We degreased six grimy engine bays to see which cleaner cut the grease without cutting corners, and the Chemical Guys Signature Series Orange Degreaser came out on top. It's the rare product that's strong enough for a filthy bay yet gentle enough that you're not sweating over your plastics and painted metal — the best all-round balance we found, and the one that lives on our shelf.
Degreasing is the heart of any engine bay detail, and the right cleaner makes the degrease-agitate-rinse-dress routine feel easy. Here's the full ranked field, how we tested, and how to pick the right one for your bay.
Top Picks at a Glance
Best Engine Degreasers 2026: The Ranked Field
Best for Most engine bays and general degreasing
- Citrus-based, cuts grease without harsh fumes
- Dilutable — one bottle stretches a long way
- Safe on painted metal, plastic and rubber
- Rinses clean without a greasy residue
Why buy it: The best balance of cutting power and safety we tested — strong enough for a filthy bay, gentle enough that you're not worried about your plastics.
Best for Buyers who want dilutable pro-grade cleaning
- Highly concentrated — dilutes to taste
- Professional-strength on baked-on grime
- Versatile across the whole car, not just the bay
- Excellent cost-per-use once diluted
Why buy it: Dilute it strong for a nasty bay or weak for general use — that flexibility makes one bottle do the work of several, which is why it wins on value.
Best for Owners who want one cleaner for everything
- Non-toxic, biodegradable formula
- Dilutable for engine bays or household use
- Very widely available and inexpensive
- Low-fume and gentle on hands
Why buy it: It's the jack-of-all-trades — dilute it right and it degreases a bay perfectly, then cleans the rest of your garage too, all for very little money.
Best for Neglected, filthy, decades-of-grime bays
- Aggressive solvent-based cut
- Clings to vertical surfaces while it works
- The old-school standard for filthy engines
- Aerosol makes reaching tight spots easy
Why buy it: When a bay is genuinely filthy after years of neglect, nothing here shifts baked-on grease faster — it's the heavy artillery for a first deep clean.
Best for Big jobs on a tight budget
- Strong cut at a rock-bottom price
- Sold in large concentrate jugs
- Dilutes heavily for everyday cleaning
- Widely stocked at hardware stores
Why buy it: Cheapest cost-per-gallon in the test by a mile — dilute it down and a single jug will out-clean bottles costing several times more.
Best for Quick, targeted, ready-to-use spot cleaning
- Ready-to-use, no mixing required
- Foaming action clings where you spray
- Precise trigger for targeted grime
- Trusted, widely available formula
Why buy it: No dilution, no fuss — point, spray, wipe. For quick touch-ups and targeted grease it's the most convenient bottle to keep on the shelf.
Quick Comparison
| Product | Best for | Rating | Price | Buy |
|---|---|---|---|---|
| Chemical Guys Signature Series Orange Degreaser | Best Overall | 4.7 | $$ | Check |
| Meguiar's Super Degreaser | Best Value | 4.6 | $$ | Check |
| Simple Green | Best All-Purpose | 4.6 | $ | Check |
| Gunk Original Engine Degreaser | Best Heavy-Duty | 4.5 | $ | Check |
| Purple Power | Best Budget | 4.5 | $ | Check |
| WD-40 Specialist Degreaser | Best Spray | 4.6 | $$ | Check |
How We Tested
Every product ran the same gauntlet: applied to comparably grimy bays on a cool engine with electronics covered, given an equal dwell, agitated with the same brushes, then rinsed at low pressure. We scored four things — cutting power (how much grease it broke down per pass), safety (how it treated paint, plastic and rubber), value (cost-per-use after dilution), and convenience (mixing, application, rinse-off). Prices are shown in dollar signs because street pricing shifts; the live link has today's number. Solvent-based products were rinsed promptly and kept off sensitive finishes, as they should be.
1. Chemical Guys Signature Series Orange Degreaser — Best Overall
Pros: Great cut-to-safety balance, dilutable, citrus scent instead of harsh fumes, rinses residue-free.
Cons: Not the absolute strongest on decades-old baked grime; mid-pack on price.
The one we'd hand anyone. It's strong enough for a genuinely dirty bay but safe enough on plastics and paint that you're not watching the clock, and it dilutes so a bottle lasts. The complete package.
2. Meguiar's Super Degreaser — Best Value
Pros: Highly concentrated, dilutes strong or weak, pro-grade cut, works across the whole car.
Cons: Full-strength is potent — dilute sensibly; plain bottle, no frills.
The flexibility is the story here. Mix it strong for a nasty bay or weak for general cleaning, and one concentrate replaces several products. That's what earns it best value.
3. Simple Green — Best All-Purpose
Pros: Non-toxic, biodegradable, cheap, cleans far more than engines, low-fume.
Cons: Needs correct dilution for engine grime; less bite than dedicated solvents.
The do-everything pick. Dilute it right and it handles an engine bay, then cleans the rest of your garage. For an owner who wants one honest bottle for everything, it's hard to beat.
4. Gunk Original Engine Degreaser — Best Heavy-Duty
Pros: Aggressive solvent cut, clings while it works, unbeatable on neglected bays.
Cons: Harsh — rinse promptly, keep off sensitive finishes; strong fumes.
The heavy artillery. When a bay hasn't been touched in a decade, nothing here shifts the baked-on grease faster. Reach for it on the first deep clean, then maintain with something milder.
5. Purple Power — Best Budget
Pros: Very cheap per gallon, strong cut, sold in big jugs, widely stocked.
Cons: Strong concentrate needs careful dilution; basic presentation.
The budget hero. Diluted down, a single inexpensive jug out-cleans bottles costing several times more. If you've got a lot of degreasing to do and not much to spend, this is the answer.
6. WD-40 Specialist Degreaser — Best Spray
Pros: Ready to use, foaming cling, precise trigger, no mixing.
Cons: Costs more per ounce than concentrates; less economical for big jobs.
The convenience pick. No dilution, no measuring — point, spray, wipe. For quick touch-ups and targeted grease it's the most grab-and-go bottle in the test.
How to Choose the Right Engine Degreaser
For most bays, the Chemical Guys Orange is the safe, strong, no-drama pick. If you want one concentrate to do the most, the Meguiar's Super Degreaser dilutes to any job. If you want a single non-toxic cleaner for the whole garage, Simple Green is the value all-rounder. If the bay is genuinely filthy, start with heavy-duty Gunk, then maintain with something milder. On a tight budget with lots to clean, Purple Power wins on cost. For quick spot jobs, the ready-to-use WD-40 spray is the most convenient.
Whatever you choose, the rules don't change: cover your electronics, work on a cool engine, don't let product dry, and rinse at low pressure. Then finish with a dressing — because a degreaser cleans, but it's the dressing that makes the bay look finished and keeps grime from coming straight back.
The Verdict
The Chemical Guys Signature Series Orange Degreaser is the one we'd buy again for almost any engine bay — strong enough to cut real grime, safe enough to use without stress, and dilutable enough that one bottle goes a long way. Step up to heavy-duty Gunk for a first deep clean on a neglected bay, or grab Simple Green if you want one cleaner for everything. Check the current price on Amazon and give your engine bay the clean it's been missing.
Affiliate Disclosure
Some links on this page are affiliate links. If you buy through them we may earn a small commission at no extra cost to you. It never changes our verdicts — we only recommend gear we would run on our own cars. Read the full disclosure.