Lexus nx oil change concern - does this oil look new or old?
#16
Intermediate
You could also look at it this way...If the oil is darker than when it was initially poured into the engine, this shows that the oil is doing it's job of removing the contaminants, etc., from the engine!
#17
Since I own both a naturally-aspirated and turbo-GDI engine vehicles, I can compare oil samples to see which is darker. Here are the un-scientific results:
The NA-engine oil appears darker, despite having accumulated fewer miles since the last oil change. Both samples appear lighter than the original post sample. Perhaps the water-cooled turbo mitigates the higher thermal oil oil stress. It is also possible our non-aggressive driving style and low highway miles (less than 20%) result in the turbo hardly ever operating.
This may not be a valid comparison because the sample viscosity values are different (20 versus 30). To achieve a thicker oil, the "recipe" might be different and the 5W-30 oil might have been darker when new.
Note that, since the onset of the pandemic, both vehicles have been driven only ~3000 miles per year. So the annual oil change interval has been ~3000 miles, not 10,000.
The NA-engine oil appears darker, despite having accumulated fewer miles since the last oil change. Both samples appear lighter than the original post sample. Perhaps the water-cooled turbo mitigates the higher thermal oil oil stress. It is also possible our non-aggressive driving style and low highway miles (less than 20%) result in the turbo hardly ever operating.
This may not be a valid comparison because the sample viscosity values are different (20 versus 30). To achieve a thicker oil, the "recipe" might be different and the 5W-30 oil might have been darker when new.
Note that, since the onset of the pandemic, both vehicles have been driven only ~3000 miles per year. So the annual oil change interval has been ~3000 miles, not 10,000.
#18
Lexus Test Driver
Oil turns darker in diesel engines even faster than turbo engines, diesel engines run hotter than turbo engine and turbo engines runs hotter than conventional gas engines. Engine oil turns dark when it gets hot or when it capture contaminates. A carbon up engine could also cause oil to turn dark very fast, that is why it is good to get the oil tested.
#19
Driver School Candidate
Mine same
I do my own oil changes using Mobil 1 extended performance oil. In less than 400 kilometres of driving, the oil is medium dark. I’ve never owned a turbo vehicle before but 6 naturally aspirated Toyotas and the oils in my past vehicles stayed light amber for at least 2,000 kms. I asked the dealership and they said it’s normal as long as it doesn’t turn really dark that quickly. After the initial medium dark colour after 400 kms, it didn’t really get any darker by the next oil change interval.
#21
Driver
Thread Starter
So I ended up going back to the dealer and they offered to change the oil again for me for peace of mind. The oil looks exactly the same so I guess this is how the oil is suppose to look
#22
Intermediate
#23
Driver
Thread Starter
#24
Out of curiosity... I checked my 2014 GS and 2019 NX and here is what I show... The top image is the NX with 30.5k miles on it and about 750 miles since last change. The bottom image is the GS with 81.1k miles on it and about 1200 miles since last change. Both are city driving and about three months on the oil changes.
#25
Here’s my latest oil change photo montage. 1st photo shows pre change after 6 months/8,000km, 2nd shows immediately after the change in the parking lot at the dealership. 3rd shows immediately after a 10 minute 5km drive. As expected, the only time you’ll see nice clear oil is immediately after the change (2nd photo), then the darkening starts.
#26
In 2016 I purchased a 2015 RX350 for myself and a 2016 NX200t for the wife. For the first 2 years the Lexus dealership changed our oil every 10,000 miles. After that i started doing my own oil changes like i have for years. I run Mobil1 0w20 and use the OEM filter or a WIX only in both cars but started changing at 8,000 miles because I feel better about this milage. Anyway, comparing the color of both cars, The Nx200t with the Turbo 4cy was a lot darker than the RX350 V-6. The next time I changed the NX200t at 6,000 miles. Now I'm changing the NX at 5,000 and the oil color matches the RX350 at 8,000. I'm 70 now and have done almost all of the work on cars that I have owned and have always believed that oil is cheaper than a new engine. For me this is the last 4cy turbo that I will ever own. Also, didn't like the extra 40,000-mile sparkplug change. Hard for an old dog to change.
#27
Intermediate
Also, after learning/reading a little more in my old age, I've decided to use my torque wrench a bit more frequently as an added precaution. So, for the first time in XXXX years, I am now torquing my spark plugs !
As for the oil change, I do mine every 5k (DIY) with Mobil-1 0W-20 and an OEM filter. I let the oil drain out for at least 20 minutes before putting the new filter and drain plug back on. I also put in about 1/2qt of oil into the oil filter canister before installing it (deducted from the full amount required for an oil/filter change).
The following users liked this post:
chas410 (12-15-22)
#28
Intermediate
#30
Your correct the plugs are not hard to change just something else to mess with. I did buy a special spark plug socket with an extension attached and won't come off. I never use anti-seize on NGK plugs. Also torque almost everything I work on. Like you I also always preload my oil filters.