Loud droning noise when accelerating

bad exhaust system?

 

ditto on exhaust leak

Paul

 

If it changes pitch with the engine speed (which can stay the same as the vehicle accelerates due to the CVT-like-drivetrain), I agree, it's mostly likely your exhaust, this is where I would look. Pretty easy to jack up the car and then examine the exhaust system using a flashlight to see if there are holes.

If the droning changes speed with the vehicle speed but not the engine speed, most likely cause is wheel bearings.

Less likely is a bad motor mount. I've had a car where you could hear and feel the vibrations of the engine on acceleration when the motor mount failed (metal-on-metal inside the motor mount). This you can tell because it happens more at the start of accelerating, and especially when accelerating rapidly from a stop due to more g forces on the engine. The sound goes away or diminishes a fair amount as the vehicle picks up speed.

 

How does your battery level look when this is happening?