What is the best fuel additive to increase MPG?

The most reliable way to improve fuel economy with an additive is to use a high-quality PEA-based fuel system cleaner to restore lost efficiency, not to expect a miracle boost. For gasoline engines, reputable choices include Chevron Techron Concentrate Plus, Gumout Regane Complete, and Red Line SI-1, while diesel owners can consider multi-function additives like Stanadyne Performance Formula or Power Service Diesel Kleen. Expect small, realistic gains—typically 0–3%—unless your engine has significant deposit buildup, in which case the improvement can be more noticeable. Below, we explain what works, what doesn’t, and how to use additives effectively.

What fuel additives can actually help efficiency?

Modern engines and fuels already incorporate detergents, and many claimed “MPG boosters” don’t deliver measurable gains. The additives that consistently show benefit are those that clean fuel injectors and combustion chambers, which can restore lost efficiency caused by deposits. For gasoline engines, the gold-standard cleaning chemistry is polyetheramine (PEA). For diesel engines, products that combine detergents with cetane improvers and lubricity enhancers can help restore smooth combustion and reduce parasitic losses in fuel systems.

Gasoline engines: PEA detergents are the only proven option

PEA-based cleaners survive combustion and dissolve stubborn deposits on injectors and in the combustion chamber. If your injectors are partially clogged or spray patterns are degraded, a PEA cleaner can restore proper atomization and combustion, which may recover a bit of lost MPG. This is restoration, not a permanent “increase.” If your engine is already clean, you’re unlikely to see a meaningful change.

The following products are widely respected for their PEA content and track record, and they meet EPA registration requirements for fuel additives in the U.S.:

• Chevron Techron Concentrate Plus: Strong PEA formulation designed for periodic deep-cleaning of injectors and the combustion chamber.
• Gumout Regane Complete Fuel System Cleaner: PEA-based cleaner targeting injectors, intake valves in port-injected engines, and combustion chambers.
• Red Line SI-1 Complete Fuel System Cleaner: High PEA content, effective for heavy deposit situations and periodic maintenance.
• Use of Top Tier gasoline (not a bottle additive, but a detergent standard): Prevents deposit buildup over time and helps maintain factory MPG, with studies indicating cleaner engines and potential avoidance of 2–4% MPG loss versus lower-detergent fuels.

Any of these can help if deposits are the cause of lost MPG. For ongoing prevention, consistently using Top Tier gasoline often makes a bigger difference than frequently dosing bottled additives.

Diesel engines: cetane + detergent blends

Diesel additives that combine detergents (to keep injectors clean), cetane improvers (for smoother, quicker ignition), and lubricity enhancers (protecting pumps and injectors) can help maintain or recover efficiency. Gains tend to be modest unless there’s an underlying fuel quality or deposit issue, but smoother combustion and reduced injector drag can slightly improve MPG and drivability.

These diesel-focused additives are well-regarded for all-season use:

• Stanadyne Performance Formula: Detergent, cetane boost, lubricity, and corrosion protection; widely used in light- and heavy-duty diesels.
• Power Service Diesel Kleen +Cetane Boost: Cleans injectors and raises cetane; often used in warm weather for performance and economy.
• Hot Shot’s Secret Everyday Diesel Treatment (EDT): Multi-function package for detergency, cetane, and lubricity aimed at daily use.

These won’t transform fuel economy in a healthy engine, but they can restore efficiency and consistency, especially when fuel quality is variable or deposits have formed.

How much MPG gain should you expect?

Realistic expectations are key. Independent testing and agency reviews have not found any additive that reliably increases MPG in a clean, properly running engine. However, cleaning dirty injectors can reclaim lost efficiency. Typical outcomes are 0–3% improvement, sometimes more if deposits were severe. Using Top Tier gasoline can prevent the 2–4% fuel economy loss associated with heavier deposit formation observed in industry testing, effectively preserving the MPG your engine was designed to deliver.

How to use fuel additives effectively

The best results come from targeted use—clean when needed, then prevent re-accumulation. Here’s a simple plan to maximize the value of additives.

1. Check your owner’s manual: Ensure additives are permitted and avoid any that conflict with manufacturer guidance.
2. Start with a PEA cleaner (gasoline) or a reputable multi-function formula (diesel): Add to a near-empty tank, then fill up to the bottle’s specified gallons for proper concentration.
3. Run the full tank and evaluate: Note idle smoothness, throttle response, and hand-calculated MPG over at least two full tanks.
4. Repeat if heavily sooted or neglected: One more treatment may be warranted for severe deposits; otherwise, switch to preventive maintenance.
5. Prevent deposits: Use Top Tier gasoline (gas) or continue a modest-dose diesel additive in regions with variable fuel quality.
6. Avoid overuse: More is not better; overdosing can be wasteful and, in extreme cases, counterproductive.
7. Know the limits with GDI engines: In gasoline direct injection, in-tank cleaners won’t wash intake valves (fuel doesn’t pass over them). If intake valve deposits are suspected, separate cleaning methods are required.

Following a measured approach avoids unnecessary cost while ensuring you get any real, achievable MPG benefits from cleaning and prevention.

What won’t boost MPG

Many products are marketed as economy enhancers but don’t produce consistent, measurable gains in modern engines. Be skeptical of the following.

• Octane boosters when your engine doesn’t require higher octane: Higher octane doesn’t contain more energy; it prevents knock. Using more than required rarely improves MPG.
• “Ethanol treatment” claims promising better mileage: They may stabilize fuel or protect components but can’t change ethanol’s lower energy content versus pure gasoline.
• Oil or PTFE-based fuel additives and friction modifiers: Unproven for meaningful MPG gains via the fuel tank; use manufacturer-approved engine oils instead.
• Magnetic or “vortex” fuel gadgets: No credible evidence supports MPG improvements.
• Excessive two-stroke oil in diesel: Can harm emissions systems and is not a reliable path to better economy.

Sticking to chemistries with a track record—PEA detergents for gasoline and reputable multi-function packages for diesel—helps you avoid ineffective add-ons.

Bottom line and recommendations

There is no single “best” additive that boosts MPG in a healthy engine. The most effective approach is to restore and maintain cleanliness: use a PEA-based cleaner periodically in gasoline engines, choose Top Tier gasoline to prevent deposit formation, and, for diesels, use a trusted additive that combines detergency, cetane, and lubricity. Expect small but real gains only when there’s something to fix. For bigger improvements, driving habits, tire pressure, maintenance (plugs, filters, O2 sensors), and proper oil selection typically yield larger returns than any additive.

Summary

Best pick for MPG gains via additives: a PEA-based fuel system cleaner to restore lost efficiency (Chevron Techron Concentrate Plus, Gumout Regane Complete, Red Line SI-1) and consistent use of Top Tier gasoline to prevent future losses. Diesel owners can consider Stanadyne Performance Formula, Power Service Diesel Kleen, or Hot Shot’s Secret EDT. Expect modest improvements unless deposits are significant, and focus on overall maintenance and driving practices for the largest fuel economy gains.

What trick gets the best gas mileage?

What are easy hacks to make my car have better gas mileage? The easiest one is to slow down. Driving slower will almost always save you gas, especially from about 40mph and up. Accelerate slowly, but steadily. No jackrabbit starts. Don’t stop or slow down if you can help it. slowing down to speed up again wastes fuel.

Do MPG boosters work?

FICTION: Fuel Additives Can Increase MPG
These additives tend to be marketed as a way of increasing fuel economy, reducing emissions, or both. Except for one notable product, they are without a doubt a waste of your money because they do not work according to their claims.

Does Lucas oil increase MPG?

“By adding a bottle of fuel system cleaner or other Lucas Oil product, you can drive with peace of mind knowing your fuel system is working at its best, keeping you driving for miles and miles with reliable performance, better gas mileage and lower emissions.”

What improves gas mileage the most?

The best way to gain maximum gas mileage is to drive efficiently by maintaining a steady speed, avoiding rapid acceleration and hard braking, and observing the speed limit, especially above 50 mph. You can also significantly improve fuel economy through proper vehicle maintenance, including keeping tires correctly inflated, maintaining the correct oil grade, and changing air filters regularly. Lastly, reducing vehicle weight by removing unnecessary items and by minimizing air resistance through proper aerodynamic design further enhances fuel efficiency. 
Driving Techniques:

• Drive Smoothly: Opens in new tabAccelerate gently and brake gradually to prevent wasting fuel. 
• Maintain a Steady Speed: Opens in new tabUse cruise control on highways to maintain a constant speed, which is more fuel-efficient than varying your speed. 
• Observe the Speed Limit: Opens in new tabFuel economy decreases significantly as speeds exceed 50-60 mph, so staying within the speed limit is crucial for better mileage. 
• Anticipate Traffic: Opens in new tabLook ahead to anticipate stops and slow down gradually instead of braking hard. 
• Minimize Idling: Opens in new tabTurn off your engine when parked for extended periods, as idling wastes fuel. 

Vehicle Maintenance:

• Check Tire Pressure: Properly inflated tires reduce rolling resistance, improving fuel efficiency and extending tire life. 
• Use the Correct Oil: Using the manufacturer-recommended grade of motor oil can improve fuel efficiency by a few percentage points. 
• Maintain Engine Components: Regularly replace dirty air filters and spark plugs to ensure your engine runs efficiently and consumes fuel properly. 
• Regular Tune-Ups: Routine maintenance ensures your vehicle is operating at its best. 

Vehicle Condition:

• Lighten Your Load: Remove unnecessary weight from your vehicle, as every 100 pounds can reduce fuel economy. 
• Address Aerodynamic Drag: Remove roof racks or cargo carriers when not in use, as they create drag and decrease fuel efficiency, particularly at highway speeds. 
• Tighten the Gas Cap: A loose or missing gas cap can allow fuel to evaporate, reducing your fuel economy and costing you money.