Wake up ford.. Noise canceling should include ICE at low speeds..

[Waldo]

The "growl" is technically "lugging". Lugging is a normal characteristic of all gasoline engines, but is especially noticeable in 4-cylinder engines due to the nature of the balancing. it occurs when the engine is run at low rpm and high load. It's simply the forces going through the crankshaft related to the frequency of their occurrence that produces the loud growling noise. It won't cause damage to the engine, in fact it is usually one of its most efficient operating points. The only reason the engineers don't tune the car to make that growl more often is because of the NVH.

 

The only thing different about lugging in a hybrid is that it's not as easily predictable since the load on the engine isn't always directly related to the torque at the wheels.

[lolder]

Atkinson hybrids ( Fords, Toyotas, Hyundi's, et-al ) operate on the verge of "bucking", a phenomenon once common with stick shift manual transmissions when you have too much throttle for the gear you're in. That edge is the most efficient ICE operating point. The RPM is low, the throttle plate is almost wide open and the spark is as advanced as it can be. The hybrid Atkinson's are almost always operated there. The 2010-12's have a very low level rumble around 50 mph resulting from this "lugging". It means you have one of the most efficient automotive system on the road.

[acdii]

Lugging was the word I was looking for. I hear it most often when the ICE is under load, and cold, once its up to temp and at cruise the ICE makes no noise, in fact its hard to tell if its on ICE or EV at highway speeds. The downside of lugging is the noise canceling produces a lower rumble that can be heard over the ICE.

[HybridDragon]

Thanks for the info and insights (lolder, Waldo, acdii)

 

Ain't hybrid'n just grand?

Edited September 11, 2014 by HybridDragon