diff --git a/include/hexagram/dial.h b/include/hexagram/dial.h
index 3e420e3..7597d58 100644
--- a/include/hexagram/dial.h
+++ b/include/hexagram/dial.h
@@ -47,9 +47,8 @@ int hexagram_dial_draw_legend(hexagram_dial *dial,
 
 int hexagram_dial_draw_mark(hexagram_dial *dial,
                             cairo_t *cr,
-                            double min_radius,
-                            double max_radius,
-                            double value);
+                            double value,
+                            int large);
 
 int hexagram_dial_draw_needle(hexagram_dial *dial, cairo_t *cr, double value);
 
diff --git a/src/dial.c b/src/dial.c
index fb64c25..0dad80f 100644
--- a/src/dial.c
+++ b/src/dial.c
@@ -20,6 +20,14 @@
 #define DIAL_RADIUS_NEEDLE_BOTTOM_MIN 0.8
 #define DIAL_RADIUS_NEEDLE_BOTTOM_MAX 0.9
 
+#define DIAL_RADIUS_MARK_MAIN_MIN       0.82
+#define DIAL_RADIUS_MARK_MAIN_MIN_LARGE 0.80
+#define DIAL_RADIUS_MARK_MAIN_MAX       0.87
+
+#define DIAL_RADIUS_MARK_BOTTOM_MIN       0.84
+#define DIAL_RADIUS_MARK_BOTTOM_MIN_LARGE 0.82
+#define DIAL_RADIUS_MARK_BOTTOM_MAX       0.87
+
 static inline double _min(double a, double b) {
     return a < b?
            a: b;
@@ -228,10 +236,23 @@ int hexagram_dial_draw_legend(hexagram_dial *dial,
 
 int hexagram_dial_draw_mark(hexagram_dial *dial,
                             cairo_t *cr,
-                            double min_radius,
-                            double max_radius,
-                            double value) {
+                            double value,
+                            int large) {
     double angle = hexagram_dial_angle(dial, value);
+    double min_radius,
+           max_radius;
+
+    if (dial->type == HEXAGRAM_DIAL_MAIN) {
+        min_radius = large? DIAL_RADIUS_MARK_MAIN_MIN_LARGE:
+                            DIAL_RADIUS_MARK_MAIN_MIN;
+
+        max_radius = DIAL_RADIUS_MARK_MAIN_MAX;
+    } else {
+        min_radius = large? DIAL_RADIUS_MARK_BOTTOM_MIN_LARGE:
+                            DIAL_RADIUS_MARK_BOTTOM_MIN;
+
+        max_radius = DIAL_RADIUS_MARK_BOTTOM_MAX;
+    }
 
     cairo_move_to(cr,
                   dial->gauge.x + min_radius * dial->radius * cos(angle),
diff --git a/src/fuel.c b/src/fuel.c
index e112baf..e963067 100644
--- a/src/fuel.c
+++ b/src/fuel.c
@@ -39,20 +39,19 @@ static int draw_bg(hexagram_gauge *gauge, cairo_t *cr) {
     cairo_set_line_width(cr, 6.0);
 
     for (level=0; level<=LEVEL_MAX; level++) {
-        double min_radius;
+        int large = 0;
 
         if (level < 2) {
-            min_radius = 0.84;
             cairo_set_source_rgb(cr, 1, 0, 0);
         } else if (level < 4) {
-            min_radius = 0.82;
+            large = 1;
             cairo_set_source_rgb(cr, 1, 0, 0);
         } else {
-            min_radius = 0.82;
+            large = 1;
             cairo_set_source_rgb(cr, 1, 1, 1);
         }
 
-        hexagram_dial_draw_mark(&fuel->dial, cr, min_radius, 0.87, level);
+        hexagram_dial_draw_mark(&fuel->dial, cr, level, large);
     }
 
     return 0;
diff --git a/src/speedo.c b/src/speedo.c
index eadda48..0b004b0 100644
--- a/src/speedo.c
+++ b/src/speedo.c
@@ -54,10 +54,10 @@ static int draw_bg(hexagram_gauge *gauge, cairo_t *cr) {
     cairo_set_source_rgb(cr, 1, 1, 1);
 
     for (speed=0; speed<=(int)speedo->dial.max_value; speed += 5) {
-        double min_radius = speed % 10 == 0? 0.81: 0.82;
+        int large = speed % 10 == 0? 1: 0;
 
-        cairo_set_line_width(cr, speed % 10 == 0? 6.0: 2.0);
-        hexagram_dial_draw_mark(&speedo->dial, cr, min_radius, 0.87, (double)speed);
+        cairo_set_line_width(cr, large? 6.0: 2.0);
+        hexagram_dial_draw_mark(&speedo->dial, cr, (double)speed, large);
     }
 
     for (speed=0; speed<=(int)speedo->dial.max_value; speed += 20) {
diff --git a/src/tacho.c b/src/tacho.c
index 7a6f584..0bdd15b 100644
--- a/src/tacho.c
+++ b/src/tacho.c
@@ -30,15 +30,15 @@ static int draw_bg(hexagram_gauge *gauge, cairo_t *cr) {
     cairo_set_source_rgb(cr, 1, 1, 1);
 
     for (rpm=0; rpm<=(int)tacho->dial.max_value; rpm+=TACHO_INTERVAL_MARK) {
-        double min_radius = (rpm % TACHO_INTERVAL_LEGEND) == 0? 0.81: 0.82;
+        int large = (rpm % TACHO_INTERVAL_LEGEND) == 0? 1: 0;
 
         if (rpm >= tacho->redline) {
             cairo_set_source_rgb(cr, 0.6, 0.1, 0.1);
         }
 
-        cairo_set_line_width(cr, (rpm % TACHO_INTERVAL_LEGEND) == 0? 6.0: 2.0);
+        cairo_set_line_width(cr, large? 6.0: 2.0);
 
-        hexagram_dial_draw_mark(&tacho->dial, cr, min_radius, 0.87, rpm);
+        hexagram_dial_draw_mark(&tacho->dial, cr, rpm, large);
     }
 
     cairo_set_source_rgb(cr, 1, 1, 1);
diff --git a/src/thermo.c b/src/thermo.c
index 5a69c2b..9a5bd02 100644
--- a/src/thermo.c
+++ b/src/thermo.c
@@ -49,7 +49,7 @@ static int draw_bg(hexagram_gauge *gauge, cairo_t *cr) {
             cairo_set_source_rgb(cr, 1, 1, 1);
         }
 
-        hexagram_dial_draw_mark(&thermo->dial, cr, 0.83, 0.87, level);
+        hexagram_dial_draw_mark(&thermo->dial, cr, level, 1);
 
         level += incr;
     }