If I understood it right the ‘engine designer’ is only for auditioning the engine sounds.
‘RPM smooth’ (in engine designer) seems to be the same parameter as ‘seek speed’
But what about ‘load smooth’ and ‘load scale’ (in engine designer). Does these parameters exist in Fmod ?
Thomas 
These parameters do not exist. Rather, they’re properties that serve to define the behavior of the engine used to audition events in the engine designer.
The engine designer is just an example of one possible way to build an engine. Most game projects use different models designed specifically to suit their unique needs and requirements. If you are making a game that contains engines, you will have to decide what parameters that engine has and define how they interact as part of your game’s code.
Thanks for the reply. Yeah that was also I expected but just wanted to ensure I hadnt missed it. The 'seeks speed is a really great parameter so it would have been great if the load smooth and scale parameter had been there as well. But I can live with it.