diff --git a/VectoCore/VectoCore/Models/Declaration/DeclarationData.cs b/VectoCore/VectoCore/Models/Declaration/DeclarationData.cs
index e15e1c13dc1758a94a8d6ce4711996bbd8708ce7..49d29662c04f3970fbc6975d9bd1ffa04e82fcaf 100644
--- a/VectoCore/VectoCore/Models/Declaration/DeclarationData.cs
+++ b/VectoCore/VectoCore/Models/Declaration/DeclarationData.cs
@@ -97,7 +97,7 @@ namespace TUGraz.VectoCore.Models.Declaration
 			try {
 				var rimsEntry = Rims.Lookup(rims);
 
-				var correction = wheelsEntry.SizeClass != "a" ? rimsEntry.F_b : rimsEntry.F_a;
+				var correction = rimsEntry.F_a;
 
 				return wheelsEntry.DynamicTyreRadius * correction / (2 * Math.PI);
 			} catch (KeyNotFoundException) {
diff --git a/VectoCore/VectoCore/Models/Declaration/Wheels.cs b/VectoCore/VectoCore/Models/Declaration/Wheels.cs
index dbc2aa5606bc5183a437c58423cb7cb62955cf00..1d7f842265200c74fcddcdd46c9e15e7bfa50107 100644
--- a/VectoCore/VectoCore/Models/Declaration/Wheels.cs
+++ b/VectoCore/VectoCore/Models/Declaration/Wheels.cs
@@ -52,12 +52,12 @@ namespace TUGraz.VectoCore.Models.Declaration
 
 		protected sealed override void ParseData(DataTable table)
 		{
-			Data = (from DataRow row in table.Rows
-				select new WheelsEntry {
+			Data = table.Rows.Cast<DataRow>()
+				.Select(row => new WheelsEntry {
 					WheelType = row.Field<string>(0).RemoveWhitespace(),
-					Inertia = row.ParseDouble(1).SI<KilogramSquareMeter>(),
-					DynamicTyreRadius = row.ParseDouble(2).SI().Milli.Meter.Cast<Meter>(),
-					SizeClass = row.Field<string>(3)
+					Inertia = row.ParseDouble("inertia").SI<KilogramSquareMeter>(),
+					DynamicTyreRadius = row.ParseDouble("d").SI().Milli.Meter.Cast<Meter>(),
+					CircumferenceFactor = row.ParseDouble("f")
 				}).ToDictionary(e => e.WheelType);
 		}
 
@@ -66,7 +66,7 @@ namespace TUGraz.VectoCore.Models.Declaration
 			public string WheelType;
 			public KilogramSquareMeter Inertia;
 			public Meter DynamicTyreRadius;
-			public string SizeClass;
+			public double CircumferenceFactor;
 		}
 	}
 }
\ No newline at end of file
diff --git a/VectoCore/VectoCore/Resources/Declaration/Wheels.csv b/VectoCore/VectoCore/Resources/Declaration/Wheels.csv
index 782e9ba6938fbc3f94f01f1b48bdd568536ed417..723845166b9f566c406e9a25bdcd5cf0c00c1f22 100644
--- a/VectoCore/VectoCore/Resources/Declaration/Wheels.csv
+++ b/VectoCore/VectoCore/Resources/Declaration/Wheels.csv
@@ -1,41 +1,58 @@
-Wheel,Inertia,d,Size-Class (0/1)
-9 R22.5,8.9,970,b
-9.00 R20,10.5,1018,b
-9.5 R17.5,4.9,842,b
-10 R17.5,5,858,b
-10 R22.5,11,1020,b
-10.00 R20,13.1,1025,b
-11 R22.5,14.4,1050,b
-11.00 R20,14.6,1082,b
-12 R22.5,16.8,1084,b
-12.00 R20,19.5,1122,b
-12.00 R24,27.7,1226,b
-12.5 R20,12.7,1120,b
-13 R22.5,20,1124,b
-14.00 R20,30.8,1238,b
-14.5 R20,14.8,1092,b
-16.00 R20,47.5,1343,b
-215/75 R17.5,3.9,767,b
-225/70 R17.5,4,759.5,b
-225/75 R17.5,4,782,b
-235/75 R17.5,4.5,797,b
-245/70 R17.5,5.2,787.5,b
-245/70 R19.5,6,838.3,b
-255/70 R22.5,9.5,928.5,b
-265/70 R19.5,6.5,866.3,b
-275/70 R22.5,11.9,956.5,b
-275/80 R22.5,12.8,1011.5,b
-285/70 R19.5,7.9,894.3,b
-295/55 R22.5,10.2,896,a
-295/60 R22.5,10.8,925.5,a
-295/80 R22.5,15.5,1043.5,b
-305/70 R19.5,9.2,922.3,b
-305/70 R22.5,13.9,998.5,b
-315/45 R22.5,9.9,855,a
-315/60 R22.5,12.8,949.5,a
-315/70 R22.5,14.9,1012.5,b
-315/80 R22.5,17.6,1075.5,b
-365/80 R20,17.2,1092,b
-365/85 R20,22.5,1128.5,b
-385/55 R22.5,15.9,995,a
-385/65 R22.5,19.2,1072,a
+Wheel,cross-sectional width [mm],tire aspect ratio [%],rim diameter [inch],d [mm],Inertia,F [-]
+9.5 R17.5,241.3,0.95,17.5,842,4.9,3.05
+9.00 R20,228.6,0.95,20,1018,10.5,3.05
+9 R22.5,228.6,0.95,22.5,970,8.9,3.05
+10 R17.5,254,0.95,17.5,858,5,3.05
+10 R22.5,254,0.95,22.5,1020,11,3.05
+10.00 R20,254,0.95,20,1025,13.1,3.05
+11 R22.5,279.4,0.95,22.5,1050,14.4,3.05
+11.00 R20,279.4,0.95,20,1082,14.6,3.05
+11.00 R22,279.4,0.95,22,1089.66,16,3.05
+12 R22.5,304.8,0.95,22.5,1084,16.85,3.05
+12.00 R20,304.8,0.95,20,1122,19.5,3.05
+12.00 R24,304.8,0.95,24,1226,27.7,3.05
+12.5 R20,317.5,0.95,20,1120,12.7,3.05
+13 R22.5,330.2,0.95,22.5,1124,20,3.05
+14.00 R20,355.6,0.95,20,1238,30.8,3.05
+14.5 R20,368.3,0.95,20,1092,14.8,3.05
+16.00 R20,406.4,0.95,20,1343,47.5,3.05
+205/75 R17.5,205,0.75,17.5,752,3.5,3.05
+215/75 R17.5,215,0.75,17.5,767,3.9,3.05
+225/70 R17.5,225,0.7,17.5,759.5,4,3.05
+225/75 R17.5,225,0.75,17.5,782,4,3.05
+235/75 R17.5,235,0.75,17.5,797,4.5,3.05
+245/70 R17.5,245,0.7,17.5,787.5,5.2,3.05
+245/70 R19.5,245,0.7,19.5,838.3,6,3.05
+255/70 R22.5,255,0.7,22.5,928.5,9.5,3.05
+265/70 R17.5,265,0.7,17.5,817,5.6,3.05
+265/70 R19.5,265,0.7,19.5,866.3,6.5,3.05
+275/70 R22.5,275,0.7,22.5,956.5,11.9,3.05
+275/80 R22.5,275,0.8,22.5,1011.5,12.8,3.05
+285/60 R22.5,285,0.6,22.5,913.5,10.6,3.03
+285/70 R19.5,285,0.7,19.5,894.3,7.9,3.05
+295/55 R22.5,295,0.55,22.5,896,10.2,3.03
+295/60 R22.5,295,0.6,22.5,925.5,10.8,3.03
+295/80 R22.5,295,0.8,22.5,1043.5,15.5,3.05
+305/60 R22.5,305,0.6,22.5,922.3,11.4,3.03
+305/70 R19.5,305,0.7,19.5,998.5,9.2,3.05
+305/70 R22.5,305,0.7,22.5,998.5,13.9,3.05
+305/75 R24.5,305,0.75,24.5,1079.8,21.2,3.05
+315/45 R22.5,315,0.45,22.5,855,9.9,3.03
+315/60 R22.5,315,0.6,22.5,949.5,12.8,3.03
+315/70 R22.5,315,0.7,22.5,1012.5,14.9,3.05
+315/80 R22.5,315,0.8,22.5,1075.5,17.6,3.05
+325/95 R24,325,0.95,24,1227.1,27.6,3.05
+335/80 R20,335,0.8,20,1044,13.5,3.05
+355/50 R22.5,355,0.5,22.5,926.5,12.2,3.03
+365/70 R22.5,365,0.7,22.5,1082.5,18.6,3.05
+365/80 R20,365,0.8,20,1092,17.2,3.05
+365/85 R20,365,0.85,20,1128.5,22.5,3.05
+375/45 R22.5,375,0.45,22.5,909,11.2,3.03
+375/50 R22.5,375,0.5,22.5,946.5,13,3.03
+375/90 R22.5,375,0.9,22.5,1246.5,33.8,3.05
+385/55 R22.5,385,0.55,22.5,995,15.9,3.03
+385/65 R22.5,385,0.65,22.5,1072,19.2,3.03
+395/85 R20,395,0.85,20,1179.5,27.9,3.05
+425/65 R22.5,425,0.65,22.5,1124,22.5,3.03
+495/45 R22.5,495,0.45,22.5,1017,20.7,3.03
+525/65 R20.5,525,0.65,20.5,1203.2,35,3.03
diff --git a/VectoCore/VectoCoreTest/Models/Declaration/DeclarationDataTest.cs b/VectoCore/VectoCoreTest/Models/Declaration/DeclarationDataTest.cs
index d270790a3ba4458c7d273fd620fcb2ae98831e87..c0fc8ecd3c58d7157fe22b47213047fbfef32769 100644
--- a/VectoCore/VectoCoreTest/Models/Declaration/DeclarationDataTest.cs
+++ b/VectoCore/VectoCoreTest/Models/Declaration/DeclarationDataTest.cs
@@ -54,14 +54,15 @@ namespace TUGraz.VectoCore.Tests.Models.Declaration
 		public const double Tolerance = 0.0001;
 		public readonly MissionType[] Missions = EnumHelper.GetValues<MissionType>().ToArray();
 
-		[TestCase("285/70 R19.5", 7.9, 0.8943, "b")]
-		public void WheelDataTest(string wheels, double intertia, double dynamicRadius, string sizeClass)
+		[TestCase("285/70 R19.5", 7.9, 0.8943, 3.03)]
+		public void WheelDataTest(string wheels, double inertia, double dynamicRadius, string sizeClass,
+			double circumferenceFactor)
 		{
 			var tmp = DeclarationData.Wheels.Lookup(wheels);
 
-			Assert.AreEqual(intertia, tmp.Inertia.Value(), Tolerance);
+			Assert.AreEqual(inertia, tmp.Inertia.Value(), Tolerance);
 			Assert.AreEqual(dynamicRadius, tmp.DynamicTyreRadius.Value(), Tolerance);
-			Assert.AreEqual(sizeClass, tmp.SizeClass);
+			Assert.AreEqual(circumferenceFactor, tmp.CircumferenceFactor, Tolerance);
 		}
 
 		[TestCase("15° DC Rims", 3.03, 3.05)]