diff --git a/cads_adaptors/adaptors/cadsobs/adaptor.py b/cads_adaptors/adaptors/cadsobs/adaptor.py
index 89a871eb..fe94948c 100644
--- a/cads_adaptors/adaptors/cadsobs/adaptor.py
+++ b/cads_adaptors/adaptors/cadsobs/adaptor.py
@@ -11,6 +11,7 @@ class ObservationsAdaptor(AbstractCdsAdaptor):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.download_format = "as_source"
+        self.mapped_request: Request = dict()
 
     def retrieve(self, request):
         try:
diff --git a/cads_adaptors/adaptors/cds.py b/cads_adaptors/adaptors/cds.py
index 152989de..034a2c97 100644
--- a/cads_adaptors/adaptors/cds.py
+++ b/cads_adaptors/adaptors/cds.py
@@ -37,7 +37,6 @@ def __init__(
 
         # The following attributes are updated during the retireve method
         self.input_request: Request = dict()
-        self.mapped_request: Request = dict()
         self.download_format: str = "zip"
         self.receipt: bool = False
         self.schemas: list[dict[str, Any]] = config.pop("schemas", [])
@@ -313,12 +312,6 @@ def normalise_request(self, request: Request) -> Request:
                 random_key = str(randint(0, 2**128))
                 request["__part_of_request_under_embargo"] = random_key
 
-        # At this point, the self.mapped_requests could be used to create a requesthash
-
-        # For backwards compatibility, we set self.mapped_request to the first request, and assume
-        #  it is the only one. Adaptors should be updated to use self.mapped_requests instead.
-        self.mapped_request = self.mapped_requests[0]
-
         self.context.info(
             f"Request mapped to (collection_id={self.collection_id}):\n{self.mapped_requests}"
         )
diff --git a/cads_adaptors/adaptors/mars.py b/cads_adaptors/adaptors/mars.py
index 144ccee9..2554fe02 100644
--- a/cads_adaptors/adaptors/mars.py
+++ b/cads_adaptors/adaptors/mars.py
@@ -168,33 +168,33 @@ def pre_mapping_modifications(self, request: dict[str, Any]) -> dict[str, Any]:
         request = super().pre_mapping_modifications(request)
 
         # TODO: Remove legacy syntax all together
-        data_format = request.pop("format", "grib")
-        data_format = request.pop("data_format", data_format)
+        data_format = request.get("format", "grib")
+        data_format = request.get("data_format", data_format)
 
         # Account from some horribleness from the legacy system:
         if data_format.lower() in ["netcdf.zip", "netcdf_zip", "netcdf4.zip"]:
-            self.data_format = "netcdf"
+            data_format = "netcdf"
             request.setdefault("download_format", "zip")
 
+        request.setdefault("data_format", adaptor_tools.handle_data_format(data_format))
+
         default_download_format = "as_source"
         download_format = request.pop("download_format", default_download_format)
         self.set_download_format(
             download_format, default_download_format=default_download_format
         )
 
-        # Apply any mapping
-        mapped_formats = self.apply_mapping({"data_format": data_format})
-        # TODO: Add this extra mapping to apply_mapping?
-        self.data_format = adaptor_tools.handle_data_format(
-            mapped_formats["data_format"]
-        )
-
         return request
 
     def retrieve_list_of_results(self, request: dict[str, Any]) -> list[str]:
         # Call normalise_request to set self.mapped_requests
         request = self.normalise_request(request)
 
+        data_format = request.get("data_format", "grib")
+        for req in self.mapped_requests:
+            data_format = req.pop("data_format") or data_format
+        self.data_format = data_format
+
         result = execute_mars(
             self.mapped_requests,
             context=self.context,
diff --git a/cads_adaptors/adaptors/multi.py b/cads_adaptors/adaptors/multi.py
index 9feee442..232d29d8 100644
--- a/cads_adaptors/adaptors/multi.py
+++ b/cads_adaptors/adaptors/multi.py
@@ -8,6 +8,10 @@
 
 
 class MultiAdaptor(AbstractCdsAdaptor):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.mapped_request: Request = dict()
+
     @property
     def extract_subrequest_kws(self) -> list[str]:
         # extract keywords from a function signature