FAQs

What does oil do?

Whether it's in the engine or around the gears, oil is designed to separate moving metal parts. When metal moves against metal, it creates heat, friction and the metal parts can wear each other away. The right, good quality oil protects the metal parts, preventing premature wear. It will also improve fuel economy.

Top of Page Which oil do I need for my car?

Getting the right oil for your car is vital, in the past it used to be about the viscosity (i.e. thickness over a given temperature range), and later about 'types' of oil - mineral, or fully synthetic, for example. But things have become more complicated than that. Nowadays, you need to get not only the right viscosity, but also match to the correct 'industry standard' and vehicle manufacturer specifications. It is complicated and you have to get it right as you can cause serious damage to your engine by selecting the wrong oil. You can use the Comma oil guide by clicking on the motorist home page to find exactly the right product for your vehicle.

Top of Page Can I just put water in my cooling system/radiator?

No! Absolutely not. Your radiator and cooling system are likely of a number of different, expensive metals. Water alone can cause corrosion of these metal parts, which can result in very costly repair bills.  You might think adding water is sufficient if your fluid level is low, but it's actually a false economy especially given that a good quality antifreeze/coolant can last up to 5 years. Click on the motorist home page and use our online application guide to find which antifreeze/coolant is recommended for your vehicle.

Top of Page Why do I need antifreeze/coolant?

When it's running, your engine creates a lot of heat. It is crucial that the heat is transferred away from the engine as quickly as possible, otherwise it will overheat. A good quality antifreeze/coolant runs round the engine, capturing the heat. It returns to the radiator - often located near the front of the engine - where the heat is then lost to the atmosphere.  If you try to get away with just water you may find your system will boil on a hot summer's day - a major cause of breakdowns.

In the Winter, when ambient temperatures plunges below zero, the liquid in the car's cooling system needs to be protected from freezing. Get this wrong and you could actually split your engine block.  A good quality antifreeze/coolant should withstand temperatures as low as -36°C.

Top of Page What's the difference between antifreeze and coolant?

Nothing! People used to think that antifreeze was something you put in the engine in Winter - to prevent freezing. And that coolant was something else - possibly water - that you needed in the Summer. The truth is that whether you call it antifreeze or coolant, it is the same liquid chemical product.

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