diff --git a/tests/test_internal/test_regsurf.py b/tests/test_internal/test_regsurf.py
index 8781700d1..140f54814 100644
--- a/tests/test_internal/test_regsurf.py
+++ b/tests/test_internal/test_regsurf.py
@@ -14,27 +14,11 @@
 
 import xtgeo
 import xtgeo._internal as _internal  # type: ignore
-from xtgeo.common.log import functimer, null_logger
+from xtgeo.common.log import null_logger
 
 logger = null_logger(__name__)
 
 
-@pytest.fixture(scope="module", name="get_drogondata")
-def fixture_get_drogondata(testdata_path):
-    grid = xtgeo.grid_from_file(f"{testdata_path}/3dgrids/drogon/2/geogrid.roff")
-    poro = xtgeo.gridproperty_from_file(
-        f"{testdata_path}/3dgrids/drogon/2/geogrid--phit.roff"
-    )
-    facies = xtgeo.gridproperty_from_file(
-        f"{testdata_path}/3dgrids/drogon/2/geogrid--facies.roff"
-    )
-
-    surf = xtgeo.surface_from_file(
-        f"{testdata_path}/surfaces/drogon/1/01_topvolantis.gri"
-    )
-    return grid, poro, facies, surf
-
-
 def test_find_cell_range_simple_norotated():
     surf = xtgeo.RegularSurface(
         xori=0, yori=0, xinc=1, yinc=2, ncol=3, nrow=4, rotation=0
@@ -214,97 +198,20 @@ def test_get_xy_from_ij():
     assert point.y == pytest.approx(4.4641016151)
 
 
-@pytest.mark.parametrize(
-    "x, y, rotation, expected",
-    [
-        (2.746, 1.262, 0, 17.73800),
-        (2.096, 4.897, 0, 17.473),
-        (2.746, 2.262, 0, np.nan),
-        (1.9999999999, 1.999999999, 0, 14.0),
-        (1999, 1999, 0, np.nan),  # far outside
-        (2.746, 1.262, 10, 18.3065),
-        (2.096, 4.897, 10, 21.9457),
-        (2.746, 1.262, 20, 18.319),
-        (2.096, 4.897, 20, 25.751),
-        (-0.470, -3.354, 210, np.nan),
-        (-0.013, -5.148, 210, 19.963),  # rms gets 19.959
-        (-1.433, -5.359, 210, 27.448),  # rms gets 27.452
-    ],
-)
-def test_get_z_from_xy_simple(x, y, rotation, expected):
-    """Test values are manually verified by inspection in RMS"""
-    values = np.array(range(30)).reshape(5, 6).astype(float)
-
-    values[2, 3] = np.nan
-    values[4, 5] = np.nan
-
-    surf = xtgeo.RegularSurface(
-        xori=0, yori=0, xinc=1, yinc=1, ncol=5, nrow=6, rotation=rotation, values=values
+@pytest.fixture(scope="module", name="get_drogondata")
+def fixture_get_drogondata(testdata_path):
+    grid = xtgeo.grid_from_file(f"{testdata_path}/3dgrids/drogon/2/geogrid.roff")
+    poro = xtgeo.gridproperty_from_file(
+        f"{testdata_path}/3dgrids/drogon/2/geogrid--phit.roff"
     )
-
-    z_value = _internal.regsurf.get_z_from_xy(
-        x,
-        y,
-        surf.xori,
-        surf.yori,
-        surf.xinc,
-        surf.yinc,
-        surf.ncol,
-        surf.nrow,
-        surf.rotation,
-        surf.values,
+    facies = xtgeo.gridproperty_from_file(
+        f"{testdata_path}/3dgrids/drogon/2/geogrid--facies.roff"
     )
 
-    if np.isnan(expected):
-        assert np.isnan(z_value)
-    else:
-        assert z_value == pytest.approx(expected, abs=0.001)
-
-
-@functimer
-def test_get_z_from_xy(get_drogondata):
-    _, _, _, srf = get_drogondata
-
-    surf = srf.copy()
-
-    z_value = _internal.regsurf.get_z_from_xy(
-        460103.00,
-        5934855.00,
-        surf.xori,
-        surf.yori,
-        surf.xinc,
-        surf.yinc,
-        surf.ncol,
-        surf.nrow,
-        surf.rotation,
-        surf.values,
+    surf = xtgeo.surface_from_file(
+        f"{testdata_path}/surfaces/drogon/1/01_topvolantis.gri"
     )
-
-    assert z_value == pytest.approx(1594.303, abs=0.001)
-
-    # make ntimes random points and check the time (cf. @functimer with debug logging)
-    ntimes = 100000
-    xmin = 458000
-    xmax = 468000
-    ymin = 5927000
-    ymax = 5938000
-    logger.debug("Start random points loop... %s", ntimes)
-    for _ in range(ntimes):
-        x = np.random.uniform(xmin, xmax)
-        y = np.random.uniform(ymin, ymax)
-        _internal.regsurf.get_z_from_xy(
-            x,
-            y,
-            surf.xori,
-            surf.yori,
-            surf.xinc,
-            surf.yinc,
-            surf.ncol,
-            surf.nrow,
-            surf.rotation,
-            surf.values,
-        )
-    logger.debug("End random points loop")
+    return grid, poro, facies, surf
 
 
 def test_sample_grid3d_layer(get_drogondata):