diff --git a/torch2trt/calibration.py b/torch2trt/calibration.py
index 7506ea4e..b09b7193 100644
--- a/torch2trt/calibration.py
+++ b/torch2trt/calibration.py
@@ -51,7 +51,7 @@ def get_batch(self, *args, **kwargs):
                     buffer[i].copy_(tensor)
                 
                 self.count += 1
-                
+
             return [int(buf.data_ptr()) for buf in self.buffers]
         else:
             return []
diff --git a/torch2trt/torch2trt.py b/torch2trt/torch2trt.py
index e2aba5d4..58d84672 100644
--- a/torch2trt/torch2trt.py
+++ b/torch2trt/torch2trt.py
@@ -501,10 +501,12 @@ def torch2trt(module,
               strict_type_constraints=False,
               keep_network=True,
               int8_mode=False,
+              int8_calibrator=None,
               int8_calib_dataset=None,
               int8_calib_algorithm=DEFAULT_CALIBRATION_ALGORITHM,
               int8_calib_batch_size=1,
               use_onnx=False,
+              onnx_file_path=None,
               **kwargs):
 
     # capture arguments to provide to context
@@ -518,7 +520,7 @@ def torch2trt(module,
     logger = trt.Logger(log_level)
     builder = trt.Builder(logger)
     config = builder.create_builder_config()
-    
+
     if isinstance(inputs, list):
         inputs = tuple(inputs)
     if not isinstance(inputs, tuple):
@@ -535,14 +537,24 @@ def torch2trt(module,
         output_names = default_output_names(len(outputs))
 
     if use_onnx:
-
-        f = io.BytesIO()
-        torch.onnx.export(module, inputs, f, input_names=input_names, output_names=output_names)
-        f.seek(0)
-        onnx_bytes = f.read()
         network = builder.create_network(1 << int(trt.NetworkDefinitionCreationFlag.EXPLICIT_BATCH))
         parser = trt.OnnxParser(network, logger)
-        parser.parse(onnx_bytes)
+        if onnx_file_path is not None:
+            print('\tBeginning ONNX file parsing.. path = ', onnx_file_path)
+            with open(onnx_file_path, 'rb') as onnx_model_file:
+                onnx_model = onnx_model_file.read()
+            if not parser.parse(onnx_model):
+                raise RuntimeError("Onnx model parsing from {} failed. Error: {}".format(onnx_model_file, parser.get_error(0).desc()))
+            else:
+                parser.parse(onnx_model)
+                print('\tEND ONNX file parsing.')
+        else:
+            f = io.BytesIO()
+            torch.onnx.export(module, inputs, f, input_names=input_names, output_names=output_names, opset_version=13)
+            f.seek(0)
+            onnx_bytes = f.read()
+            # parser = trt.OnnxParser(network, logger)
+            parser.parse(onnx_bytes)
 
     else:
         network = builder.create_network()
@@ -567,15 +579,19 @@ def torch2trt(module,
         if int8_calib_dataset is None:
             int8_calib_dataset = TensorBatchDataset(inputs_in)
         
+        config.set_flag(trt.BuilderFlag.FP16)
         config.set_flag(trt.BuilderFlag.INT8)
-        
+
         #Making sure not to run calibration with QAT mode on 
         if not 'qat_mode' in kwargs:
         # @TODO(jwelsh):  Should we set batch_size=max_batch_size?  Need to investigate memory consumption
-            calibrator = DatasetCalibrator(
-                inputs, int8_calib_dataset, batch_size=int8_calib_batch_size, algorithm=int8_calib_algorithm
-            )
-            config.int8_calibrator = calibrator
+            if int8_calibrator is None:
+                calibrator = DatasetCalibrator(
+                    inputs, int8_calib_dataset, batch_size=int8_calib_batch_size, algorithm=int8_calib_algorithm
+                )
+                config.int8_calibrator = calibrator
+            else:
+                config.int8_calibrator = int8_calibrator
         
     engine = builder.build_engine(network, config)