We researched, compared, and evaluated the top engine degreasers on the market using manufacturer specifications, safety standards, and aggregated owner feedback. Our guide highlights the best options for cutting through heavy oil buildup, from water-based solutions to solvent sprays. Whether you need a gentle cleaner or a heavy-duty degreaser, we have a pick for you.
| Photo | Product | Score | Buy |
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Gunk Original Engine Degreaser Best Overall Solvent-based, 15 oz aerosol |
9.0 | 🛒 Check Price |
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Simple Green Pro HD Heavy-Duty Cleaner Best Eco-Friendly Water-based, biodegradable, 1 gallon concentrate |
8.7 | 🛒 Check Price |
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Chemical Guys Signature Series Orange Degreaser Best Scent Water-based, citrus-scented, 16 oz concentrate |
8.3 | 🛒 Check Price |
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Purple Power Concentrated Degreaser Best Value Water-based, alkaline, 1 gallon concentrate |
8.1 | 🛒 Check Price |
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CRC Heavy Duty Engine Degreaser Best Solvent Solvent-based, 15 oz aerosol |
7.8 | 🛒 Check Price |
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Meguiar's D10801 Super Degreaser Best for Detailing Water-based, pH neutral, 1 gallon concentrate |
7.3 | 🛒 Check Price |
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Zep Heavy Duty Citrus Degreaser Best Citrus Water-based, citrus-scented, 1 gallon concentrate |
7.0 | 🛒 Check Price |
1. Gunk Original Engine Degreaser: Best Overall
The Gunk Original Engine Degreaser is a classic choice for removing engine oil and grease. Based on owner feedback and the spec sheet, its solvent-based formula quickly penetrates and dissolves heavy buildup. It sprays on easily and rinses off cleanly. However, the strong chemical odor means it is best used outdoors or with proper ventilation.
This degreaser is ideal for DIYers tackling a messy engine bay. But if you are sensitive to fumes or need a biodegradable option, consider a water-based alternative. It may not be suitable for sealed electrical components.
- Powerful solvent formula dissolves heavy grease and oil
- Spray-on, rinse-off application with no scrubbing needed
- Safe for most engine components and metals
Pros: Deep cleaning action on caked-on grime; Fast acting, reduces cleanup time
Cons: Strong fumes require good ventilation
2. Simple Green Pro HD Heavy-Duty Cleaner: Best Eco-Friendly
Simple Green Pro HD is a water-based degreaser that is safer for the environment and your skin. In our evaluation, it performed well on moderate oil deposits but required agitation for baked-on grime. It is a popular choice among those who prioritize sustainability.
If you need a solvent-free cleaner that is gentle on the planet, this is a solid pick. However, for extreme grease, you might need a stronger product or multiple applications. It is not ideal for quick spray-and-rinse jobs.
- Non-toxic and biodegradable formula
- Concentrated, dilutes up to 1:10 for light degreasing
- Works on engines, tools, and parts
Pros: Environmentally friendly and low odor; All-around for multiple cleaning tasks
Cons: May need more scrubbing on heavy grease
3. Chemical Guys Signature Series Orange Degreaser: Best Scent
The Chemical Guys Orange Degreaser offers a pleasant citrus aroma that makes engine cleaning more enjoyable. Based on owner reviews, it works well for routine maintenance but struggles with thick, old oil deposits. It is a water-based formula that is safe on most surfaces.
This degreaser is perfect for car enthusiasts who want a pleasant cleaning experience. However, if you are dealing with a severely greasy engine, you may need a stronger solvent-based product. Skip this if you need maximum power.
- Pleasant orange scent masks chemical odor
- Concentrated formula for custom dilution
- Safe on painted surfaces and metals
Pros: Great smell compared to other degreasers; Effective on light to medium oil
Cons: Not as potent on heavy caked-on grease
4. Purple Power Concentrated Degreaser: Best Value
Purple Power is a budget-friendly degreaser that punches above its weight. In our research, it effectively removes engine oil when used undiluted. However, its alkaline nature means it can etch aluminum parts if not rinsed promptly. Owner feedback highlights its cost-effectiveness.
This is a great choice for those on a budget who need heavy-duty cleaning. But it requires careful handling and quick rinsing. Not recommended for aluminum engines or for those who prefer a milder cleaner.
- Highly concentrated, dilutes up to 1:4 for heavy duty
- Cuts through oil and grease quickly
- Budget-friendly per use
Pros: Excellent value for the price; Strong cleaning power when used full strength
Cons: Can be harsh on aluminum if left too long
5. CRC Heavy Duty Engine Degreaser: Best Solvent
CRC Heavy Duty Engine Degreaser is a solvent-based cleaner that excels at breaking down stubborn oil deposits. According to the spec sheet, it evaporates quickly, making it ideal for spot cleaning. However, its flammability and strong fumes limit its use to well-ventilated areas.
This product is best for mechanics who need a fast-acting degreaser for small parts. It is not suitable for large engine bays or for users who prefer water-based safety. Skip it if you want a non-flammable cleaner.
- Fast evaporating formula leaves no residue
- High solvency for tough grease
- Foaming action clings to vertical surfaces
Pros: Excellent at dissolving thick grease; Dries quickly without water rinsing
Cons: Flammable, requires caution near hot engines
6. Meguiar's D10801 Super Degreaser: Best for Detailing
Meguiar’s D10801 is a pH neutral degreaser designed for auto detailing. Based on owner feedback, it works well for light oil and road grime but struggles with thick engine grease. It is safe on paint and wax, making it a good choice for show cars.
If you need a gentle cleaner that won’t strip wax, this is a solid option. However, for heavy engine oil, you will need a stronger product. Skip this if you are dealing with a severely greasy engine.
- pH neutral formula safe on wax and clear coat
- Dilutable for various cleaning tasks
- Leaves a clean, streak-free finish
Pros: Gentle on painted surfaces; Multi-purpose for exterior and engine use
Cons: Less effective on heavy oil buildup
7. Zep Heavy Duty Citrus Degreaser: Best Citrus
Zep Heavy Duty Citrus Degreaser uses d-limonene from citrus to cut through oil. In our evaluation, it performed adequately on moderate grease but needed extra dwell time and scrubbing for heavy deposits. It is a safer choice for those concerned about chemicals.
This degreaser is good for light maintenance and eco-conscious users. However, for serious engine cleaning, it may not be enough. Skip this if you need a quick, powerful degreaser.
- Citrus-based solvent alternative
- Biodegradable and low odor
- Works on grease, oil, and tar
Pros: Pleasant citrus scent; Safer alternative to harsh solvents
Cons: Requires more effort on tough grease
Frequently Asked Questions
Can I use a degreaser on a hot engine?
It is generally not recommended to apply degreaser on a hot engine. Most solvent-based degreasers are flammable, and water-based ones can evaporate too quickly or cause thermal shock. Always let the engine cool to a warm but not hot temperature before cleaning.
How do I protect electrical components when degreasing?
Cover sensitive parts like the alternator, distributor, and air intake with plastic bags or aluminum foil. Use a low-pressure water rinse and avoid direct spray on electrical connections. Allow the engine to dry completely before starting.
What is the difference between solvent-based and water-based degreasers?
Solvent-based degreasers are stronger and evaporate quickly, but are flammable and have strong fumes. Water-based degreasers are safer, biodegradable, and have lower odor, but may require more scrubbing for heavy grease.
How often should I degrease my engine?
It depends on driving conditions and personal preference. For most drivers, degreasing once or twice a year is sufficient. If you notice oil leaks or heavy buildup, clean it more often to prevent dirt accumulation and make leak detection easier.
Can I use engine degreaser on other parts of my car?
Yes, many degreasers are safe for wheels, tires, and tools. However, check the label for compatibility with painted surfaces and plastics. Some degreasers can damage clear coat or rubber if left on too long.
Our Verdict
Our top pick is the Gunk Original Engine Degreaser for its powerful solvent action and ease of use. For an eco-friendly alternative, the Simple Green Pro HD Heavy-Duty Cleaner offers excellent value and safety.
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