When your vehicle is out of coolant fluid, and there is no option, you can put water into the radiator. Water can work as a coolant. The ideal measurement is to make a 50-50 mixture of coolant and water.

But if your radiator is totally empty, there is no other way but to use water. In this situation, you have to have an idea about how far can you drive with water in radiator.

When to use water?

When to use water

  • If you notice a dashboard warning light coming onto your car, you will know that you are out of coolant. If you don’t have any other option, use water.
  • If you smell a sweet-sharp smell of coolant, that means there is a leak in your cooling system. You can then add water to balance the leaked amount of coolant
  • If you feel the increasing level of the temperature gauge and the car is heating up more than usual, you can add water to calm the temperature down before you go for a check-up of the car.

What is a coolant?

What is a coolant

The cooling system of a car works on balancing the engine temperature within a certain parameter of a vehicle. If the cooling system is compromised, there can be a situation of overheating and damage.

Normally the mixture of antifreeze and water is the main coolant for a car. It absorbs heat and flows from the engine to the radiator and absorbs heat from there. Coolant makes the whole place cool by the air passing through the radiator fins. Not too cold and not too hot; just keeping a balanced temperature is the main motive of a coolant.

How far you can drive without coolant

How far you can drive without coolant

Without any kind of coolant in the radiator, you can drive for one or two miles maximum. An empty radiator is a dangerous thing when you are still driving. After a couple of miles, it starts to damage your engine by getting too much heat.

The risk of using water alone in the radiator

Generally, in a cold climate, this is a risky business. Using water as a coolant is OK for a short interval. However, it must contain some corrosion resistor additive or anti-freeze if you allow it to stay in the engine for a long time.

Running just water in your radiator will create overheating. This excessive heat can damage your car’s radiator as well as cylinder heads and engine block.

Water can evaporate according to the weather. After evaporation, water will set up a layer of non-volatile impurities. Water can freeze too. You have to remember that water may work, but it is not ideal at all.

Again water contains minerals. These are particles of water and leave marks. They will also leave deposits in the radiator. Mineral deposits can create corrosion. Tents and corrosion in the radiator make it less effective and diminish the ability to cool. Repeatedly using water makes the life of a radiator shorter.

How far can you drive with water in radiator?

Far Can You Drive With Water in Radiator

The distance you can manage to pass having water in the radiator depends on time. It does not matter how long or short the distance is; what matters is the time of your driving.

Water loses its working ability as a coolant over time. If you drive a long way within a short period with water, it may fulfil the job. On the other hand, if you drive a short distance but slowly and take too much time, you may have to stop in the middle of the road to use water as a coolant.

Use distilled water for the coolant mission of your vehicle. It is proved that you can pass one week driving your car normally with the water coolant in the radiator. Though it depends on the place you live, what type of vehicle you drive, and the amount of driving but you can do the normal day going works for about a week.

If we estimate the actual distance, you can count on the water for like 3 to 4 miles on average. But it is always the approximate measurement, not the exact one.

Another issue is that if you live in a tropical area and the chance of freezing the engine is low, then you can fill up your radiator with water every three days. In this type of area, mixing any coolant is not necessary. But after 4 days, the radiator will be overheated. So here is a solution that you can normally drive for 3 or 4 days with water.

If you are using distilled water only, then you should keep an eye on the temperature of the engine. As the boiling temperature is 100°C, you must not drive the vehicle hitting that temperature.

There is some advice that you can follow if your water coolant fails to cool down the engine:

  1. If the temperature is above normal, pull over and stop the engine for some time.
  2. Turn off the air conditioner, roll down the window, and cut off all the additional heat. This will make the temperature normal.
  3. When the coolant level is down, fill the engine with water again. Flush the water after repair, then refills. By doing this, you will have a proper proportion of anti-freezing to water.

Things you need to remember

  1. Do not add cold water to a hot engine. It can be the reason for catching fire for the thermal shock. This also can crack the block.
  2. Do not make the water a permanent coolant for your car. Eventually, this can be very expensive.
  3. Pulling down the car and stopping the engine is the best decision to avoid damage. Cooling issues can be solved by replacing the hose, head gasket, thermostat, or radiator at last. It will cost more than 100$, and ultimately an engine change will cost you more than 2000$.
  4. Distilled water is the best for the cooling system.
  5. Water gained from a hose can be contaminated that clog the radiator. So manage distilled water if you can, or dirty water is better than no water.
  6. Never add water to the running radiator. It can create a severe burn as the level of the coolant is not measured in a warm engine.
  7. Do not drive in a place where you can’t find any coolant for a long period. If your radiator has caught corrosion because of using water, do not drive the car.
  8. Never open the radiator if it is hot. Keep checking the coolant level if you suspect anything by turning the radiator cap counterclockwise. It must not be lower than the bottom of the neck of the radiator.

Final Words

How Far Can You Drive With Water in Radiator

Using water with antifreeze by making a coolant is a very normal and constant method. Only straight water may not be the best choice for your radiator for a long time. Now, as you have the idea of how far can you drive with water in radiator, you have to be cautious while driving. I hope this writing will help to clear your confusion and make a safe drive indeed.

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  3. How to Separate Gasoline from Motor Oil?


Hi, my name is Gabrielle. I have been into Automotive Industry for over 15 years. If you’re anything like me, then building, maintaining and improving your Automotive Industry/Projects is all part of the Automotive experience. My goal with this blog is to share my experience with and help you discover new and exciting things about Automotive.