Car engine oil buying guide: Your guide to choosing the right engine oil for your car
Oil keeps your car mechanically sound in more ways than one.
Changing your engine oil can seem a mucky job, but with the right tools, you could save yourself a small fortune.
Garages use oil changes as a way of checking other components on the car for signs of wear and tear.
While in theory, this sounds like a neighbourly and ideal way to keep your motor in tip-top condition, you need to be able to trust that your garage has your best interests at heart, and not its bottom line.
How often do you need an oil change?
Depending on what car you drive, the way you drive, how often you drive and how far determines how frequently you’ll need to change your oil.
Once upon a time, the rule of thumb was every three months or at 3000 miles.
However, modern technology now enables synthetic oils to be more effective, so cars can go anything between 5,000 and 10,000 miles, or six to 12 months.
Car oil isn’t only a lubricant for the engine’s components.
By distributing heat more evenly, the oil helps the engine to cool.
The synthetic formulas these days take the original base of oil, then refine it at a molecular level, creating other substances to act as oil does but without the downsides, e.g. plumes of purple smoke.
Engines are happier with synthetics, since they contain detergents to keep the engine clean and prevent internal rusting.
The viscosity of oil is really important in getting the best out of your oil.
Which oil is better 5w30 or 10w30?
Another question is ‘what do all these weird numbers on oil mean to me and my car?’
Because each engine is designed and refined around a specific oil grade, AKA viscosity, you need to buy the engine oil best for your engine, whether it’s diesel, petrol, modern or classic motoring.
The numbers indicate temperature, the ‘W’ stands for ‘Winter’ and the phrase refers to the viscosity.
When oil is heated, it gets thinner.
When it is cold, it gets more syrupy and makes starting a car in cold weather more difficult.
If an oil has a 0W-20 label, that indicates its viscosity is fluid enough to work in colder weather.
Conversely, 10W-30 indicates that in hotter conditions, the oil will not lose its structure entirely or thin out too much, as it has been designed to withstand higher temperatures.
Older cars generally need a higher viscosity reading.
The straight answer is neither is better.
It’s important to ask what is suitable for your motor.
How much does engine oil cost?
Prices vary but you’re looking at anything from £15 to £60.
An initial oil change will also set you back the costs of the tool.
These won’t break the bank and they will make the job easier:
- Square Drain Plug Key 8mm 3/8”, £4.99 from Halfords- buy here
This key helps loosen off the bolt at the bottom of the engine block for the oil to seep out of
- Bell 6 Litre Oil Drainer Can, £6.99 from Halfords- buy here
There’s a cheaper dish for less than a fiver, but the fact you can lay this one down and then pour it away later will prove useful.
You can consider flushing the engine to clean it, but often that can leave deposits in your system which can build.
Ideally, the engine oil coming out is only a little brown.
Engine oil starts life golden and turns blacker as it gets older. If you are looking shiny black stuff, you’ve left it too long between changes.
Where can I buy engine oil?
Once you’ve referred to your manual to understand the right viscosity for your vehicle’s engine, check out buying options on Amazon, and at Halfords and Tesco.
While Tesco has some great deals on the more common weighted synthetic oils, Halfords provides a tool to help you pick an oil specifically for your car.
If you’re in a bind and need it quickly, Amazon’s Prime fulfilment service can help.
More from Sun Selects motoring
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Found this guide to changing your car engine oil useful? Check out our dedicated Sun Selects motoring section for more motoring advice.
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