AT205 Reseal Vs. Blue Devil: Will These Oils Stop Leaking?

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AT205 Reseal and Blue Devil are two of the best products for stopping engine leaking. And you are confused about the choice to make between these products.

An engine starts leaking due to ageing and consistent use. It is quite annoying to pull your vehicle off the road for a minor leak. And, these stop leak oils can save you the expense of hundreds of dollars in a mechanic’s shop.

This article will make your decision easier with all of the specs and detailed comparisons you need to decide between two of the best stop leak oils, AT205 Reseal and Blue Devil.

AT205 Reseal vs. Blue Devil: Comparison chart

The table below provides the most important information about Blue Devil and AT205 reseal. It will help you to compare a summary of their properties.

AT-205 Reseal
Check Price
Blue Devill
Check Price
Customer Rating
CompatibilityHydraulic oil, gear oil, power steering fluids, Synthetic and conventional lubricants.Antifreeze and coolants.
Time to reach efficiency5 hours2 hours
ApplicationTo stop any leaks in the transmission, hydraulic network (excluding the brakes), or power steering system of a vehicle.To recondition any worn-out seals and repair blown head gaskets, freeze plugs, and heater cores.
TechnologyIt works based on the toughness and malleable properties of AT-205 - a compound used in rubber production.It works by bonding to cast, plastic, alloy, aluminum, or any material in the leakage area.
Safe for Gas & Diesel engines

AT205 Reseal vs. Blue Devil: Detailed Comparison

To choose the best between these two sealants, let’s go into further details about their specifications. We will compare them based on the following features.

AT205 Reseal Stop leak

AT205 Reseal Stop leak

Blue Devil Stop leak

Blue Devil Stop leak

How do they work?

ATP Reseal is a watery compound that works by strengthening the chemical bonds in rubber seals and gaskets.  It operates on the same principle used in the manufacture of rubber and flexible materials.

Blue Devil works by binding itself to plastic, rubber, aluminium, or any metal within the leakage region. It is free of any lumps or particulate matter that can clog the engine. Both products can work with diesel and gasoline engines.


Winner: AT205

AT205 works well with gear oil, power steering oil, synthetic oil, and conventional oil. It is chemically inert towards these liquids. Blue devil also mixes well with various types of engine fluids, antifreeze, and fresh coolants. However, it is not quite compatible with synthetic oil. Generally, the Blue devil doesn’t combine well with strong oxidants.

Both products don’t contain any petroleum distillate compounds. Petroleum distillates are known for causing rubber seals to break down. Remember not to place any of the liquids close to flame or heat.


Winner: AT205

AT 205 reseal uses plasticizers to seal leaky gaskets. Plasticizers reduce the stiffness of polymers while increasing their flexibility, ductility, and toughness. This chemical compound also finds its use in the production of films, PVCs, and any material that requires flexibility.

AT205 Reseal Stop leak

AT205 Reseal Stop leak

Blue Devil is a colourless and odourless liquid made from diethylene glycol. Diethylene glycol is a non-corrosive and non-clogging organic compound. It also has dehydration properties that can prevent fluid leakage.


Winner: AT205

AT205 is strikingly easy to use. It works for rubber seals and gaskets within any engine. If you have a leak in your hydraulic system, all you do is pour the reseal product into your hydraulic oil. AT205 will move through the plastic and rubber seals within the system.

If it encounters any hole or space, it blocks them off. However, note that AT205 is capable of dissolving paint. Once you apply this sealant, remember to drive your vehicle for a while to allow proper circulation.

If you don’t do this, the product might attack any paint it comes across and cause it to congest your engine. Also, don’t use AT205 in your brake system.

Blue Devil is capable of reconditioning shrunken seals without damaging any engine component. This formula can be applied to gearboxes, axle seals, pinion seals, and rear differentials. Also, you don’t need to flush your cooling system or remove your thermostat before using it. One downside of Blue Devil is that it cannot repair largely failed gaskets.

Time required to reach efficiency

Winner: Blue Devil

Blue Devil Stop leak

Blue Devil Stop leak

The Blue Devil takes about two hours to work. Within 100 miles of driving, you should see any leaks stopping. On the other hand, ATP AT205 reseal needs 5 hours before it produces any visible results.

Reliability of results

Winner: AT205

Reviews from people who have used both products show that AT205 produces more long-lasting results. Its only major drawback is that it can make your engine produce blue smoke in some cases.

Blue Devil may require days or a few weeks before it can stop extreme leaks. Its effectiveness depends largely on your engine system. It is best to use it on V-6 and inline-four engines.


Winner: AT205

AT205 reseal is the cheaper product. It costs about $10 to $11.99. On the other hand, Blue Devil has an average sale price of $19. The efficiency to cost ratio of AT2015 is higher compared to Blue Devil.


Blue Devil and AT-205 reseal are two great products that can prevent those oil puddles under your vehicle.  After a thorough comparison, AT-205 is the better product. This sealant is compatible with almost any type of engine. It also mixes well with other fluids within a vehicle’s system.

AT205 reseal provides more value compared to its price. Despite the fact that AT205 takes a longer time to circulate through the engine, it promises more permanent results compared to Blue Devil.

Read more: How Fast Can You Drive in 4×4 High & Low?

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