Can anyone tell me what type of oil my A3 1.8T sport should use, I bought a litre of oil from my local Audi dealer on Saturday and the oil the sold me is a 10W 40 grade semi-synthetic costing about 4.00, seemed a bit cheap to me and also I would have expected the car to run on fully synthetic oil, the car has had a mixture of standard and extended life sevices done but the last couple where standard services, any help much appreciated ??????????