Nissan is about the same times for me..
In the other league we had 1 hour races with more fuel consumption and tireware, makes it more fun when you have to make a strategy regarding pitstops and so..
20:15 uk time is 21:15 Sweden time right?
What SRou has done in the past with GTR2 is Sprint racing (30-40 minute races) in the week and Endurance racing on a Sunday (60-120 minute races). I don't know if that's the longer term plan for AC should there be demand for it, but that would be in line as to how its worked in the past here.
AC is still lacking a lot of help for server administrators that would help make it less of a hassle to run leagues properly so it may be that these other series are added in line with AC versions that work properly. ;-)
I find the pit stops in AC ridiculous still tbh. They work, but barely and they are poorly implemented.