First what is YOUR year of YOUR Chevy Impala?
Second, does your transmission have "PRNDM" on the shifter (like the image below)?
The "M" stands for Manual Mode. On the top of your shifter you should see a "+" / "-" ... When your on bad roads, especially in a front wheel drive car, this mode helps me out greatly when I need to slow my car down faster (for example) during Black Ice or other bad road conditions.
Most newer Chevy Impalas have the "V-Tech" engine / transmission installed within the cars today. (In dicated by the "M" on the dashboard.)
The V-Tech engines are rock solid engines. I was driving one day & applying the brakes I knocked my shifter into reverse!



I thought I destroyed my engine because I am going forward & I look at my dask board an I see this "R" blinking red on my dashboard (the red) indicating I was in reverse & blinking meaning I was going forward. As I was pressing on the gas I realized I was not going anywhere (I thought I lost power), but unbeknownst at that time the computer was smart enough to NOT engage the transmission & I was able to safely put it back into Drive & all was fine.

But I use the Manual Mode a lot more than I thought I would...
I also bought a 2014 Chevy Impala with low milage on the engine back in 2016. It had right around 38k on the engine, like yours. The first oil change I did was I went to Walmart & purchased either Mobile One's 5w-20 Full Synthetic oil or other 5w-20 (0w-20 Full Synthetic CAN be used as an alternative depending upon the climate you have your car in) Full Synthetic oil that is on sale.
Full Synthetic oil helps better with the wear & tear on the engine... HOWEVER! Once you start with full synthetic oil you need to continue with full synthetic oil.
My car has 160k on it now and is 6 years old. I have been doing the regular maintenance on it since I got it and had no problems so far with my Chevy.
Every ~5,000 Miles : Change Synthetic 5W-20 oil
Every 50,000 Miles : Change Transmission Oil
Every 100,000 Miles: Change Spark Plugs
Every 50,000 Miles : Change air & cabin filters
This is what I do & I have yet to see an issue.
One more thing that I additionally do is that I only use one two additives ever in my car the first is Lucas Oil's 5,000 mile fuel injector cleaner & when warrented a bottle of STP Anti-freeze gas treatment (to remove excess water from the gas tank) so that my car gets a little better milage per gallon of gas.
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