combustion is more stable and effective, the engine has a better opportunity to extract useful energy from the fuel it is already consuming.

Automotive engineering research has long recognized the relationship between ignition quality, combustion stability and engine efficiency.

SAE research has specifically examined how adequate spark energy and ignition-system characteristics can affect combustion efficiency.

That doesn't mean simply adding more voltage automatically creates better MPG.

It means the ignition event is an important part of the overall combustion process.

Where Spark Plug Wire Resistance Comes In

An ignition coil creates the electrical energy required to fire the spark plug.

That energy then has to travel through the secondary ignition circuit.

Traditional spark plug wires commonly contain resistance.

Resistance is often intentionally used to help control radio-frequency and electromagnetic interference.

But resistance also affects how electrical energy moves through the ignition circuit.

Research published by SAE has examined the effects of secondary ignition-circuit resistance on ignition-energy transfer.

Granatelli approached this problem differently.

Instead of using a conventional high-resistance suppression conductor, Granatelli developed an extremely low-resistance ignition wire combined with technology designed to control RFI and EMI.

The objective is to provide a lower-resistance electrical path from the ignition source to the spark plug without creating the electronic interference associated with traditional solid-core racing wires.

Why Are They Called 0-Ohm Wires?

Granatelli performance ignition wires are commonly referred to as 0-Ohm wires because they are engineered to provide extremely low electrical resistance.

The technology behind the design is covered by U.S. Patent No. 7,185,622.

The patent describes ignition-wire designs capable of operating at extremely low resistance levels, including embodiments providing substantially no resistance, while also incorporating methods for suppressing radio-frequency emissions.

That combination is important on modern vehicles.

You don't simply want low resistance.

You also need an ignition wire that can operate around:

Engine-control modules
Electronic sensors
Radios
Data systems
Modern OBD-II electronics

Granatelli's design was developed to address both sides of that equation.

Can Lower Resistance Automatically Increase MPG?

No.

Fuel economy is far too complicated for any single component to guarantee a specific MPG increase on every vehicle.

Your actual MPG can be affected by:

• Driving style

• Vehicle weight

• Tire pressure

• Aerodynamics

• Engine condition

• Fuel quality

• Gear ratios

• Traffic

• Weather

• Tuning

• Spark plugs

• Ignition coils

• Fuel injectors

• Engine modifications

What reducing ignition-wire resistance can do is improve one portion of that system:

The electrical path between the ignition source and the spark plug.

If an engine's existing ignition wires have substantial resistance, deterioration or other losses, replacing them with a properly designed low-resistance wire can provide the ignition system with a more direct electrical path.

Granatelli MPG Plus Testing

Granatelli took this idea further with its MPG Plus ignition-wire program.

Granatelli testing has reported fuel-economy increases of up to 15% in certain tested applications.

That number is important to put into context.

We are not saying every car, truck or SUV will automatically gain 15% MPG simply by installing spark plug wires.

Results depend heavily on the vehicle and its existing condition.

A vehicle with an aging ignition system, high-resistance wires or inconsistent combustion may have considerably more room for improvement than a perfectly maintained vehicle with new factory ignition components.

Still, the testing demonstrates why ignition-system efficiency should not automatically be ignored when looking for ways to improve vehicle efficiency.

Think About the Entire Ignition Path

A good way to understand this is to look at the complete path:

Ignition Coil → Spark Plug Wire → Spark Plug → Combustion

The coil creates the electrical energy.

The wire carries it.

The spark plug uses that energy to initiate combustion.

Every part of that chain matters.

You wouldn't intentionally install a restriction in your air intake and expect maximum airflow.

You wouldn't intentionally restrict your exhaust system and expect maximum exhaust flow.

Granatelli applies similar thinking to ignition wiring:

Why introduce unnecessary electrical resistance between the coil and spark plug?

Can 0-Ohm Wires Also Increase Horsepower and Torque?

Fuel economy isn't the only reason to improve ignition-energy delivery.

Granatelli's testing across numerous vehicle applications has shown gains of as much as:

15 rear-wheel horsepower

and

17 lb-ft of rear-wheel torque

in certain tested applications.

Just like the MPG results, those are maximum reported test results and should not be interpreted as guaranteed gains for every vehicle.

The amount of improvement depends heavily on the engine combination and the ignition system being replaced.

When Can Ignition Improvements Matter the Most?

Ignition-system performance becomes increasingly important when combustion conditions become more demanding.

Examples include:

High-Mileage Vehicles

Older ignition wires can deteriorate over time through heat cycles, vibration and contamination.

Performance Engines

Engines making additional horsepower place greater demands on almost every supporting system.

Turbocharged and Supercharged Engines

Higher cylinder pressures make the ignition environment more demanding.

High-Compression Engines

Increased cylinder pressure requires a strong, consistent ignition event.

E85 Applications

Performance fuel combinations may have ignition requirements different from an otherwise stock gasoline engine.

Daily Drivers

A daily-driven car or truck can benefit from an ignition system that is operating consistently, especially if the factory wires are aging or have accumulated substantial mileage.

What About Modern Computer-Controlled Vehicles?

This is where simply installing old-school solid-core racing wires can become a problem.

Low-resistance solid conductors can generate RFI and EMI that may interfere with modern electronics.

Granatelli's technology is designed specifically to combine very low resistance with electrical-noise suppression.

The patented design includes methods of suppressing radio-frequency emissions while maintaining a highly conductive path between the ignition source and spark plug.

That allows Granatelli to offer 0-Ohm technology for many modern computer-controlled applications.

MPG Is About Efficiency, Not Magic

It's important to understand what we're really talking about.

A Granatelli wire does not create gasoline.

It doesn't change your transmission gearing.

It doesn't make a 6,000-pound truck suddenly behave like a compact economy car.

The goal is much simpler:

Help the ignition system deliver its available energy efficiently and consistently to the spark plug.

When you are trying to improve fuel economy, small improvements throughout a vehicle can add up.

Good tire pressure matters.

Proper maintenance matters.

Clean injectors matter.

Correct tuning matters.

And proper ignition matters.

Horsepower and Fuel Economy Don't Always Have to Be Opposites

Performance modifications are often associated with using more fuel.

But efficiency and performance are closely connected.

An engine that converts more of its fuel's available energy into useful cylinder pressure can potentially produce more useful work from that combustion event.

That's why ignition technology can be relevant to both sides of the conversation:

Horsepower and torque for the performance enthusiast.

Fuel efficiency for the daily driver.

The common denominator is more consistent combustion.

The Granatelli Difference

Depending on the application, Granatelli 0-Ohm ignition wires feature:

• Near-zero resistance conductor technology

• Patented RFI and EMI suppression technology

• Stainless-steel conductor construction

• High-temperature silicone boots

• Fiberglass-reinforced jackets

• Direct-fit vehicle-specific configurations

• High-temperature options

• Ceramic boot options for extreme heat

• OBD-II compatible designs

• Hundreds of vehicle fitments

The goal is not simply to manufacture another replacement spark plug wire.

The goal is to improve the electrical connection between the ignition system and the spark plug.

The Bottom Line

Can spark plug wires improve MPG?

Under the right conditions, improving the ignition system can contribute to improved combustion consistency and efficiency.

Granatelli's MPG Plus testing has reported fuel-economy improvements of up to 15% in certain applications, while Granatelli's broader 0-Ohm testing has also demonstrated horsepower and torque gains on tested vehicles.

Your results will depend on your vehicle, engine condition, existing ignition components and driving conditions.

But the basic engineering principle remains simple:

Reduce unnecessary resistance and provide the ignition system with an efficient electrical path to the spark plug.

Because every mile — and every horsepower — starts with combustion.

Learn More About Granatelli 0-Ohm Technology

For additional technical information, link readers to:

Granatelli Motor Sports – Ignition Coils & 0-Ohm Wire Technology

U.S. Patent 7,185,622 – Low-Resistance Ignition Wire Technology

SAE International – Spark Ignition Circuit Energy Characterization

Then link directly to the Granatelli Ignition Wires collection so readers can find the correct wire set for their vehicle.