2008 chrysler 300 Antifreeze & Radiator Additives

Antifreeze and Radiator Additives

Canadian weather can be unpredictable. From -40 °C cold snaps to summer highway heat, your vehicle's cooling system is pushed to the limit. Antifreeze works overtime, offering freeze protection in winter, boil-over prevention in summer, and year-round corrosion defense.

But your engine relies on more than just antifreeze. It also requires radiator flush, stop leak, and cooling system additives to keep the cooling system in good health.

Here's what you need to know to help you pick the right antifreeze and radiator additives for your vehicle.

What Is Antifreeze?

Antifreeze is a concentrated liquid additive that is mixed with water to create engine coolant. It lowers the freezing point and raises the boiling point of water in your car's radiator to prevent the engine freezing in the winter and overheating in the summer. You can find antifreeze in two different base formulas:

• Ethylene glycol: This is the most common formula and is highly effective.
• Propylene glycol: This is a less toxic option, but it has higher viscosity and is less thermally efficient.

Quality ethylene glycol-based antifreeze can protect to temperatures as low as -37 °C at a standard 50/50 mix, and even lower at higher concentrations up to approximately 70%, which is critical in extremely cold regions. Propylene glycol-based antifreeze can only protect to -37 °C at 50/50.

What's the Difference Between Antifreeze and Coolant?

While the terms are often used interchangeably, antifreeze is a concentrated chemical additive. Coolant is created when the concentrate is mixed with water so it can circulate through the engine. Technically, antifreeze becomes coolant once it's diluted. You can purchase pre-mixed coolant or concentrate that requires dilution before use.

Antifreeze Types: IAT, OAT, HOAT, PHOAT, and NOAT/NMOAT

Consider which type of antifreeze may be best for your vehicle.

IAT (Inorganic Acid Technology)

IAT antifreeze is typically green and best suited for older North American vehicles (generally pre-1998), as well as vehicles with copper radiators and heater cores. It has a service life of around two years or 48,000 km.

OAT (Organic Acid Technology)

OAT is usually orange, red, yellow, or purple and works best in vehicles manufactured post-1998. It has a longer service life than IAT: up to five years or 240,000 km, whichever comes first. OAT is commonly used in General Motors and Saab vehicles, among others.

HOAT (Hybrid Organic Acid Technology)

HOAT combines IAT and OAT benefits and is often required by European and Asian vehicle manufacturers. Keep an eye out for vehicle-specific HOAT subcategories before purchasing. This type of antifreeze should be replaced maximum every 240,000 km or five years, whichever comes first.

PHOAT (Phosphate Hybrid Organic Acid Technology)

PHOAT is used by some Asian vehicle manufacturers and can last up to five years or 240,000 km.

Always check your owner's manual or use the vehicle selector on napacanada.com to confirm the right antifreeze for your vehicle. Mixing incompatible coolant types can damage your cooling system.

Concentrate vs. Pre-Mixed Formulas

Concentrates must be diluted with deionized water (not just tap water). A 50/50 mix is the most common, but some formulas require up to 70/30 antifreeze-to-water. (Note that a higher concentration doesn't mean improved protection.)

In comparison, pre-mixed coolant is ready to use straight from the bottle, making it extremely convenient for top-ups. Adding undiluted concentrate directly to a radiator can clog the cooling system over time.

Radiator Flush Products

Always flush your radiator before a coolant change, or when coolant appears rusty, sludgy, or discoloured. A flush removes rust deposits, scale, and greasy buildup that can reduce circulation efficiency. Proper circulation is a must year-round, because it promotes better heater performance in the winter and better cooling in the summer.

To make sure your radiator is clean, use a specialized radiator flush product and cleaning kit, then refill with fresh antifreeze.

Radiator Additives: Stop Leak and Cooling System Treatments

Stop Leak

Stop leak helps seal small gaps in radiators, heater cores, gaskets, and freeze plugs from the inside. It is compatible with all antifreeze types and colours, but stop leak is a temporary fix for minor leaks. Persistent or larger leaks will require professional repair.

Cooling System Treatments

Cooling system treatments provide ongoing protection between radiator flushes by stopping rust and scale buildup, as well as lubricating water pump seals to prevent cracks. These treatments extend coolant service life and are especially beneficial for heavy-duty or diesel engines under heavy demand.

Gas Line Antifreeze

This product prevents your fuel lines from freezing, making it especially helpful in the coldest winter months.

Air Antifreeze

Heavy-duty vehicles with air brakes benefit from air antifreeze, usually referred to as either air brake antifreeze or air line antifreeze. It prevents moisture in air brake systems from freezing.

When to Check and Replace Your Antifreeze

Set a reminder to check your coolant level every six months, ideally before winter and before summer, the seasons where temperature stresses your engine the most. Keep an eye out for low levels, discolouration (brown or sludgy), a sweet smell, or puddles under the vehicle that match the colour of your antifreeze.

Remember that replacement intervals vary by product type:

• IAT: around two years or 48,000 km
• OAT: up to five years or 240,000 km
• HOAT: max. every five years or 240,000 km
• PHOAT: up to five years or 240,000 km

To get the most accurate reading, let the engine cool completely before opening the reservoir cap and checking your antifreeze levels.

After you've replaced your antifreeze, dispose of it properly: don't pour it down the drain.

Canada's climate can deliver wild temperature fluctuations. But you can keep your engine running its best no matter what season thanks to antifreeze, radiator flush, stop leak, and cooling system additives from trusted brands. Browse our complete cooling system fluid selection online at NAPA Canada or get support from our automotive experts in store at your local NAPA Auto Parts.