diff --git a/fastsim-core/fastsim-proc-macros/src/serde_api/serde_utils.rs b/fastsim-core/fastsim-proc-macros/src/serde_api/serde_utils.rs
index c6ed66f4..ffc6572c 100644
--- a/fastsim-core/fastsim-proc-macros/src/serde_api/serde_utils.rs
+++ b/fastsim-core/fastsim-proc-macros/src/serde_api/serde_utils.rs
@@ -362,8 +362,7 @@ pub(crate) fn serde_attrs_for_si_fields(field: &mut syn::Field) -> Option<()> {
 
         // Determine the canonical (serialization) unit and serialize_with path.
         //
-        // With no field-level override: use the first entry from quantity_config,
-        // except Ratio which preserves a legacy bare-name canonical serialization key.
+        // With no field-level override: use the first entry from quantity_config.
         // With `#[si_unit(name)]`: use the specified unit, constructing a serialize_with
         // path of the form `fastsim_core::utils::serde_helpers::{quantity_snake}_as_{unit}`
         // unless the unit is the SI base unit (first entry, no global serialize_with),
@@ -408,10 +407,6 @@ pub(crate) fn serde_attrs_for_si_fields(field: &mut syn::Field) -> Option<()> {
                         (override_name.clone(), serialize_with)
                     }
                 }
-            } else if quantity == "Ratio" {
-                // Legacy escape hatch: keep bare field names canonical for Ratio fields
-                // unless an explicit override is provided.
-                (String::new(), None)
             } else {
                 let canonical = unit_impls
                     .first()
@@ -511,8 +506,12 @@ fn quantity_config(quantity: &str) -> Option<(Vec<(TokenStream2, String)>, Optio
             None,
         )),
         "Energy" => Some((
-            extract_units!(uom::si::energy::joule, uom::si::energy::kilowatt_hour),
-            None,
+            extract_units!(
+                uom::si::energy::kilojoule,
+                uom::si::energy::kilowatt_hour,
+                uom::si::energy::joule
+            ),
+            Some("fastsim_core::utils::serde_helpers::energy_as_kilojoules"),
         )),
         // "EnergyDensity" => Some((
         //     vec![(
@@ -558,33 +557,23 @@ fn quantity_config(quantity: &str) -> Option<(Vec<(TokenStream2, String)>, Optio
             extract_units!(uom::si::moment_of_inertia::kilogram_square_meter),
             None,
         )),
-        // First entry = canonical serialization unit.
-        // To serialize Power in kilowatts, move kilowatt to first and set serialize_with:
-        // "Power" => Some((
-        //     extract_units!(
-        //         uom::si::power::kilowatt,
-        //         uom::si::power::watt,
-        //         uom::si::power::horsepower
-        //     ),
-        //     Some("fastsim_core::utils::serde_helpers::power_as_kilowatts"),
-        // )),
         "Power" => Some((
             extract_units!(
-                uom::si::power::watt,
                 uom::si::power::kilowatt,
+                uom::si::power::watt,
                 uom::si::power::horsepower
             ),
-            None,
+            Some("fastsim_core::utils::serde_helpers::power_as_kilowatts"),
         )),
         "PowerRate" => Some((extract_units!(uom::si::power_rate::watt_per_second), None)),
         "Pressure" => Some((
             extract_units!(
-                uom::si::pressure::pascal,
                 uom::si::pressure::kilopascal,
+                uom::si::pressure::pascal,
                 uom::si::pressure::bar,
                 uom::si::pressure::pound_force_per_square_inch
             ),
-            None,
+            Some("fastsim_core::utils::serde_helpers::pressure_as_kilopascals"),
         )),
         "Ratio" => Some((
             extract_units!(uom::si::ratio::ratio, uom::si::ratio::percent),
@@ -595,44 +584,47 @@ fn quantity_config(quantity: &str) -> Option<(Vec<(TokenStream2, String)>, Optio
             // as custom uom units (not present upstream). extract_custom_units! takes
             // ("path", "name") string literals because the proc-macro binary cannot link
             // against downstream crates to call Unit::plural().
-            let mut units = extract_units!(
-                uom::si::available_energy::joule_per_kilogram,
-                uom::si::available_energy::kilojoule_per_kilogram
-            );
-            units.extend(extract_custom_units!(
-                (
-                    "fastsim_core::si::watt_hour_per_kilogram",
-                    "watt_hours_per_kilogram"
-                ),
+            let mut units = extract_custom_units!(
                 (
                     "fastsim_core::si::kilowatt_hour_per_kilogram",
                     "kilowatt_hours_per_kilogram"
+                ),
+                (
+                    "fastsim_core::si::watt_hour_per_kilogram",
+                    "watt_hours_per_kilogram"
                 )
+            );
+            units.extend(extract_units!(
+                uom::si::available_energy::kilojoule_per_kilogram,
+                uom::si::available_energy::joule_per_kilogram
             ));
-            Some((units, None))
+            Some((
+                units,
+                Some("fastsim_core::utils::serde_helpers::specific_energy_as_kilowatt_hours_per_kilogram"),
+            ))
         }
         "SpecificPower" => Some((
             extract_units!(
-                uom::si::specific_power::watt_per_kilogram,
-                uom::si::specific_power::kilowatt_per_kilogram
+                uom::si::specific_power::kilowatt_per_kilogram,
+                uom::si::specific_power::watt_per_kilogram
             ),
-            None,
+            Some("fastsim_core::utils::serde_helpers::specific_power_as_kilowatts_per_kilogram"),
         )),
         "Temperature" => Some((
             extract_units!(
-                uom::si::thermodynamic_temperature::kelvin,
                 uom::si::thermodynamic_temperature::degree_celsius,
+                uom::si::thermodynamic_temperature::kelvin,
                 uom::si::thermodynamic_temperature::degree_fahrenheit
             ),
-            None,
+            Some("fastsim_core::utils::serde_helpers::temperature_as_degrees_celsius"),
         )),
         "TemperatureInterval" => Some((
             extract_units!(
-                uom::si::temperature_interval::kelvin,
                 uom::si::temperature_interval::degree_celsius,
+                uom::si::temperature_interval::kelvin,
                 uom::si::temperature_interval::degree_fahrenheit
             ),
-            None,
+            Some("fastsim_core::utils::serde_helpers::temperature_interval_as_degrees_celsius"),
         )),
         "ThermalConductance" => Some((
             extract_units!(uom::si::thermal_conductance::watt_per_kelvin),
@@ -784,11 +776,8 @@ pub fn generate_helper_struct(
                         // Field-unit is canonical by default, with bare-field aliasing for the
                         // SI base unit. A field-level `#[si_unit(unitless)]` override switches
                         // canonical naming to bare field for the base unit.
-                        // Legacy escape hatch: unannotated Ratio fields also serialize bare.
-                        let ratio_escape_hatch = si_field.quantity == "Ratio";
-                        let use_bare_as_canonical = (si_field.unitless_canonical
-                            || ratio_escape_hatch)
-                            && idx == base_unit_idx;
+                        let use_bare_as_canonical =
+                            si_field.unitless_canonical && idx == base_unit_idx;
                         let (canonical_name, unit_alias) = if use_bare_as_canonical {
                             (bare_name.clone(), serde_key.clone())
                         } else {
diff --git a/fastsim-core/src/drive_cycle.rs b/fastsim-core/src/drive_cycle.rs
index 16191ebe..6fa96cee 100644
--- a/fastsim-core/src/drive_cycle.rs
+++ b/fastsim-core/src/drive_cycle.rs
@@ -31,6 +31,7 @@ pub struct Cycle {
     pub dist: Vec<si::Length>,
     /// road grade (expressed as a decimal, not percent)
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    #[si_unit(percent)]
     pub grade: Vec<si::Ratio>,
     // TODO: consider trapezoidal integration scheme
     // TODO: @mokeefe, please check out how elevation is handled
@@ -1604,6 +1605,7 @@ pub struct CycleElement {
     // `dist` is not included here because it is derived in `Init::init`
     /// road grade
     #[serde(alias = "cycGrade")]
+    #[si_unit(percent)]
     pub grade: Option<si::Ratio>,
     // `elev` is not included here because it is derived in `Init::init`
     /// road charging/discharing capacity
diff --git a/fastsim-core/src/utils/serde_helpers.rs b/fastsim-core/src/utils/serde_helpers.rs
index dbf92932..c3ee6e04 100644
--- a/fastsim-core/src/utils/serde_helpers.rs
+++ b/fastsim-core/src/utils/serde_helpers.rs
@@ -41,4 +41,36 @@
 #[allow(unused_imports)]
 use crate::si;
 
+crate::impl_si_serialize_as!(energy_as_kilojoules, si::Energy, uom::si::energy::kilojoule);
+crate::impl_si_serialize_as!(
+    energy_as_kilowatt_hours,
+    si::Energy,
+    crate::si::kilowatt_hour
+);
 crate::impl_si_serialize_as!(power_as_kilowatts, si::Power, uom::si::power::kilowatt);
+crate::impl_si_serialize_as!(
+    pressure_as_kilopascals,
+    si::Pressure,
+    uom::si::pressure::kilopascal
+);
+crate::impl_si_serialize_as!(ratio_as_percent, si::Ratio, uom::si::ratio::percent);
+crate::impl_si_serialize_as!(
+    specific_energy_as_kilowatt_hours_per_kilogram,
+    si::SpecificEnergy,
+    crate::si::kilowatt_hour_per_kilogram
+);
+crate::impl_si_serialize_as!(
+    specific_power_as_kilowatts_per_kilogram,
+    si::SpecificPower,
+    crate::si::kilowatt_per_kilogram
+);
+crate::impl_si_serialize_as!(
+    temperature_as_degrees_celsius,
+    si::Temperature,
+    uom::si::thermodynamic_temperature::degree_celsius
+);
+crate::impl_si_serialize_as!(
+    temperature_interval_as_degrees_celsius,
+    si::TemperatureInterval,
+    uom::si::temperature_interval::degree_celsius
+);
diff --git a/fastsim-core/src/vehicle/chassis.rs b/fastsim-core/src/vehicle/chassis.rs
index 65e60c0b..9d0494f2 100755
--- a/fastsim-core/src/vehicle/chassis.rs
+++ b/fastsim-core/src/vehicle/chassis.rs
@@ -27,10 +27,12 @@ impl Init for DriveTypes {}
 /// Struct for simulating vehicle
 pub struct Chassis {
     /// Aerodynamic drag coefficient
+    #[si_unit(unitless)]
     pub drag_coef: si::Ratio,
     /// Projected frontal area for drag calculations
     pub frontal_area: si::Area,
     /// Wheel rolling resistance coefficient for the vehicle (i.e. all wheels included)
+    #[si_unit(unitless)]
     pub wheel_rr_coef: si::Ratio,
     /// Wheel inertia per wheel
     pub wheel_inertia: si::MomentOfInertia,
@@ -45,6 +47,7 @@ pub struct Chassis {
     /// Vehicle center of mass height
     pub cg_height: si::Length,
     /// Wheel coefficient of friction
+    #[si_unit(unitless)]
     pub wheel_fric_coef: si::Ratio,
 
     /// Drive wheel configuration
diff --git a/fastsim-core/src/vehicle/conv.rs b/fastsim-core/src/vehicle/conv.rs
index 26ffcf1c..882a79ff 100644
--- a/fastsim-core/src/vehicle/conv.rs
+++ b/fastsim-core/src/vehicle/conv.rs
@@ -178,6 +178,7 @@ pub struct ConventionalVehicle {
     /// powertrain mass
     pub(crate) mass: Option<si::Mass>,
     /// Alternator efficiency used to calculate aux mechanical power demand on engine
+    #[si_unit(percent)]
     pub alt_eff: si::Ratio,
 }
 
diff --git a/fastsim-core/src/vehicle/hev.rs b/fastsim-core/src/vehicle/hev.rs
index 8c9ee7cf..c89a754e 100644
--- a/fastsim-core/src/vehicle/hev.rs
+++ b/fastsim-core/src/vehicle/hev.rs
@@ -575,6 +575,7 @@ pub struct RGWDBState {
     /// SOC is below min buffer so FC is charging RES
     pub charging_for_low_soc: TrackedState<bool>,
     /// buffer at which FC is forced on
+    #[si_unit(percent)]
     pub soc_fc_on_buffer: TrackedState<si::Ratio>,
 }
 impl SerdeAPI for RGWDBState {}
@@ -865,17 +866,20 @@ pub struct RESGreedyWithDynamicBuffers {
     /// vehicle at this speed that triggers ramp down in RES discharge.
     pub speed_soc_disch_buffer: Option<si::Velocity>,
     /// Coefficient for modifying amount of accel buffer
+    #[si_unit(percent)]
     pub speed_soc_disch_buffer_coeff: Option<si::Ratio>,
     /// RES energy delta from minimum SOC corresponding to kinetic energy of
     /// vehicle at this speed that triggers FC to be forced on.
     pub speed_soc_fc_on_buffer: Option<si::Velocity>,
     /// Coefficient for modifying amount of [Self::speed_soc_fc_on_buffer]
+    #[si_unit(percent)]
     pub speed_soc_fc_on_buffer_coeff: Option<si::Ratio>,
     /// RES energy delta from maximum SOC corresponding to kinetic energy of
     /// vehicle at current speed minus kinetic energy of vehicle at this speed
     /// triggers ramp down in RES discharge
     pub speed_soc_regen_buffer: Option<si::Velocity>,
     /// Coefficient for modifying amount of regen buffer
+    #[si_unit(percent)]
     pub speed_soc_regen_buffer_coeff: Option<si::Ratio>,
     /// Minimum time engine must remain on if it was on during the previous
     /// simulation time step.
@@ -1268,6 +1272,7 @@ pub struct HEVStartStopControl {
     pub fc_min_time_on: Option<si::Time>,
     /// The range of usable SOC of the storage system below which the
     /// [FuelConverter] is forced on.
+    #[si_unit(percent)]
     pub soc_fc_forced_on: Option<si::Ratio>,
     /// Force engine, if on, to run at this fraction of power at which peak
     /// efficiency occurs or the required power, whichever is greater. If SOC is
diff --git a/fastsim-core/src/vehicle/hvac/hvac_sys_for_lumped_cabin.rs b/fastsim-core/src/vehicle/hvac/hvac_sys_for_lumped_cabin.rs
index 73c4e98b..b038950e 100644
--- a/fastsim-core/src/vehicle/hvac/hvac_sys_for_lumped_cabin.rs
+++ b/fastsim-core/src/vehicle/hvac/hvac_sys_for_lumped_cabin.rs
@@ -523,6 +523,7 @@ pub struct HVACSystemForLumpedCabinState {
     /// portion of total HVAC cooling/heating (negative/positive) cumulative energy due to derivative gain
     pub energy_d: TrackedState<si::Energy>,
     /// coefficient of performance (i.e. efficiency) of vapor compression cycle
+    #[si_unit(unitless)]
     pub cop: TrackedState<Option<si::Ratio>>,
     /// Aux power demand from [Vehicle::hvac] system
     pub pwr_aux_for_hvac: TrackedState<si::Power>,
diff --git a/fastsim-core/src/vehicle/hvac/hvac_sys_for_lumped_cabin_and_res.rs b/fastsim-core/src/vehicle/hvac/hvac_sys_for_lumped_cabin_and_res.rs
index f1285c93..7dcdf440 100644
--- a/fastsim-core/src/vehicle/hvac/hvac_sys_for_lumped_cabin_and_res.rs
+++ b/fastsim-core/src/vehicle/hvac/hvac_sys_for_lumped_cabin_and_res.rs
@@ -1200,6 +1200,7 @@ pub struct HVACSystemForLumpedCabinAndRESState {
     /// to [ReversibleEnergyStorage::thrml] due to derivative gain
     pub energy_d_res: TrackedState<si::Energy>,
     /// coefficient of performance (i.e. efficiency) of vapor compression cycle
+    #[si_unit(unitless)]
     pub cop: TrackedState<Option<si::Ratio>>,
     /// Reference temperature used to calculate coefficient of performance (i.e.
     /// efficiency) of vapor compression cycle
diff --git a/fastsim-core/src/vehicle/powertrain/electric_machine.rs b/fastsim-core/src/vehicle/powertrain/electric_machine.rs
index f8a06515..c2e6e541 100755
--- a/fastsim-core/src/vehicle/powertrain/electric_machine.rs
+++ b/fastsim-core/src/vehicle/powertrain/electric_machine.rs
@@ -877,15 +877,18 @@ pub struct ElectricMachineState {
     /// time step index
     pub i: TrackedState<usize>,
     /// Component efficiency based on current power demand.
+    #[si_unit(percent)]
     pub eff: TrackedState<si::Ratio>,
     // Component limits
     /// Maximum possible positive traction power.
     pub pwr_mech_fwd_out_max: TrackedState<si::Power>,
     /// efficiency in forward direction at max possible input power from `FuelConverter` and `ReversibleEnergyStorage`
+    #[si_unit(percent)]
     pub eff_fwd_at_max_input: TrackedState<si::Ratio>,
     /// Maximum possible regeneration power going to ReversibleEnergyStorage.
     pub pwr_mech_regen_max: TrackedState<si::Power>,
     /// efficiency in backward direction at max possible input power from `FuelConverter` and `ReversibleEnergyStorage`
+    #[si_unit(percent)]
     pub eff_at_max_regen: TrackedState<si::Ratio>,
 
     // Current values
diff --git a/fastsim-core/src/vehicle/powertrain/fuel_converter.rs b/fastsim-core/src/vehicle/powertrain/fuel_converter.rs
index d40ce51a..9da012dd 100755
--- a/fastsim-core/src/vehicle/powertrain/fuel_converter.rs
+++ b/fastsim-core/src/vehicle/powertrain/fuel_converter.rs
@@ -567,6 +567,7 @@ pub struct FuelConverterState {
     /// max propulsion power fc can produce at current time
     pub pwr_prop_max: TrackedState<si::Power>,
     /// efficiency evaluated at current demand
+    #[si_unit(percent)]
     pub eff: TrackedState<si::Ratio>,
     /// instantaneous power going to drivetrain, not including aux
     pub pwr_prop: TrackedState<si::Power>,
@@ -1152,6 +1153,7 @@ pub struct FuelConverterThermalState {
     /// Cumulative heat transfer energy to ambient
     pub energy_thrml_to_amb: TrackedState<si::Energy>,
     /// Efficency coefficient, used to modify [FuelConverter] effciency based on temperature
+    #[si_unit(percent)]
     pub eff_coeff: TrackedState<si::Ratio>,
     /// Thermal power flowing from fuel converter to cabin
     pub pwr_thrml_fc_to_cab: TrackedState<si::Power>,
diff --git a/fastsim-core/src/vehicle/powertrain/fuel_storage.rs b/fastsim-core/src/vehicle/powertrain/fuel_storage.rs
index f422bf28..84db919f 100644
--- a/fastsim-core/src/vehicle/powertrain/fuel_storage.rs
+++ b/fastsim-core/src/vehicle/powertrain/fuel_storage.rs
@@ -21,6 +21,7 @@ pub struct FuelStorage {
     #[serde(default)]
     pub fuel_type: Option<FuelType>,
     /// energy capacity
+    #[si_unit(kilowatt_hours)]
     pub energy_capacity: si::Energy,
     /// Fuel and tank specific energy
     pub(crate) specific_energy: Option<si::SpecificEnergy>,
diff --git a/fastsim-core/src/vehicle/powertrain/reversible_energy_storage.rs b/fastsim-core/src/vehicle/powertrain/reversible_energy_storage.rs
index cd9c005f..2a6caaed 100644
--- a/fastsim-core/src/vehicle/powertrain/reversible_energy_storage.rs
+++ b/fastsim-core/src/vehicle/powertrain/reversible_energy_storage.rs
@@ -27,14 +27,17 @@ pub struct ReversibleEnergyStorage {
     pub pwr_out_max: si::Power,
 
     /// Total energy capacity of battery of full discharge SOC of 0.0 and 1.0
+    #[si_unit(kilowatt_hours)]
     pub energy_capacity: si::Energy,
 
     /// interpolator for calculating [Self] efficiency
     pub eff_interp: RESEfficiency,
 
     /// Hard limit on minimum SOC, e.g. 0.05
+    #[si_unit(percent)]
     pub min_soc: si::Ratio,
     /// Hard limit on maximum SOC, e.g. 0.95
+    #[si_unit(percent)]
     pub max_soc: si::Ratio,
     /// struct for tracking current state
     #[serde(default)]
@@ -889,17 +892,22 @@ pub struct ReversibleEnergyStorageState {
     pub i: TrackedState<usize>,
 
     /// state of charge (SOC)
+    #[si_unit(percent)]
     pub soc: TrackedState<si::Ratio>,
     /// SOC at which [ReversibleEnergyStorage] regen power begins linearly
     /// derating as it approaches maximum SOC
+    #[si_unit(percent)]
     pub soc_regen_buffer: TrackedState<si::Ratio>,
     /// SOC at which [ReversibleEnergyStorage] discharge power begins linearly
     /// derating as it approaches minimum SOC
+    #[si_unit(percent)]
     pub soc_disch_buffer: TrackedState<si::Ratio>,
     /// Chemical <-> Electrical conversion efficiency based on current power demand
+    #[si_unit(percent)]
     pub eff: TrackedState<si::Ratio>,
     /// State of Health (SOH)
-    pub soh: TrackedState<f64>,
+    #[si_unit(percent)]
+    pub soh: TrackedState<si::Ratio>,
 
     // TODO: add `pwr_out_neg_electrical` and `pwr_out_pos_electrical` and corresponding energies
     // powers to separately pin negative- and positive-power operation
diff --git a/fastsim-core/src/vehicle/powertrain/transmission.rs b/fastsim-core/src/vehicle/powertrain/transmission.rs
index 930eca77..3224b420 100644
--- a/fastsim-core/src/vehicle/powertrain/transmission.rs
+++ b/fastsim-core/src/vehicle/powertrain/transmission.rs
@@ -225,6 +225,7 @@ pub struct TransmissionState {
     pub pwr_out_regen_max: TrackedState<si::Power>,
 
     /// efficiency at current time step
+    #[si_unit(percent)]
     pub eff: TrackedState<si::Ratio>,
 
     /// Power at output side of transmission.  Positive indicates forward power
diff --git a/fastsim-core/src/vehicle/vehicle_model.rs b/fastsim-core/src/vehicle/vehicle_model.rs
index e0169959..9fd50b86 100644
--- a/fastsim-core/src/vehicle/vehicle_model.rs
+++ b/fastsim-core/src/vehicle/vehicle_model.rs
@@ -1361,6 +1361,7 @@ pub struct VehicleState {
     /// cumulative distance traveled, integral of [Self::speed_ach]
     pub dist: TrackedState<si::Length>,
     /// current grade
+    #[si_unit(percent)]
     pub grade_curr: TrackedState<si::Ratio>,
     /// current grade
     // will be overridden during simulation anyway
diff --git a/fastsim-core/tests/test_serde_api_integration.rs b/fastsim-core/tests/test_serde_api_integration.rs
index 51744455..ef54af57 100644
--- a/fastsim-core/tests/test_serde_api_integration.rs
+++ b/fastsim-core/tests/test_serde_api_integration.rs
@@ -294,16 +294,16 @@ fn test_serialize_uses_prescribed_units() {
         serde_json::from_str(&serialized).expect("Failed to parse serialized JSON");
 
     assert!(value.get("mass_kilograms").is_some());
-    assert!(value.get("power_watts").is_some());
+    assert!(value.get("power_kilowatts").is_some());
     assert!(value.get("speed_meters_per_second").is_some());
     assert!(value.get("duration_seconds").is_some());
     assert!(value.get("area_square_meters").is_some());
-    assert!(value.get("temperature_kelvin").is_some());
-    assert!(value.get("energy_joules").is_some());
+    assert!(value.get("temperature_degrees_celsius").is_some());
+    assert!(value.get("energy_kilojoules").is_some());
     assert!(value.get("efficiency").is_some()); // Ratio: bare name
-    assert!(value.get("tracked_power_watts").is_some());
+    assert!(value.get("tracked_power_kilowatts").is_some());
     assert!(value.get("tracked_efficiency").is_some()); // Ratio: bare name
-    assert!(value.get("renamed_power_watts").is_some());
+    assert!(value.get("renamed_power_kilowatts").is_some());
 }
 
 #[test]
@@ -330,14 +330,15 @@ fn test_round_trip_conversion_preserves_values() {
     let value: serde_json::Value =
         serde_json::from_str(&serialized).expect("Failed to parse serialized JSON");
 
-    // Values are preserved through round-trip (in primary units)
+    // Values are preserved through round-trip (in canonical serialized units)
     assert_eq!(value["mass_kilograms"], 2000.0);
-    assert_eq!(value["power_watts"], 150.0);
+    assert_eq!(value["power_kilowatts"], 0.15);
     assert_eq!(value["speed_meters_per_second"], 30.0);
     assert_eq!(value["duration_seconds"], 3600.0);
     assert_eq!(value["area_square_meters"], 5.0);
-    assert_eq!(value["temperature_kelvin"], 300.0);
-    assert_eq!(value["energy_joules"], 1000.0);
+    let temp_c = value["temperature_degrees_celsius"].as_f64().unwrap();
+    assert!((temp_c - 26.85).abs() < 1e-9);
+    assert_eq!(value["energy_kilojoules"], 1.0);
     assert_eq!(value["efficiency"], 0.85); // Ratio: bare name
 }
 
@@ -797,8 +798,8 @@ const SE_BASE: &str = r#"{
 }"#;
 
 #[test]
-fn test_specific_energy_serializes_as_joules_per_kilogram() {
-    // Primary serialization key for SpecificEnergy is joules_per_kilogram.
+fn test_specific_energy_serializes_as_kilowatt_hours_per_kilogram() {
+    // Primary serialization key for SpecificEnergy is kilowatt_hours_per_kilogram.
     let json = SE_BASE.replace(
         "}",
         r#", "specific_energy_watt_hours_per_kilogram": 100.0}"#,
@@ -807,14 +808,14 @@ fn test_specific_energy_serializes_as_joules_per_kilogram() {
     let serialized = serde_json::to_string(&device).unwrap();
     let value: serde_json::Value = serde_json::from_str(&serialized).unwrap();
     assert!(
-        value.get("specific_energy_joules_per_kilogram").is_some(),
-        "expected specific_energy_joules_per_kilogram in serialized output; got: {serialized}"
+        value.get("specific_energy_kilowatt_hours_per_kilogram").is_some(),
+        "expected specific_energy_kilowatt_hours_per_kilogram in serialized output; got: {serialized}"
     );
-    // 100 Wh/kg = 360 000 J/kg
-    let stored = value["specific_energy_joules_per_kilogram"]
+    // 100 Wh/kg = 0.1 kWh/kg
+    let stored = value["specific_energy_kilowatt_hours_per_kilogram"]
         .as_f64()
         .unwrap();
-    assert!((stored - 360_000.0).abs() < 1.0);
+    assert!((stored - 0.1).abs() < 1e-12);
 }
 
 #[test]
@@ -908,10 +909,10 @@ fn test_si_unit_unitless_override_changes_ratio_canonical_name() {
     assert!(value.get("alt_eff_ratio").is_none());
     assert!(value.get("cop_ratio").is_none());
 
-    // Ratio escape hatch: unannotated ratio fields also serialize bare.
+    // With Ratio escape hatch disabled, unannotated ratio fields serialize with suffix.
     assert!(
-        value.get("grade").is_some(),
-        "expected bare grade in {json}"
+        value.get("grade_ratio").is_some(),
+        "expected grade_ratio in {json}"
     );
-    assert!(value.get("grade_ratio").is_none());
+    assert!(value.get("grade").is_none());
 }
diff --git a/pyproject.toml b/pyproject.toml
index 88353a3b..a6328a69 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -63,15 +63,6 @@ dev = [
     "deepdiff>=8.4.2",
 ]
 
-[tool.setuptools]
-zip-safe = false
-
-[tool.setuptools.packages.find]
-include = [
-    "fastsim*",
-] # package names should match these glob patterns (["*"] by default)
-namespaces = false # to disable scanning PEP 420 namespaces (true by default)
-
 [tool.maturin]
 profile = "release"
 python-source = "python"