Mercedes Benz recently updated S Class with more features and technologies. Motor1 spotted a Mercedes S Class test mule which looks similar to current model. But the test mule has extended wheel arches which is a sign that under the current body Mercedes might be testing mechanical parts of next generation S Class. Mercedes already confirmed that new S Class will arrive only by the end of this decade. We know that next generation model will lighter thanks to use of aluminum and carbon fibre. The new S Class will also get advanced autonomous features also. We can expect Mercedes to introduce new S Class by 2020. 

source : Motor1