You only need to change the oil once a year or 10,000 miles. I see Smarts rolling 100K miles and they stuck to the recommended service intervals. Even our AMG brand uses the same interval...Normally get the oil on my 2017 smart changed at 7500 mile. Have only driven 4000 mi since the last oil change on November 2018. The oil change reminder message came on Nov 1 2019 even though it has only been 4000 miles. I'm thinking that the computer kicks in after one year without an oil change??