The Best Engine Degreaser 2021

Cleaning your engine bay can be fairly difficult due to the layers of dirt, grease, grime and oil that has built up since it was last cleaned. However, with the use of a quality engine degreaser, you can agitate the grease from the surface and wipe it clear.

Best Engine Degreaser

The best engine degreaser is the Gunk 6868 Ultra, which is a powerful water-based formula that cleans and degreases with ease. It also comes in a huge 5 litre container that can be poured into a refillable spray bottle for easier application.

Engine Degreaser Comparison

Engine DegreaserTypeCapacity
Gunk 6868 UltraContainer5 Litre
Autoglym CleanerSpray Bottle1 Litre
STP Professional SeriesAerosol0.5 Litre
Pro-Kleen MultipurposeContainer2 Litre
Meguiar’s Nettoyant MoteurSpray Bottle0.45 Litre
Maddox 40101Spray Bottle0.5 Litre

Attempting to use a car wash shampoo simply won’t be enough for most engine bays as it won’t be able to shift the grease. Degreasing the engine is the best option and the more you do it, the easier it will be to clean.

Below is a list of the best engine degreasers that cut through tough layers of dirt and are completely safe to use.

The Best Engine Degreaser

1. Gunk 6868 Ultra Engine Degreaser

Gunk 6868 Ultra Engine Degreaser
Gunk are a brand that specialize in engine degreasers and their Ultra formula is one of the most rated in the UK. It’s designed to remove grime, grease and stains and comes in a large 5 litre bottle that offers excellent value for the money.

Other features of the Gunk Ultra Degreaser include:

  • Powerful water based formula
  • Both an engine cleaner and degreaser
  • Also suitable for industrial or agricultural machinery
  • Requires a spray bottle or sprayer
  • Easy to use and doesn’t require rinsing
  • Large 5 litre bottle

The Gunk Ultra is the perfect degreaser for cleaning a neglected engine bay with ease and it also offers the best value when compared to the alternatives. For the best results, we strongly recommend getting a new spray bottle and brush to agitate the formula into the grime, grease or stains.
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2. Autoglym Engine Cleaner

Autoglym Engine Cleaner
The Autoglym Engine Cleaner is a ready to use degreaser that can be sprayed onto the engine bay, agitated and wiped off in a matter of minutes. According to the brand, it rapidly dissolves oil, grease, grime and traffic film and it can also be used as an effective wheel cleaner.

Other features of the Autoglym Engine Cleaner include:

  • High quality 1 litre spray bottle
  • Solvent-free, water based formula
  • Environmentally friendly and bio-degradable
  • Easy to apply with a brush
  • Made in the UK

Overall, it’s an easy to use cleaner that powers through grease or grime and can also be diluted for sensitive areas under the bonnet. The formula is also developed by the reputable Autoglym brand for complete peace of mind.
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3. STP Professional Series Engine Degreaser

STP Professional Series Engine Degreaser
The STP Professional Series offers a number of cleaners but the engine degreaser is their most popular product from the series. It’s designed to be a quick and easy solution that penetrates and dissolves heavy dirt and deposits.

Other features of the STP Professional Series include:

  • Suitable for most engines
  • Heavy duty cleaner
  • Aerosol based formula
  • 500 ml bottle
  • Made in the EU

Overall, if you require a powerful engine degreaser that’s affordable and manufactured by a reputable brand, the STP formula is more than ideal. It penetrates and dissolves heavy dirt with ease and it won’t disappoint.
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4. Pro-Kleen Multipurpose Degreaser

Pro-Kleen Multipurpose Degreaser
Pro-Kleen are a brand that produce the best rated snow foam in the UK but they also offer a number of other products such as this degreaser. It comes in a large 2 litre bottle that can be poured into a sprayer for an easier application.

Other features of the Pro-Kleen Heavy Duty Degreaser include:

  • Safe on metal, stainless steel, plastic, rubber and more
  • Cleans, degreases and removes stains
  • Low odour formulation
  • Large 2 litre bottle
  • Made in the UK

The Pro-Kleen Heavy Duty Degreaser does exactly what it says on the packaging and powers through deposits on even the most neglected of engine bays. The only drawback is that its quite expensive when compared to the Gunk alternative.
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5. Meguiar’s Nettoyant Moteur Engine Clean

Meguiar's Nettoyant Moteur Engine Clean
The Nettoyant Moteur formula by Meguiar’s is a high quality engine degreaser that’s designed specifically for engine bays. It’s safe on rubber and plastic and the brand even guarantee that it won’t degrade any fittings or hoses.

Other features of the Meguiar’s Nettoyant Moteur include:

  • 450 ml trigger spray bottle
  • Quickly penetrate all deposits
  • Completely safe to use (and even guaranteed)
  • Fresh smelling fragrance
  • Bio-degradable formulation

The Meguiar’s Nettoyant Moteur is a premium product that’s actually worth spending the extra. The brand also offer a dressing that can be used straight after to provide a long lasting finish and great smelling scent.
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6. Maddox 40101 Engine Bay Cleaner

Maddox 40101 Engine Bay Cleaner
Another popular formula that designed for specifically for car engines is the Maddox 40101 Cleaner. From just a single application, it will dissolve all of the dirt, grease or grime upon the engine and wipes clear with ease.

Other features of the Maddox 40101 Cleaner include:

  • 500 ml spray bottle
  • 100% bio-degradable
  • Suitable for all types of engines
  • Completely safe to use
  • Easy to apply

The Maddox 40101 Cleaner is an excellent all-round formula that’s relatively affordable and highly effective. Whether you are tackling heavy or light dirt, it will leave the treated area like new each and every time.
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Due to the fact that the engine bay is hidden under the bonnet, it often gets neglected whilst washing your car. However, if you are up for the challenge, you can easily tackle the layers of dirt with one of the recommended engine degreasers above. To avoid disappointment, we strongly recommend following the instructions and using a quality detailing brush to agitate the formula.

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