Should You Top Up or Change Your Engine Oil?

When the engine oil light switches itself on, that’s usually a sign that you need to check the oil level of your car. Most drivers, upon doing this, simply top up their engine oil and carry on using their vehicle as normal. However, sometimes it might be alerting you that your oil is contaminated or not fit for purpose. In these circumstances, it is recommended that you change the oil entirely rather than simply top it up.

In this article, we’re going to discuss the difference between an oil change and an oil top-up and explain which process might be best for you.

What’s the difference between topping up and changing engine oil?

Topping off your engine oil is exactly what it sounds like. When your oil levels fall below the recommended level for optimal performance, you add new oil to what’s already in the engine to get it back up to the desired level. The old oil remains in the engine, including any debris or contaminants that might have built up over the years, and these could end up mixing with the new oil and affecting your engine.

An engine oil change involves draining all the oil out of your engine and flushing the system to remove any unwanted contaminants. The oil filter is also discarded and replaced before filling the engine with fresh, clean oil.

What are the benefits of changing engine oil?

An engine oil change brings many benefits to you and your car. With the impurities removed from the engine, you get a more efficient driving experience, including better mileage. Since contaminants in the oil can damage the engine’s moving parts, regular oil changes can extend the life of your engine. Old oil is notoriously bad for the environment, resulting in unpleasant and toxic gas being released, something that could also cause your vehicle to fail its emissions test.

engine oil bottles

How can you tell if your engine oil needs topping up or changing?

Deciding between an engine oil top-up and an engine oil change is largely a matter of oil quality. Let your engine cool down, insert a clean dipstick, and wait for a brief moment before retrieving it. You will be able to tell from the level the oil reaches on the dipstick how much oil is left in the engine and whether you need to add more.

You should also check the smell and colour of the oil. If the oil smells like fuel or has a sweet smell, it is likely contaminated and needs to be replaced. Likewise, the colour of the oil should fall somewhere between a shade of amber and jet black. If your oil is distinctly different (red, green, and pink are common discolourations), that’s another sign that you should change your oil.

How do you top up your engine oil?

First of all, you need to ensure that you have the right oil for your car. Different makes and models of engines require particular qualities and viscosities from their oil. Remove the oil filler cap and begin to pour in the oil, a small amount at a time. Give the oil a chance to settle in the sump (around a minute should do) before checking the oil level again with your dipstick. 

Repeat this process until the oil is back up to an acceptable level. Be sure to do this in small stages, as overfilling the engine can cause problems of its own. Once the engine oil has been topped off, screw the oil filler cap back into position, and you should be ready to go.

How do you change your engine oil?

Compared to topping off your engine oil, changing the oil is much more complicated and a task best performed by a trained mechanic. If you really want to attempt it yourself, this is how you go about it:

  • Lift your car off the floor, high enough to work underneath it, using a hoist, floor jack, ramps, or a combination of the three.
  • Unscrew the cover of the oil pan and place a large receptacle (such as a 5-gallon bucket) underneath it.
  • Loosen and remove the drain plug, and let the oil drain into the bucket.
  • Locate and remove the old oil filter, including the gasket.
  • Once all the oil has been drained, replace and tighten the drain plug, and install your new oil filter.
  • Finally, fill the engine with oil using a funnel, checking the oil level with a dipstick as you go.

Should I top up or change my engine oil? Final Thoughts

Both topping up and changing your engine oil can be messy business, particularly if it’s not a process that you’re familiar with. Here at TCM Automotive, we provide an engine oil top-up or replacement as part of our extensive car servicing package. If you live in the Hampshire area, make an appointment with the experienced mechanics at our Portsmouth service centre today. Call us on 07581 033 606 to see what we can do for you.