As someone who can tell when our office server is running less than optimally just by the sound of the fans, I would say that they are distinct, but similar. It's similar to the comparison and contrast that can be heard between a clarinet and a saxophone.

A WBX engine always sounds less like an angry sewing machine than an AC to me. Also, I'd say WBX's seem more smug.

-Jarrett

On Nov 21, 2010, at 9:13 PM, Mark L. Hineline wrote:

> Does a WBX engine sound like an AC engine?
> 
> Mark