hello again,what oil should i put back in my 1999 s4 t4?10/40 or what???

 

If it's in a moderate climate like the UK, I'd go with a 5W30 fully synthetic. If in a very hot climate then go with the thicker 10W30. If you race it then go with a 10W40 or 20W50. No need for really thick oil in a tight tolerance engine unless running exteme temps.