A truly good automotive degreaser is the difference between a five minute wipe down and an hour of scrubbing with a wire brush. Whether you are cleaning a grease caked engine bay, a tar splattered undercarriage, or a workbench coated in years of oil, the right formula loosens the grime so it rinses away instead of smearing around. We put seven of the most popular degreasers through real shop conditions to see which ones genuinely dissolve grease and which ones just smell strong.
Below you will find our top picks ranked by cleaning power, ease of rinsing, surface safety, and how much elbow grease they save you. We tested each on hardened engine grease, road tar, brake dust, and general oily buildup so you can pick the one that matches your job instead of guessing in the store aisle.
| Photo | Product | Score | Buy |
|---|---|---|---|
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Chemical Guys Signature Series Orange Degreaser Best Overall Concentrated citrus-based formula, dilutable up to 10 to 1, 1 gallon |
9.5 | 🛒 Check Price |
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Meguiar's Super Degreaser D10801 Best for Detailers Professional concentrate, dilutes from 4 to 1 up to 20 to 1, 1 gallon |
9.3 | 🛒 Check Price |
 |
Simple Green Pro HD Heavy-Duty Cleaner Best Water-Based Non-toxic water-based concentrate, dilutes from 1 to 1 to 30 to 1, 1 gallon |
9.1 | 🛒 Check Price |
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Gunk Engine Brite Original Engine Degreaser EB1 Best Engine Specialist Solvent-based foaming engine spray, ready to use, 15 ounce aerosol |
8.9 | 🛒 Check Price |
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WD-40 Specialist Machine and Engine Degreaser Best Foaming Spray Bio-based foaming spray, ready to use, 18 ounce trigger bottle |
8.7 | 🛒 Check Price |
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Purple Power Industrial Strength Cleaner and Degreaser Best Value Concentrate Concentrated industrial cleaner, dilutable, 1 gallon |
8.5 | 🛒 Check Price |
 |
Sonax Engine Degreaser Best Premium Pick Ready-to-use spray engine cleaner, 16.9 ounce trigger bottle |
8.2 | 🛒 Check Price |
1. Chemical Guys Signature Series Orange Degreaser: Best Overall
Chemical Guys Orange Degreaser earned our top spot because it does the one thing a degreaser must do, it dissolves grease fast and rinses clean without leaving a residue. On a neglected engine bay caked with oily film, a 4 to 1 dilution loosened the grime in under a minute of dwell time, and a light agitation with a brush let most of it sheet off with a hose. The citrus base means it works on the chemistry of the grease rather than just smearing it, and the orange scent is a genuine relief compared to the gasoline like smell of older solvent degreasers.
The honest weakness is that this is a concentrate, so results depend entirely on getting your dilution right. Spray it on full strength near sensitive plastics or freshly waxed paint and it can dull or strip them, so you have to respect the mix ratios on the label. It also disappears faster than you expect once you start tackling truly filthy projects, since heavy grease wants a stronger mix. Get the dilution dialed in, though, and nothing else here matches its all around performance and surface safety.
- Citrus solvent power that lifts grease without harsh petroleum smell
- Highly concentrated so one gallon mixes into many bottles
- Safe on most painted, plastic, rubber, and metal surfaces when diluted
Pros: Outstanding grease cutting for engine bays and wheels; Pleasant orange scent instead of chemical fumes; Dilution flexibility makes it work for light or heavy jobs
Cons: Needs proper dilution or it can be too aggressive on delicate trim; Concentrate runs through quickly on very greasy projects
2. Meguiar's Super Degreaser D10801: Best for Detailers
Meguiar’s Super Degreaser is the bottle you see in a lot of professional detailing bays, and after testing it is easy to understand why. The dilution range is the widest in this guide, so the same jug handles a grimy engine at 4 to 1 and a lightly soiled carpet at 20 to 1. On road film and brake dust around the wheels it cut through quickly and rinsed without that tacky leftover feel that cheaper products can leave behind. For anyone who wants a single product to cover many jobs, this is the most flexible option we tried.
The catch is that it ships as a bare concentrate jug with no spray bottle, so you need to supply your own sprayer and mix it yourself before you can use it. That is normal for pro grade products but can surprise a first time buyer expecting a ready to go bottle. We also noticed that the strongest dilution, if left to dwell too long on bare aluminum, can start to dull the finish, so a quick work and rinse approach is best. Used as intended, it is a reliable workhorse that punches above its category.
- Detailing grade formula trusted in professional shops
- Wide dilution range from heavy engine work to light interior cleaning
- Rinses freely without leaving a sticky film
Pros: Versatile across engines, wheels, tires, and upholstery; Strong cleaning power even at moderate dilutions; A little goes a long way
Cons: Comes as a plain jug with no spray trigger included; Strongest mixes can be harsh on bare aluminum if left too long
3. Simple Green Pro HD Heavy-Duty Cleaner: Best Water-Based
Simple Green Pro HD is the pick for anyone who wants serious grease cutting without the eye watering fumes of a heavy solvent. This is the heavy duty industrial version, not the everyday all purpose Simple Green, and the difference shows. It is non-corrosive on most metals including aircraft aluminum, which makes it a favorite for people cleaning engines, tools, and machined parts where a harsh degreaser might cause pitting. On greasy hand tools and a dirty lawn mower deck it lifted the buildup cleanly once we mixed it strong.
Because it is water-based rather than solvent heavy, it does have a limit. Truly hardened, baked-on grease on a hot exhaust manifold sometimes needed a second application and a little more agitation than a solvent product would. On thick road tar it was the weakest of our heavy hitters. So if your main enemy is asphalt and tar, look elsewhere, but if you want a strong, lower toxicity degreaser that is gentle on metals and your lungs, this is an excellent and genuinely versatile choice.
- Water-based and non-corrosive on most metals
- No bleach, ammonia, or harsh petroleum solvents
- Broad dilution range for engines, tools, and parts
Pros: Safer to handle around skin and aircraft grade aluminum; Very strong cleaner once diluted correctly; Versatile for shop, garage, and household degreasing
Cons: Heavy baked-on grease may need two passes; Less aggressive than pure solvent degreasers on tar
4. Gunk Engine Brite Original Engine Degreaser EB1: Best Engine Specialist
Gunk Engine Brite has been the go to engine degreaser in countless garages for decades, and the original solvent formula still earns its reputation. This is a no mixing, ready to spray product, and the foam clings to vertical engine surfaces so the solvent has time to break down decades of baked grease. On a genuinely filthy older engine block, it dissolved the kind of hardened grime that water-based cleaners struggle with, then rinsed off to reveal bare metal. If a grungy engine bay is your specific problem, this is purpose built for exactly that.
The trade off is that this is an old school petroleum solvent, so it smells strong and you really do need to protect electrical connectors, the alternator, and any exposed sensors before you spray and rinse. It is also less of a general purpose product than the concentrates above, since the aerosol can is dedicated to engine work rather than tires, carpets, or tools. Treat it as a specialist rather than an all rounder, follow the prep steps, and it delivers results that are hard to beat on engine grease.
- Foaming spray that clings to vertical engine surfaces
- Solvent strength formulated specifically for engine grease
- Ready to use with no mixing required
Pros: Excellent on thick, old engine grease; Foam sticks where you spray it for better dwell; No dilution or sprayer needed
Cons: Strong petroleum solvent odor; You must cover sensitive electrical components before use
5. WD-40 Specialist Machine and Engine Degreaser: Best Foaming Spray
WD-40’s Specialist Machine and Engine Degreaser leans on a thick, clinging foam and a bio-based solvent blend to attack grease while keeping the odor more tolerable than classic aerosol degreasers. The trigger bottle gives you precise control, and the foam stays put on engine components and machinery long enough to actually penetrate the grime rather than dripping straight to the floor. On greasy machine parts and a chain caked in oily buildup, it loosened the gunk effectively and wiped away with a rag, which makes it handy for shop equipment as well as engines.
Where it falls short is coverage and versatility. Because it is a ready to use foam rather than a concentrate, a single bottle does not stretch nearly as far as a diluted gallon, so for big recurring jobs the cost per clean is less appealing. It is also focused on machinery and engines, so it is not the product you reach for to clean interior fabric or do light general degreasing. As a targeted, lower odor foaming degreaser for mechanical parts, though, it is a genuinely convenient and effective option.
- Thick foam clings to grease for deep penetration
- Bio-based solvent blend with lower odor
- Trigger spray bottle for controlled application
Pros: Strong clinging foam that does not run off immediately; Milder smell than traditional solvent aerosols; Convenient ready to use trigger sprayer
Cons: Single bottle covers less area than a diluted concentrate; Not as flexible across light cleaning tasks
6. Purple Power Industrial Strength Cleaner and Degreaser: Best Value Concentrate
Purple Power is the bottle a lot of people quietly keep on the garage shelf because it cuts through heavy grease and gives you a lot of cleaning for very little effort. As an industrial strength concentrate, it dilutes down to handle everything from engine grime and oily tools to greasy concrete floors. In our testing a moderate dilution made short work of caked-on grease on a transmission case, and the gallon jug stretches into a generous amount of usable cleaner, which is why it remains a long standing favorite for high volume work.
The honest weakness is that it is aggressive, and that aggression cuts both ways. Used at or near full strength it can etch or dull bare aluminum and damage paint and clear coat, so you must dilute it properly and avoid letting it dry on sensitive surfaces. You will also want gloves, because the concentrate is hard on skin. It is not the most refined or surface safe option in this guide, but for raw grease cutting power that goes a long way, it offers tremendous value.
- Industrial strength concentrate that dilutes for many jobs
- Strong cleaning power on heavy grease and grime
- Large gallon size for high volume cleaning
Pros: Goes a long way thanks to dilution flexibility; Cuts through tough grease and oil quickly; Works on engines, tools, concrete, and more
Cons: Aggressive at full strength, can dull aluminum and paint; Requires gloves and care when handling concentrated
7. Sonax Engine Degreaser: Best Premium Pick
Sonax brings its European detailing pedigree to engine cleaning with a ready to use spray that is tuned for the plastics, hoses, and seals found in modern engine bays. The appeal here is balance, it cleans light to moderate grime well while being noticeably gentler on the delicate components a newer engine is full of. The process is simple, spray it on, let it dwell, agitate lightly, and rinse, and on a recent model engine with normal road film it left the bay looking refreshed without any concern about damaging connectors or rubber.
The compromise that keeps it lower in our ranking is raw power. Faced with the kind of decades old, hardened grease that the Gunk and Purple Power formulas shrug off, the Sonax needed more passes and still left some stubborn deposits behind. The bottle is also on the smaller side, so it is not the economical choice for big or frequent jobs. If you maintain a modern engine and prioritize surface safety and ease of use over brute force, though, this premium pick is a refined and reassuring option.
- European formula engineered for modern engine bays
- Ready to use spray that requires no mixing
- Designed to be gentle on hoses, seals, and plastics
Pros: Surface friendly on modern engine plastics and rubber; Easy spray, dwell, and rinse process; Effective on light to moderate engine grime
Cons: Less aggressive on extremely heavy baked grease; Smaller bottle does not cover large recurring jobs
Frequently Asked Questions
What is the best degreaser for cleaning an engine bay?
For most engine bays, a concentrated citrus degreaser like the Chemical Guys Signature Series Orange Degreaser offers the best balance of cleaning power and surface safety, since you can dilute it strong for heavy grease or light for routine cleaning. If you are facing decades of hardened, baked-on grease, a dedicated solvent product like Gunk Engine Brite cuts through it faster. Whatever you choose, always cover the alternator, exposed sensors, and electrical connectors before spraying, work in sections, and rinse thoroughly so no residue is left behind.
Is a water-based or solvent-based degreaser better for automotive use?
It depends on the job. Water-based degreasers such as Simple Green Pro HD are safer to handle, produce far fewer fumes, and are gentle on metals like aluminum, which makes them ideal for tools, parts, and general cleaning. Solvent-based degreasers like Gunk Engine Brite are more aggressive and excel at dissolving thick, hardened engine grease and road tar that water-based products struggle with. Many people keep one of each, a water-based concentrate for everyday work and a solvent product for the worst grime.
Will automotive degreaser damage my car's paint or clear coat?
It can if you use it carelessly. Strong concentrates like Purple Power can dull or etch paint and bare aluminum if applied at full strength or allowed to dry on the surface. To stay safe, dilute concentrates to the recommended ratio, work in the shade rather than in direct sun, do not let the product dry, and rinse promptly and thoroughly. Surface friendly formulas like the Chemical Guys and Sonax options are far more forgiving on trim and plastics when used as directed, but rinsing well is always the key step.
How long should I let degreaser sit before rinsing?
For most automotive degreasers, a dwell time of one to three minutes is the sweet spot. You want to give the formula enough time to break down the grease, but you do not want it to dry on the surface, which can cause streaking or damage. On heavy, hardened grease, agitate with a brush during the dwell and consider a second application rather than simply leaving the first coat on longer. On hot surfaces like an exhaust manifold, let the part cool first, because heat makes the product evaporate and dry too quickly.
Can I use these degreasers on tires, wheels, and undercarriage?
Yes, and that versatility is one reason concentrates are so popular. A diluted all purpose degreaser like Meguiar’s Super Degreaser or Chemical Guys Orange works well on tires, wheel wells, and greasy undercarriage components, lifting brake dust, road film, and oily grime. For wheels with a delicate finish or coated surfaces, use a milder dilution and avoid letting the product sit. On the undercarriage, a stronger mix of an industrial concentrate handles caked-on grease, just protect any nearby rubber bushings and rinse everything well afterward.
Our Verdict
After testing all seven on real grease, our top pick is the Chemical Guys Signature Series Orange Degreaser, which combines strong citrus cutting power, a flexible dilution range, and genuine surface safety that makes it the most well rounded choice for engines, wheels, and general automotive grime. Our runner up is the Meguiar’s Super Degreaser D10801, a professional grade concentrate with an even wider dilution range that earns its place in detailing bays. If your specific battle is decades of hardened engine grease, the Gunk Engine Brite remains the specialist worth keeping on the shelf.
