diff --git a/selfdrive/car/tests/test_fw_fingerprint.py b/selfdrive/car/tests/test_fw_fingerprint.py
index 257a40f6a3..36619f4cde 100755
--- a/selfdrive/car/tests/test_fw_fingerprint.py
+++ b/selfdrive/car/tests/test_fw_fingerprint.py
@@ -5,10 +5,9 @@ import time
 import unittest
 from collections import defaultdict
 from parameterized import parameterized
-import threading
+from unittest import mock
 
 from cereal import car
-from openpilot.common.params import Params
 from openpilot.selfdrive.car.car_helpers import interfaces
 from openpilot.selfdrive.car.fingerprints import FW_VERSIONS
 from openpilot.selfdrive.car.fw_versions import FW_QUERY_CONFIGS, FUZZY_EXCLUDE_ECUS, VERSIONS, build_fw_dict, \
@@ -176,29 +175,36 @@ class TestFwFingerprint(unittest.TestCase):
 
 class TestFwFingerprintTiming(unittest.TestCase):
   N: int = 5
-  TOL: float = 0.12
-
-  @staticmethod
-  def _run_thread(thread: threading.Thread) -> float:
-    params = Params()
-    params.put_bool("ObdMultiplexingEnabled", True)
-    thread.start()
-    t = time.perf_counter()
-    while thread.is_alive():
-      time.sleep(0.02)
-      if not params.get_bool("ObdMultiplexingChanged"):
-        params.put_bool("ObdMultiplexingChanged", True)
-    return time.perf_counter() - t
+  TOL: float = 0.05
+
+  # for patched functions
+  current_obd_multiplexing: bool
+  total_time: float
+
+  def fake_set_obd_multiplexing(self, _, obd_multiplexing):
+    """The 10Hz blocking params loop adds on average 50ms to the query time for each OBD multiplexing change"""
+    if obd_multiplexing != self.current_obd_multiplexing:
+      self.current_obd_multiplexing = obd_multiplexing
+      self.total_time += 0.1 / 2
+
+  def fake_get_data(self, timeout):
+    self.total_time += timeout
+    return {}
 
   def _benchmark_brand(self, brand, num_pandas):
     fake_socket = FakeSocket()
-    brand_time = 0
-    for _ in range(self.N):
-      thread = threading.Thread(target=get_fw_versions, args=(fake_socket, fake_socket, brand),
-                                kwargs=dict(num_pandas=num_pandas))
-      brand_time += self._run_thread(thread)
+    self.total_time = 0
+    with (mock.patch("openpilot.selfdrive.car.fw_versions.set_obd_multiplexing", self.fake_set_obd_multiplexing),
+          mock.patch("openpilot.selfdrive.car.isotp_parallel_query.IsoTpParallelQuery.get_data", self.fake_get_data)):
+      for _ in range(self.N):
+        # Treat each brand as the most likely (aka, the first) brand with OBD multiplexing initially on
+        self.current_obd_multiplexing = True
 
-    return brand_time / self.N
+        t = time.perf_counter()
+        get_fw_versions(fake_socket, fake_socket, brand, num_pandas=num_pandas)
+        self.total_time += time.perf_counter() - t
+
+    return self.total_time / self.N
 
   def _assert_timing(self, avg_time, ref_time):
     self.assertLess(avg_time, ref_time + self.TOL)
@@ -207,44 +213,49 @@ class TestFwFingerprintTiming(unittest.TestCase):
   def test_startup_timing(self):
     # Tests worse-case VIN query time and typical present ECU query time
     vin_ref_time = 1.0
-    present_ecu_ref_time = 0.8
+    present_ecu_ref_time = 0.75
+
+    def fake_get_ecu_addrs(*_, timeout):
+      self.total_time += timeout
+      return set()
 
     fake_socket = FakeSocket()
-    present_ecu_time = 0.0
-    for _ in range(self.N):
-      thread = threading.Thread(target=get_present_ecus, args=(fake_socket, fake_socket),
-                                kwargs=dict(num_pandas=2))
-      present_ecu_time += self._run_thread(thread)
-    self._assert_timing(present_ecu_time / self.N, present_ecu_ref_time)
-    print(f'get_present_ecus, query time={present_ecu_time / self.N} seconds')
-
-    vin_time = 0.0
-    for _ in range(self.N):
-      thread = threading.Thread(target=get_vin, args=(fake_socket, fake_socket, 1))
-      vin_time += self._run_thread(thread)
-    self._assert_timing(vin_time / self.N, vin_ref_time)
-    print(f'get_vin, query time={vin_time / self.N} seconds')
+    self.total_time = 0.0
+    with (mock.patch("openpilot.selfdrive.car.fw_versions.set_obd_multiplexing", self.fake_set_obd_multiplexing),
+          mock.patch("openpilot.selfdrive.car.fw_versions.get_ecu_addrs", fake_get_ecu_addrs)):
+      for _ in range(self.N):
+        self.current_obd_multiplexing = True
+        get_present_ecus(fake_socket, fake_socket, num_pandas=2)
+    self._assert_timing(self.total_time / self.N, present_ecu_ref_time)
+    print(f'get_present_ecus, query time={self.total_time / self.N} seconds')
+
+    self.total_time = 0.0
+    with (mock.patch("openpilot.selfdrive.car.isotp_parallel_query.IsoTpParallelQuery.get_data", self.fake_get_data)):
+      for _ in range(self.N):
+        get_vin(fake_socket, fake_socket, 1)
+    self._assert_timing(self.total_time / self.N, vin_ref_time)
+    print(f'get_vin, query time={self.total_time / self.N} seconds')
 
   @pytest.mark.timeout(60)
   def test_fw_query_timing(self):
-    total_ref_time = 6.41
+    total_ref_time = 6.1
     brand_ref_times = {
       1: {
-        'body': 0.11,
+        'body': 0.1,
         'chrysler': 0.3,
         'ford': 0.2,
-        'honda': 0.52,
-        'hyundai': 0.72,
+        'honda': 0.45,
+        'hyundai': 0.65,
         'mazda': 0.2,
         'nissan': 0.4,
-        'subaru': 0.52,
+        'subaru': 0.45,
         'tesla': 0.2,
         'toyota': 1.6,
         'volkswagen': 0.2,
       },
       2: {
         'ford': 0.3,
-        'hyundai': 1.12,
+        'hyundai': 1.05,
       }
     }