4.7 is likely under-rated too, considering magazines use a 1 foot rollout, and manufacturers do not. The manufacturers tend to report performance based on shit gas.
i.e. reporting 4.7 is likely a 4.5 when you factor in rollout…and is likely done on 91 not 93-94, which would maybe produce a 4.4. They also sandbag it a bit too just to be safe knowing that nobody cares about manufacturer reported stats, so no point opening themselves up to a lawsuit.
I will be shocked if the 0-60 time is any more than 4.3 seconds. Probably 4.0.
Don’t forget the A8 uses lots of aluminium. That engine is the S6/7 engine…and those cars are hitting 60 mph in 3.7-3.8 seconds with curb weights of 4200 lbs. The A8 is only about 400 lbs heavier