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.
Ouch, too much boost is definitely trouble. The primary goal of the performance tuning process is slowly raising boost to within the limits of the engine durability, fuel system capacity, turbocharger limits, and fuel octane. Uncontrolled over boost can crack pistons, blow rods through blocks, and generally never end well.