diff --git a/eeschema/sim/sim_model.cpp b/eeschema/sim/sim_model.cpp
index 9332d71a17..266dbd4b71 100644
--- a/eeschema/sim/sim_model.cpp
+++ b/eeschema/sim/sim_model.cpp
@@ -883,42 +883,6 @@ void SIM_MODEL::SetParamValue( const std::string& aParamName, const std::string&
 }
 
 
-bool SIM_MODEL::HasOverrides() const
-{
-    for( const PARAM& param : m_params )
-    {
-        if( param.value != "" )
-            return true;
-    }
-
-    return false;
-}
-
-
-bool SIM_MODEL::HasNonInstanceOverrides() const
-{
-    for( const PARAM& param : m_params )
-    {
-        if( !param.info.isInstanceParam && param.value != "" )
-            return true;
-    }
-
-    return false;
-}
-
-
-bool SIM_MODEL::HasSpiceNonInstanceOverrides() const
-{
-    for( const PARAM& param : m_params )
-    {
-        if( !param.info.isSpiceInstanceParam && param.value != "" )
-            return true;
-    }
-
-    return false;
-}
-
-
 std::unique_ptr<SIM_MODEL> SIM_MODEL::Create( TYPE aType )
 {
     switch( aType )
diff --git a/eeschema/sim/sim_model.h b/eeschema/sim/sim_model.h
index e1e00b40e2..9d5e75ed0e 100644
--- a/eeschema/sim/sim_model.h
+++ b/eeschema/sim/sim_model.h
@@ -480,10 +480,6 @@ public:
     void SetParamValue( const std::string& aParamName, const std::string& aValue,
                         SIM_VALUE::NOTATION aNotation = SIM_VALUE::NOTATION::SI );
 
-    bool HasOverrides() const;
-    bool HasNonInstanceOverrides() const;
-    bool HasSpiceNonInstanceOverrides() const;
-
     // Can modifying a model parameter also modify other parameters?
     virtual bool HasAutofill() const { return false; }
     virtual bool HasPrimaryValue() const { return false; }
diff --git a/eeschema/sim/sim_model_ngspice.cpp b/eeschema/sim/sim_model_ngspice.cpp
index 6dfdbf307e..2d1a31adde 100644
--- a/eeschema/sim/sim_model_ngspice.cpp
+++ b/eeschema/sim/sim_model_ngspice.cpp
@@ -215,6 +215,43 @@ bool SIM_MODEL_NGSPICE::canSilentlyIgnoreParam( const std::string& aParamName )
 }
 
 
+bool SIM_MODEL_NGSPICE::requiresSpiceModelLine() const
+{
+    for( int ii = 0; ii < GetParamCount(); ++ii )
+    {
+        const PARAM& param = m_params[ii];
+
+        // Instance parameters are written in item lines
+        if( param.info.isSpiceInstanceParam )
+            continue;
+
+        // Empty parameters are interpreted as default-value
+        if ( param.value == "" )
+            continue;
+
+        // Any non-empty parameter must be written if there's no base model
+        if( !m_baseModel )
+            return true;
+
+        const SIM_MODEL_NGSPICE* baseModel = dynamic_cast<const SIM_MODEL_NGSPICE*>( m_baseModel );
+        std::string              baseValue = baseModel->m_params[ii].value;
+
+        if( param.value == baseValue )
+            continue;
+
+        // One more check for equivalence, mostly for early 7.0 files which wrote all parameters
+        // to the Sim.Params field in normalized format
+        if( param.value == SIM_VALUE::Normalize( SIM_VALUE::ToDouble( baseValue ) ) )
+            continue;
+
+        // Overrides must be written
+        return true;
+    }
+
+    return false;
+}
+
+
 std::vector<std::string> SIM_MODEL_NGSPICE::GetPinNames() const
 {
     return ModelInfo( getModelType() ).pinNames;
@@ -289,41 +326,3 @@ SIM_MODEL_NGSPICE::MODEL_TYPE SIM_MODEL_NGSPICE::getModelType() const
         return MODEL_TYPE::NONE;
     }
 }
-
-
-bool SIM_MODEL_NGSPICE::getIsOtherVariant()
-{
-    switch( GetType() )
-    {
-    case TYPE::PNP_GUMMELPOON:
-    case TYPE::PNP_VBIC:
-    case TYPE::PNP_HICUM2:
-    case TYPE::PJFET_SHICHMANHODGES:
-    case TYPE::PJFET_PARKERSKELLERN:
-    case TYPE::PMES_STATZ:
-    case TYPE::PMES_YTTERDAL:
-    case TYPE::PMES_HFET1:
-    case TYPE::PMES_HFET2:
-    case TYPE::PMOS_VDMOS:
-    case TYPE::PMOS_MOS1:
-    case TYPE::PMOS_MOS2:
-    case TYPE::PMOS_MOS3:
-    case TYPE::PMOS_BSIM1:
-    case TYPE::PMOS_BSIM2:
-    case TYPE::PMOS_MOS6:
-    case TYPE::PMOS_BSIM3:
-    case TYPE::PMOS_MOS9:
-    case TYPE::PMOS_B4SOI:
-    case TYPE::PMOS_BSIM4:
-    case TYPE::PMOS_B3SOIFD:
-    case TYPE::PMOS_B3SOIDD:
-    case TYPE::PMOS_B3SOIPD:
-    case TYPE::PMOS_HISIM2:
-    case TYPE::PMOS_HISIMHV1:
-    case TYPE::PMOS_HISIMHV2:
-        return true;
-
-    default:
-        return false;
-    }
-}
diff --git a/eeschema/sim/sim_model_ngspice.h b/eeschema/sim/sim_model_ngspice.h
index 5348334655..e41fa1143d 100644
--- a/eeschema/sim/sim_model_ngspice.h
+++ b/eeschema/sim/sim_model_ngspice.h
@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2022 Mikolaj Wielgus
- * Copyright (C) 2022 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2022-2023 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -109,15 +109,11 @@ protected:
     int doFindParam( const std::string& aParamName ) const override;
 
 private:
-    bool requiresSpiceModelLine() const override
-    {
-        return getModelType() != MODEL_TYPE::NONE;
-    }
+    bool requiresSpiceModelLine() const override;
 
     bool canSilentlyIgnoreParam( const std::string& aParamName );
 
     MODEL_TYPE getModelType() const;
-    bool getIsOtherVariant();
 };
 
 #endif /* SIM_MODEL_NGSPICE_H */
diff --git a/eeschema/sim/spice_generator.cpp b/eeschema/sim/spice_generator.cpp
index 96361be4bf..2e952f10a1 100644
--- a/eeschema/sim/spice_generator.cpp
+++ b/eeschema/sim/spice_generator.cpp
@@ -44,7 +44,7 @@ std::string SPICE_GENERATOR::ModelName( const SPICE_ITEM& aItem ) const
 
 std::string SPICE_GENERATOR::ModelLine( const SPICE_ITEM& aItem ) const
 {
-    if( !m_model.HasSpiceNonInstanceOverrides() && !m_model.requiresSpiceModelLine() )
+    if( !m_model.requiresSpiceModelLine() )
         return "";
 
     std::string result;