3 Answers. Mixing new with the old will cause you absolutely no issues. As long as you are using the same weight oil, it will mix up and youd never know it. Continue to change your oil at the specified interval and you should be golden.

Subsequently, question is, can I just top up my engine oil? Your oil level should be somewhere between the two. If your oil level is below the bottom line, or if there isnt any oil on the dipstick at all, you should immediately top up your engine oil.

Subsequently, one may also ask, why do I have to keep adding oil to my car?

A car may be burning oil for a few different reasons. The two most common are because it is bypassing the piston rings, or leaking past the valve seals. Engine oil also circulates around the valves in your engines head. There are seals around each valve to keep the oil from leaking into the combustion chamber.

What happens if you mix different engine oils?

The good news is that mixing different types of oil it will not harm your engine in any way in the short run. Most synthetic and semi-synthetic engine oils are based on regular oil and are compatible. The additives in synthetic oil may have limited or no effect at all when mixed with a regular engine oil.