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.
On a car made in the last several decades? Not shit. They all have knock sensors to retard timing to a safe level if the octane is lower than what’s needed at that moment (depending on ambient/intake temps, load, etc).
Will a car lose a few horsepower? Possibly. Hardly makes a difference for most people on their commute.