Old man at the Benz dealership says he’s been driving the same car for a long time and usually only puts in 87 octane in sprinkled with 91 every few times. What problems could this cause? Do I have to put in 91?
Disclaimer: I’ve owned (paid off) the car for 6 years and do put in 91, but trying to cut costs.
Worse gas mileage. I calculate miles per dollar when my car requires anything besides 87. Harley recommends 91, I usually use 92 due to availability.