1st order temporal & 2nd order spatial
 

I'm using 1st order temporal & 2nd order spatial discretization schemes to solve a low speed reacting laminar flow. someone told me that using 1st order time integration means converting the overall accuracy of the solution down to 1st order, irrespective of the 2nd order spatial discretization.

is this true? I thought by keeping my time step size small, I eliminate this error (???).