Best Degreasers Tested: Which Cleaners Actually Cut Grease, Oil, and Mildew

Introduction

Degreaser marketing claims are easy to find and hard to verify. Nearly every bottle promises to dissolve grease fast, so the only reliable way to sort the contenders is to put them through identical, genuinely dirty tests. We lined up 13 popular cleaners, from dish soap to industrial concentrates, and tested each one on oil-soaked cloth, hardened grease, stained concrete, and mildewed siding.

Some products lived up to their names. Others, quite literally, goofed off. Here is what actually worked.

How We Tested

Four separate tests were run with every product used according to its own label instructions, diluted where the manufacturer required it and used full strength where allowed. For the first test, white cleaning cloths were cut into equal pieces, saturated with dark used diesel engine oil, and soaked in each cleaner. Every jar got the same treatment: 30 minutes of soak time plus a vigorous 30-second shake, then rinsing in clean water. Pricing ranged from a $6 dish detergent to a $23 OxiClean.

The results were judged in four categories: oil removal from cloth, grease dissolving, oil-stained concrete cleaning, and mildew removal. Scores were averaged across all four, which favors the all-arounder rather than a one-test specialist.

Top Performer Overall: OxiClean Degreaser

At $23, OxiClean is one of the pricier options in the lineup, but its all-around consistency won out. It finished second in the oil-on-cloth test, performed very well on concrete stains where it took first place, and was among the strongest mildew removers. It claims to be great for grease and grime, and for severe jobs no dilution is required.

This is the pick if you want a single bottle that holds up in every scenario rather than excelling in just one. Its worst finish across any category was still solidly mid-pack, which is exactly what an average score of 3.25 demands.

Best Value All-Rounder: Zep Heavy-Duty Citrus Degreaser

The $12 Zep concentrated citrus degreaser took first place in the oil-on-cloth test, arguably the best single result of the entire comparison, and placed second overall on the combined score. Its bright orange color made visual progress checks tricky, but the results after rinsing spoke for themselves. It also performed strongly on mildew, earning a top-tier rating alongside the best in that test.

Made in the USA and usable at full strength for tough soils, Zep is the strongest pick for anyone focused on grease and oil removal who also wants respectable mildew performance without paying premium prices.

Best for Grease: Super Clean

At just $6, Super Clean is the bargain of the group. It won the grease test outright, reducing a hardened glob of grease to what could only be described as melted consistency after 24 hours of soaking, and it came in third overall across all four categories. It comes ready to use in a spray bottle and claims to dissolve grease super easy and super fast, and the claims held up against concentrates costing three times as much.

If you exclude the cloth category, Super Clean actually takes the top overall spot with an average finish of 2.67, edging out everything else. It is designed for engines, tools, grills, driveways, concrete, and outdoor furniture, making it the most versatile cheap cleaner here.

Strong Contender: Spitfire Heavy-Duty Degreaser

Spitfire, at $17, requires no dilution and put in a consistently strong showing. It finished fourth in the grease test, doing serious damage to the hardened blob, placed fourth on mildew, and took seventh in the cloth test. When only the non-cloth categories count, it lands in second place overall with an average score of 3.

Along with Super Clean, Spitfire earned the best rating in the mildew test, which makes it worth a look if cleaning exterior surfaces is your priority.

Specialist Pick: Oil Eater

Oil Eater, at $14, lives up to its name on grease. It finished a close second in the grease dissolving test and took sixth in the cloth test, with a 3.33 average when the cloth category is excluded. It is marketed as a professional strength concentrate for driveways, engines, and lawnmowers, and one caveat is worth knowing: the bottle says to dilute with water before use but does not clearly state the ratio, so a 50/50 mix was used in testing.

It is the pick for heavy grease buildup specifically, especially around the garage, workshop, or driveway where engine grease is the main enemy.

What About the Rest of the Lineup?

The remaining products each had moments. Simple Green Pro HD placed third in the cloth test and fifth overall on concrete-side performance, WD-40 Specialist took fourth on cloth, LA’s Totally Awesome claimed third on grease, and Purple Power managed third on concrete stains. Krud Kutter, Simple Green Aircraft Cleaner, Dawn dish soap, and Goof Off lagged behind, with Goof Off finishing last in multiple tests, though it should be noted it is designed as a concrete cleaner rather than a general-purpose degreaser.

Overall Buying Advice

If you want one bottle for everything, OxiClean delivered the most consistent results across all four tests. If grease and oil are your main concern and you want the best value, Super Clean at $6 is hard to beat, with Zep a close second for a bit more money. For mildew and exterior cleaning, Super Clean and Spitfire led the pack. Avoid relying on dish soap for serious degreasing; it trailed nearly every dedicated product in every category.

Conclusion

No single degreaser dominated every test, but the winners were clear: OxiClean for overall consistency, Super Clean for value and grease cutting, Zep for oil removal, Spitfire for mildew, and Oil Eater for stubborn grease. Match the product to your most common mess and you will not go wrong with any of the top five.