Can you use a different oil weight?
Robert Clark
Published Jan 23, 2026
It's best to use the oil viscosity recommended in the owner's manual, but using a slightly thinner or thicker oil (lighter or heavier viscosity) generally poses no long-term harm.
What happens if you use different weight oil?
Can oils of different grades be mixed? 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.Does it matter what weight oil you use?
Using oil that is thicker than recommended may lead to a decrease in fuel economy, a higher load on your engine, and even a shorter life for your engine. Conversely, using thinner, lighter-weight oil than recommended can cause excessive wear and shorter life.Can you switch oil weights?
It is fine to switch between different oil weights, in fact, some people change the weight of oil they use in the summer and winter. It is essential that you stay within the factory recommended specifications in your owner's manual, and heed the advice of professional technicians.What if I accidentally put 10w30 instead of 5w30?
Most oils will mix perfectly, provided they have a similar synthetic. Therefore, there is no problem in mixing 10w30 and 5w30 since one will be topping up. Mixing the viscosity of oils will not have any effect on the engine. 5w30 and 10w30 engine oils have close viscosity, and thus there is no harm in mixing them.Will Thinner Oils Damage Your Engine?
Will the wrong oil damage my engine?
Cause damage to engine lifeThe wrong engine oil can cause engine damage because it does not properly lubricate its components. This will lead to metal-on-metal contact since the moving parts are not being lubricated. Friction quickly follows, causing engine parts to wear.
Will 10w40 hurt a 5w30 engine?
Your vehicle does not use 5W-30 oil. The recommended oil viscosity for your vehicle, according to Kia documentation, is 10W-40. If you drive the vehicle in exceptionally cold weather, well below 32 degrees, you can use 5W-30 oil but even 10W-40 is still perfectly OK to use if outdoor temperatures are below freezing.Can I use 0w40 instead of 5w20?
Re: Can I use 0W-40 high performance synthetic oilThe 0 part means its got the cold-weather viscosity of any 0 weight oil, and will pour even thinner than 5W20 when cold. That's good.
Can I put 10W30 instead of 5w20?
Notwithstanding the recommendations of the car manufacturer, mixing 10w30 and 5w20 will not cause any sort of harm to the engine. However, a few drivers claim that it is safer to combine two multi-grade or straight weight oils, rather than mixing multi-grade with straight weight oils.Can I use 5w30 instead of 5w20?
In general, it is not recommended that you use 5w30 oil (or any other oil weight) in place of 5w20 oil, as the slightest difference in viscosity can potentially damage your engine.Is it OK to put 10W40 in a 10w30?
The short answer is yes. Because both oils are formulated to give the same performance, it will be safe for you to use either oil. Some differences between the two oils include viscosity and base oil.Can you mix 10w30 and 10W40?
Mixing 10W30 with 10W40Some say that mixing them is fine as long as you don't live in freezing weather. Even if you put together synthetic and conventional blends of these motor oils, they show no harm to your vehicle. However, this is true only if you mix in a quart of the other type to your usual engine oil.