I don't know for sure, but I'd be extremely surprised if the
engines are the same.  Engine block yes, state of tune, not
likely I'd say.  An engine for a truck is likely tuned for
torque at low rpms, while the engine for the autobahn
cruiser Audi is more than likely tuned more for top-end
power.  This is just logic-based speculation, but I'd think
finding an actual Audi engine instead might be as simple as
working this all out.