diff --git a/aircraft_cmd.c b/aircraft_cmd.c
index b351fca6fd..691005349d 100644
--- a/aircraft_cmd.c
+++ b/aircraft_cmd.c
@@ -504,32 +504,38 @@ int32 CmdChangeAircraftServiceInt(int x, int y, uint32 flags, uint32 p1, uint32
 	return 0;
 }
 
-// p1 = vehicle
-// p2 = new cargo type(0xFF)
-// p2 = skip check for stopped in hanger (0x0100)
+/** Refits an aircraft to the specified cargo type.
+ * @param x,y unused
+ * @param p1 vehicle ID of the aircraft to refit
+ * @param p2 various bitstuffed elements
+ * - p2 = (bit 0-7) - the new cargo type to refit to (p2 & 0xFF)
+ * - p2 = (bit 8)   - skip check for stopped in hangar, used by autoreplace (p2 & 0x100)
+ * @todo p2 bit8 check <b>NEEDS TO GO</b>
+ */
 int32 CmdRefitAircraft(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 {
-	Vehicle *v,*u;
+	Vehicle *v;
 	int pass, mail;
 	int32 cost;
-	byte SkipStoppedInHangerCheck = (p2 & 0x100) >> 8; //excludes the cargo value
-	byte new_cargo_type = p2 & 0xFF; //gets the cargo number
-	AircraftVehicleInfo *avi;
+	bool SkipStoppedInHangerCheck = !!HASBIT(p2, 8); // XXX - needs to go, yes?
+	CargoID new_cid = p2 & 0xFF; //gets the cargo number
+	const AircraftVehicleInfo *avi;
 
 	if (!IsVehicleIndex(p1)) return CMD_ERROR;
 
 	v = GetVehicle(p1);
 
-	if (v->type != VEH_Aircraft) return CMD_ERROR;
+	if (v->type != VEH_Aircraft || !CheckOwnership(v->owner)) return CMD_ERROR;
+	if (!SkipStoppedInHangerCheck && !CheckStoppedInHangar(v)) return_cmd_error(STR_A01B_AIRCRAFT_MUST_BE_STOPPED);
 
 	avi = AircraftVehInfo(v->engine_type);
 
-	if (!CheckOwnership(v->owner) || (!CheckStoppedInHangar(v) && !(SkipStoppedInHangerCheck)))
-		return CMD_ERROR;
+	/* Check cargo */
+	if (new_cid > NUM_CARGO || !CanRefitTo(v, new_cid)) return CMD_ERROR;
 
 	SET_EXPENSES_TYPE(EXPENSES_AIRCRAFT_RUN);
 
-	switch (new_cargo_type) {
+	switch (new_cid) {
 		case CT_PASSENGERS:
 			pass = avi->passenger_capacity;
 			break;
@@ -548,24 +554,22 @@ int32 CmdRefitAircraft(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	_aircraft_refit_capacity = pass;
 
 	cost = 0;
-	if (IS_HUMAN_PLAYER(v->owner) && new_cargo_type != v->cargo_type) {
+	if (IS_HUMAN_PLAYER(v->owner) && new_cid != v->cargo_type) {
 		cost = _price.aircraft_base >> 7;
 	}
 
 	if (flags & DC_EXEC) {
+		Vehicle *u;
 		v->cargo_cap = pass;
 
 		u = v->next;
-		mail = avi->mail_capacity;
-		if (new_cargo_type != CT_PASSENGERS) {
-			mail = 0;
-		}
+		mail = (new_cid != CT_PASSENGERS) ? 0 : avi->mail_capacity;
 		u->cargo_cap = mail;
 		//autorefitted planes wants to keep the cargo
 		//it will be checked if the cargo is valid in CmdReplaceVehicle
 		if (!(SkipStoppedInHangerCheck))
 			v->cargo_count = u->cargo_count = 0;
-		v->cargo_type = new_cargo_type;
+		v->cargo_type = new_cid;
 		InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
 	}
 
diff --git a/aircraft_gui.c b/aircraft_gui.c
index 60502ad33e..a263813bee 100644
--- a/aircraft_gui.c
+++ b/aircraft_gui.c
@@ -205,64 +205,11 @@ static void ShowBuildAircraftWindow(uint tile)
 	}
 }
 
-#define MAX_REFIT 0xFF
-
-const byte _aircraft_refit_normal[] = {
-	CT_PASSENGERS,
-	CT_MAIL,
-	CT_GOODS,
-	CT_VALUABLES,
-	MAX_REFIT
-};
-
-const byte _aircraft_refit_arctic[] = {
-	CT_PASSENGERS,
-	CT_MAIL,
-	CT_GOODS,
-	CT_FOOD,
-	MAX_REFIT
-};
-
-const byte _aircraft_refit_desert[] = {
-	CT_PASSENGERS,
-	CT_MAIL,
-	CT_FRUIT,
-	CT_GOODS,
-	CT_DIAMONDS,
-	MAX_REFIT
-};
-
-const byte _aircraft_refit_candy[] = {
-	CT_PASSENGERS,
-	CT_SUGAR,
-	CT_TOYS,
-	CT_CANDY,
-	CT_COLA,
-	CT_COTTON_CANDY,
-	CT_BUBBLES,
-	CT_TOFFEE,
-	CT_BATTERIES,
-	CT_PLASTIC,
-	CT_FIZZY_DRINKS,
-	MAX_REFIT
-};
-
-const byte * const _aircraft_refit_types[4] = {
-	_aircraft_refit_normal, _aircraft_refit_arctic, _aircraft_refit_desert, _aircraft_refit_candy
-};
-
-#undef MAX_REFIT
-
 static void AircraftRefitWndProc(Window *w, WindowEvent *e)
 {
-	switch(e->event) {
+	switch (e->event) {
 	case WE_PAINT: {
-		Vehicle *v = GetVehicle(w->window_number);
-		const byte *b;
-		int sel;
-		int x,y;
-		byte color;
-		int cargo;
+		const Vehicle *v = GetVehicle(w->window_number);
 
 		SetDParam(0, v->string_id);
 		SetDParam(1, v->unitnumber);
@@ -271,72 +218,31 @@ static void AircraftRefitWndProc(Window *w, WindowEvent *e)
 		DrawString(1, 15, STR_A040_SELECT_CARGO_TYPE_TO_CARRY, 0);
 
 		/* TODO: Support for custom GRFSpecial-specified refitting! --pasky */
+		WP(w,refit_d).cargo = DrawVehicleRefitWindow(v, WP(w, refit_d).sel);
 
-		cargo = -1;
-		x = 6;
-		y = 25;
-		sel = WP(w,refit_d).sel;
-
-#define show_cargo(ctype) { \
-		color = 16; \
-		if (sel == 0) { \
-			cargo = ctype; \
-			color = 12; \
-		} \
-		sel--; \
-		DrawString(x, y, _cargoc.names_s[ctype], color); \
-		y += 10; \
-		}
-
-		if (_engine_refit_masks[v->engine_type]) {
-			uint32 mask = _engine_refit_masks[v->engine_type];
-			int cid = 0;
-
-			for (; mask; mask >>= 1, cid++) {
-				if (!(mask & 1)) // not this cid
-					continue;
-				if (!(_local_cargo_id_landscape[cid] & (1 << _opt.landscape))) // not in this landscape
-					continue;
-
-				show_cargo(_local_cargo_id_ctype[cid]);
-			}
-
-		} else { // generic refit list
-			b = _aircraft_refit_types[_opt.landscape];
-			do {
-				show_cargo(*b);
-			} while (*++b != 0xFF);
-		}
-
-#undef show_cargo
-
-		WP(w,refit_d).cargo = cargo;
-
-		if (cargo != -1) {
-			int32 cost = DoCommandByTile(v->tile, v->index, cargo, DC_QUERY_COST, CMD_REFIT_AIRCRAFT);
-			if (cost != CMD_ERROR) {
+		if (WP(w,refit_d).cargo != CT_INVALID) {
+			int32 cost = DoCommandByTile(v->tile, v->index, WP(w,refit_d).cargo, DC_QUERY_COST, CMD_REFIT_AIRCRAFT);
+			if (!CmdFailed(cost)) {
 				SetDParam(2, cost);
-				SetDParam(0, _cargoc.names_long_p[cargo]);
+				SetDParam(0, _cargoc.names_long_p[WP(w,refit_d).cargo]);
 				SetDParam(1, _aircraft_refit_capacity);
 				DrawString(1, 137, STR_A041_NEW_CAPACITY_COST_OF_REFIT, 0);
 			}
 		}
-
-		break;
-	}
+	}	break;
 
 	case WE_CLICK:
 		switch(e->click.widget) {
 		case 2: { /* listbox */
-				int y = e->click.pt.y - 25;
-				if (y >= 0) {
-					WP(w,refit_d).sel = y / 10;
-					SetWindowDirty(w);
-				}
-			} break;
+			int y = e->click.pt.y - 25;
+			if (y >= 0) {
+				WP(w,refit_d).sel = y / 10;
+				SetWindowDirty(w);
+			}
+		} break;
 		case 4: /* refit button */
-			if (WP(w,refit_d).cargo != 0xFF) {
-				Vehicle *v = GetVehicle(w->window_number);
+			if (WP(w,refit_d).cargo != CT_INVALID) {
+				const Vehicle *v = GetVehicle(w->window_number);
 				if (DoCommandP(v->tile, v->index, WP(w,refit_d).cargo, NULL, CMD_REFIT_AIRCRAFT | CMD_MSG(STR_A042_CAN_T_REFIT_AIRCRAFT)))
 					DeleteWindow(w);
 			}
diff --git a/command.c b/command.c
index 67fbb05f03..7eae3c4fdd 100644
--- a/command.c
+++ b/command.c
@@ -229,7 +229,7 @@ static CommandProc * const _command_proc_table[] = {
 	CmdBuildAircraft,							/* 61 */
 	CmdSendAircraftToHangar,			/* 62 */
 	CmdChangeAircraftServiceInt,	/* 63 */
-	CmdRefitAircraft,							/* 64 <-- REFIT: Hackykid */
+	CmdRefitAircraft,							/* 64 */
 
 	CmdPlaceSign,									/* 65 */
 	CmdRenameSign,								/* 66 */
@@ -263,7 +263,7 @@ static CommandProc * const _command_proc_table[] = {
 	CmdBuildShip,									/* 88 */
 	CmdSendShipToDepot,						/* 89 */
 	CmdChangeShipServiceInt,			/* 90 */
-	CmdRefitShip,									/* 91 <-- REFIT: Hackykid */
+	CmdRefitShip,									/* 91 */
 
 	NULL,            							/* 92 */
 	NULL,                         /* 93 */
@@ -284,7 +284,7 @@ static CommandProc * const _command_proc_table[] = {
 
 	CmdLevelLand,									/* 105 */
 
-	CmdRefitRailVehicle,					/* 106 <-- REFIT: Hackykid */
+	CmdRefitRailVehicle,					/* 106 */
 	CmdRestoreOrderIndex,					/* 107 */
 	CmdBuildLock,									/* 108 */
 	NULL,           							/* 109 */
diff --git a/engine.c b/engine.c
index 64d2c826a2..bcbb87438a 100644
--- a/engine.c
+++ b/engine.c
@@ -20,34 +20,74 @@ enum {
 	ENGINE_PREVIEWING = 4,
 };
 
-/* This maps per-landscape cargo ids to globally unique cargo ids usable ie. in
- * the custom GRF files. It is basically just a transcribed table from
- * TTDPatch's newgrf.txt. */
-byte _global_cargo_id[NUM_LANDSCAPE][NUM_CARGO] = {
-	/* LT_NORMAL */ {  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 12 },
-	/* LT_HILLY */  {  0,  1,  2,  3,  4,  5,  6,  7, 28, 11, 10, 12 },
-	/* LT_DESERT */ {  0, 16,  2,  3, 13,  5,  6,  7, 14, 15, 10, 12 },
-	/* LT_CANDY */  {  0, 17,  2, 18, 19, 20, 21, 22, 23, 24, 25, 26 },
-	// 27 is paper in temperate climate in TTDPatch
-	// Following can be renumbered:
-	// 29 is the default cargo for the purpose of spritesets
-	// 30 is the purchase list image (the equivalent of 0xff) for the purpose of spritesets
+/** TRANSLATE FROM LOCAL CARGO TO GLOBAL CARGO ID'S.
+ * This maps the per-landscape cargo ID's to globally unique cargo ID's usable ie. in
+ * the custom GRF  files. It is basically just a transcribed table from TTDPatch's newgrf.txt.
+ */
+const CargoID _global_cargo_id[NUM_LANDSCAPE][NUM_CARGO] = {
+	/* LT_NORMAL */ {GC_PASSENGERS, GC_COAL,  GC_MAIL, GC_OIL, GC_LIVESTOCK, GC_GOODS, GC_GRAIN, GC_WOOD, GC_IRON_ORE,    GC_STEEL,  GC_VALUABLES, GC_PAPER_TEMP},
+	/* LT_HILLY */  {GC_PASSENGERS, GC_COAL,  GC_MAIL, GC_OIL, GC_LIVESTOCK, GC_GOODS, GC_GRAIN, GC_WOOD, GC_INVALID,     GC_PAPER,  GC_VALUABLES, GC_FOOD },
+	/* LT_DESERT */ {GC_PASSENGERS, GC_RUBBER,GC_MAIL, GC_OIL, GC_FRUIT,     GC_GOODS, GC_GRAIN, GC_WOOD, GC_COPPER_ORE,  GC_WATER,  GC_VALUABLES, GC_FOOD },
+	/* LT_CANDY */  {GC_PASSENGERS, GC_SUGAR, GC_MAIL, GC_TOYS,GC_BATTERIES, GC_CANDY, GC_TOFFEE,GC_COLA, GC_COTTON_CANDY,GC_BUBBLES,GC_PLASTIC,   GC_FIZZY_DRINKS },
+	/**
+	 * - GC_INVALID (255) means that  cargo is not available for that climate
+	 * - GC_PAPER_TEMP (27) is paper in  temperate climate in TTDPatch
+	 * Following can  be renumbered:
+	 * - GC_DEFAULT (29) is the defa ult cargo for the purpose of spritesets
+	 * - GC_PURCHASE (30) is the purchase list image (the equivalent of 0xff) for the purpose of spritesets
+	 */
 };
 
-/* These two arrays provide a reverse mapping. */
-byte _local_cargo_id_ctype[NUM_CID] = {
-	CT_PASSENGERS, CT_COAL, CT_MAIL, CT_OIL, CT_LIVESTOCK, CT_GOODS, CT_GRAIN, CT_WOOD, // 0-7
-	CT_IRON_ORE, CT_STEEL, CT_VALUABLES, CT_PAPER, CT_FOOD, CT_FRUIT, CT_COPPER_ORE, CT_WATER, // 8-15
-	CT_RUBBER, CT_SUGAR, CT_TOYS, CT_BATTERIES, CT_CANDY, CT_TOFFEE, CT_COLA, CT_COTTON_CANDY, // 16-23
-	CT_BUBBLES, CT_PLASTIC, CT_FIZZY_DRINKS, CT_PAPER /* unsup. */, CT_HILLY_UNUSED // 24-28
+/** BEGIN --- TRANSLATE FROM GLOBAL CARGO TO LOCAL CARGO ID'S **/
+/** Map global cargo ID's to local-cargo ID's */
+const CargoID _local_cargo_id_ctype[NUM_GLOBAL_CID] = {
+	CT_PASSENGERS,CT_COAL,   CT_MAIL,        CT_OIL,      CT_LIVESTOCK,CT_GOODS,  CT_GRAIN,      CT_WOOD,         /*  0- 7 */
+	CT_IRON_ORE,  CT_STEEL,  CT_VALUABLES,   CT_PAPER,    CT_FOOD,     CT_FRUIT,  CT_COPPER_ORE, CT_WATER,        /*  8-15 */
+	CT_RUBBER,    CT_SUGAR,  CT_TOYS,        CT_BATTERIES,CT_CANDY,    CT_TOFFEE, CT_COLA,       CT_COTTON_CANDY, /* 16-23 */
+	CT_BUBBLES,   CT_PLASTIC,CT_FIZZY_DRINKS,CT_PAPER     /* unsup. */,CT_HILLY_UNUSED,                           /* 24-28 */
+	CT_INVALID,   CT_INVALID                                                                                      /* 29-30 */
 };
 
-/* LT'th bit is set of the particular landscape if cargo available there.
- * 1: LT_NORMAL, 2: LT_HILLY, 4: LT_DESERT, 8: LT_CANDY */
-byte _local_cargo_id_landscape[NUM_CID] = {
-	15, 3, 15, 7, 3, 7, 7, 7, 1, 1, 7, 2, 7, // 0-12
-	4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 1, 2, // 13-28
+#define MC(cargo) (1 << cargo)
+/** Bitmasked value where the global cargo ID is available in landscape
+ * 0: LT_NORMAL, 1: LT_HILLY, 2: LT_DESERT, 3: LT_CANDY */
+const uint32 _landscape_global_cargo_mask[NUM_LANDSCAPE] =
+{ /* LT_NORMAL: temperate */
+	MC(GC_PASSENGERS)|MC(GC_COAL)|MC(GC_MAIL)|MC(GC_OIL)|MC(GC_LIVESTOCK)|MC(GC_GOODS)|MC(GC_GRAIN)|MC(GC_WOOD)|
+	MC(GC_IRON_ORE)|MC(GC_STEEL)|MC(GC_VALUABLES)|MC(GC_FOOD)|MC(GC_UNDEFINED),
+	/* LT_HILLY: arctic */
+	MC(GC_PASSENGERS)|MC(GC_COAL)|MC(GC_MAIL)|MC(GC_OIL)|MC(GC_LIVESTOCK)|MC(GC_GOODS)|
+	MC(GC_GRAIN)|MC(GC_WOOD)|MC(GC_VALUABLES)|MC(GC_PAPER)|MC(GC_FOOD)|MC(GC_UNDEFINED),
+	/* LT_DESERT: rainforest/desert */
+	MC(GC_PASSENGERS)|MC(GC_MAIL)|MC(GC_OIL)|MC(GC_GOODS)|MC(GC_GRAIN)|MC(GC_WOOD)|
+	MC(GC_VALUABLES)|MC(GC_FOOD)|MC(GC_FRUIT)|MC(GC_COPPER_ORE)|MC(GC_WATER)|MC(GC_RUBBER),
+	/* LT_CANDY: toyland */
+	MC(GC_PASSENGERS)|MC(GC_MAIL)|MC(GC_SUGAR)|MC(GC_TOYS)|MC(GC_BATTERIES)|MC(GC_CANDY)|
+	MC(GC_TOFFEE)|MC(GC_COLA)|MC(GC_COTTON_CANDY)|MC(GC_BUBBLES)|MC(GC_PLASTIC)|MC(GC_FIZZY_DRINKS)
 };
+/** END   --- TRANSLATE FROM GLOBAL CARGO TO LOCAL CARGO ID'S **/
+
+/** Bitmasked values of what type of cargo is refittable for the given vehicle-type.
+ * This coupled with the landscape information (_landscape_global_cargo_mask) gives
+ * us exactly what is refittable and what is not */
+const uint32 _default_refitmasks[NUM_VEHICLE_TYPES] = {
+	/* Trains */
+	MC(GC_PASSENGERS)|MC(GC_COAL)|MC(GC_MAIL)|MC(GC_LIVESTOCK)|MC(GC_GOODS)|MC(GC_GRAIN)|MC(GC_WOOD)|MC(GC_IRON_ORE)|
+	MC(GC_STEEL)|MC(GC_VALUABLES)|MC(GC_PAPER)|MC(GC_FOOD)|MC(GC_FRUIT)|MC(GC_COPPER_ORE)|MC(GC_WATER)|MC(GC_SUGAR)|
+	MC(GC_TOYS)|MC(GC_CANDY)|MC(GC_TOFFEE)|MC(GC_COLA)|MC(GC_COTTON_CANDY)|MC(GC_BUBBLES)|MC(GC_PLASTIC)|MC(GC_FIZZY_DRINKS),
+	/* Road vehicles (not refittable by default) */
+	0,
+	/* Ships */
+	MC(GC_COAL)|MC(GC_MAIL)|MC(GC_LIVESTOCK)|MC(GC_GOODS)|MC(GC_GRAIN)|MC(GC_WOOD)|MC(GC_IRON_ORE)|MC(GC_STEEL)|MC(GC_VALUABLES)|
+	MC(GC_PAPER)|MC(GC_FOOD)|MC(GC_FRUIT)|MC(GC_COPPER_ORE)|MC(GC_WATER)|MC(GC_RUBBER)|MC(GC_SUGAR)|MC(GC_TOYS)|MC(GC_BATTERIES)|
+	MC(GC_CANDY)|MC(GC_TOFFEE)|MC(GC_COLA)|MC(GC_COTTON_CANDY)|MC(GC_BUBBLES)|MC(GC_PLASTIC)|MC(GC_FIZZY_DRINKS),
+	/* Aircraft */
+	MC(GC_PASSENGERS)|MC(GC_MAIL)|MC(GC_GOODS)|MC(GC_VALUABLES)|MC(GC_FOOD)|MC(GC_FRUIT)|MC(GC_SUGAR)|MC(GC_TOYS)|
+	MC(GC_BATTERIES)|MC(GC_CANDY)|MC(GC_TOFFEE)|MC(GC_COLA)|MC(GC_COTTON_CANDY)|MC(GC_BUBBLES)|MC(GC_PLASTIC)|MC(GC_FIZZY_DRINKS),
+	/* Special/Disaster */
+	0,0
+};
+#undef MC
 
 void ShowEnginePreviewWindow(int engine);
 
@@ -267,7 +307,7 @@ byte _engine_original_sprites[TOTAL_NUM_ENGINES];
 // (It isn't and shouldn't be like this in the GRF files since new cargo types
 // may appear in future - however it's more convenient to store it like this in
 // memory. --pasky)
-static SpriteGroup _engine_custom_sprites[TOTAL_NUM_ENGINES][NUM_CID];
+static SpriteGroup _engine_custom_sprites[TOTAL_NUM_ENGINES][NUM_GLOBAL_CID];
 
 void SetCustomEngineSprites(byte engine, byte cargo, SpriteGroup *group)
 {
@@ -462,10 +502,11 @@ static RealSpriteGroup* ResolveVehicleSpriteGroup(SpriteGroup *spritegroup,
 static SpriteGroup *GetVehicleSpriteGroup(byte engine, const Vehicle *v)
 {
 	SpriteGroup *group;
-	byte cargo = CID_PURCHASE;
+	byte cargo = GC_PURCHASE;
 
 	if (v != NULL) {
 		cargo = _global_cargo_id[_opt.landscape][v->cargo_type];
+		assert(cargo != GC_INVALID);
 	}
 
 	group = &_engine_custom_sprites[engine][cargo];
@@ -483,7 +524,7 @@ int GetCustomEngineSprite(byte engine, const Vehicle *v, byte direction)
 {
 	SpriteGroup *group;
 	RealSpriteGroup *rsg;
-	byte cargo = CID_PURCHASE;
+	byte cargo = GC_PURCHASE;
 	byte loaded = 0;
 	bool in_motion = 0;
 	int totalsets, spriteset;
@@ -493,6 +534,8 @@ int GetCustomEngineSprite(byte engine, const Vehicle *v, byte direction)
 		int capacity = v->cargo_cap;
 
 		cargo = _global_cargo_id[_opt.landscape][v->cargo_type];
+		assert(cargo != GC_INVALID);
+
 		if (capacity == 0) capacity = 1;
 		loaded = (v->cargo_count * 100) / capacity;
 		in_motion = (v->cur_speed != 0);
diff --git a/engine.h b/engine.h
index cbb860dc98..b588478fec 100644
--- a/engine.h
+++ b/engine.h
@@ -79,23 +79,56 @@ enum {
 	RVI_WAGON = 2,
 };
 
+enum {
+	NUM_VEHICLE_TYPES = 6
+};
 
 void AddTypeToEngines(void);
 void StartupEngines(void);
 
-
-extern byte _global_cargo_id[NUM_LANDSCAPE][NUM_CARGO];
-enum {
-	CID_DEFAULT = 29,
-	CID_PURCHASE = 30,
-	NUM_CID = 31,
+enum GlobalCargo {
+	GC_PASSENGERS   =   0,
+	GC_COAL         =   1,
+	GC_MAIL         =   2,
+	GC_OIL          =   3,
+	GC_LIVESTOCK    =   4,
+	GC_GOODS        =   5,
+	GC_GRAIN        =   6, // GC_WHEAT / GC_MAIZE
+	GC_WOOD         =   7,
+	GC_IRON_ORE     =   8,
+	GC_STEEL        =   9,
+	GC_VALUABLES    =  10, // GC_GOLD / GC_DIAMONDS
+	GC_PAPER        =  11,
+	GC_FOOD         =  12,
+	GC_FRUIT        =  13,
+	GC_COPPER_ORE   =  14,
+	GC_WATER        =  15,
+	GC_RUBBER       =  16,
+	GC_SUGAR        =  17,
+	GC_TOYS         =  18,
+	GC_BATTERIES    =  19,
+	GC_CANDY        =  20,
+	GC_TOFFEE       =  21,
+	GC_COLA         =  22,
+	GC_COTTON_CANDY =  23,
+	GC_BUBBLES      =  24,
+	GC_PLASTIC      =  25,
+	GC_FIZZY_DRINKS =  26,
+	GC_PAPER_TEMP   =  27,
+	GC_UNDEFINED    =  28, // undefined; unused slot in arctic climate
+	GC_DEFAULT      =  29,
+	GC_PURCHASE     =  30,
+	GC_INVALID      = 255,
+	NUM_GLOBAL_CID  =  31
 };
-extern byte _local_cargo_id_ctype[NUM_CID];
-extern byte _local_cargo_id_landscape[NUM_CID];
 
-extern uint32 _engine_refit_masks[256];
+VARDEF const uint32 _default_refitmasks[NUM_VEHICLE_TYPES];
+VARDEF const CargoID _global_cargo_id[NUM_LANDSCAPE][NUM_CARGO];
+VARDEF const uint32 _landscape_global_cargo_mask[NUM_LANDSCAPE];
+VARDEF const CargoID _local_cargo_id_ctype[NUM_GLOBAL_CID];
 
-extern byte _engine_original_sprites[256];
+VARDEF uint32 _engine_refit_masks[256];
+VARDEF byte _engine_original_sprites[256];
 void SetWagonOverrideSprites(byte engine, struct SpriteGroup *group, byte *train_id, int trains);
 void SetCustomEngineSprites(byte engine, byte cargo, struct SpriteGroup *group);
 // loaded is in percents, overriding_engine 0xffff is none
diff --git a/lang/english.txt b/lang/english.txt
index c15eb9b78e..892c6fae1c 100644
--- a/lang/english.txt
+++ b/lang/english.txt
@@ -2445,6 +2445,7 @@ STR_882C_BUILT_VALUE                                            :{LTBLUE}{STRING
 STR_882D_VALUE                                                  :{LTBLUE}{STRING}{BLACK}   Value: {LTBLUE}{CURRENCY}
 STR_882E                                                        :{WHITE}{STRING}
 STR_882F_LOADING_UNLOADING                                      :{LTBLUE}Loading / Unloading
+STR_TRAIN_MUST_BE_STOPPED                                       :{WHITE}Train must be stopped inside depot
 STR_8830_CAN_T_SEND_TRAIN_TO_DEPOT                              :{WHITE}Can't send train to depot...
 STR_8831_NO_MORE_SPACE_FOR_ORDERS                               :{WHITE}No more space for orders
 STR_8832_TOO_MANY_ORDERS                                        :{WHITE}Too many orders
diff --git a/newgrf.c b/newgrf.c
index 30c5a8f064..3607326aad 100644
--- a/newgrf.c
+++ b/newgrf.c
@@ -1450,8 +1450,7 @@ static void NewVehicle_SpriteGroupMapping(byte *buf, int len)
 				return;
 			}
 
-			if (ctype == 0xFF)
-				ctype = CID_PURCHASE;
+			if (ctype == GC_INVALID) ctype = GC_PURCHASE;
 
 			if (wagover) {
 				// TODO: No multiple cargo types per vehicle yet. --pasky
@@ -1482,7 +1481,7 @@ static void NewVehicle_SpriteGroupMapping(byte *buf, int len)
 				// TODO: No multiple cargo types per vehicle yet. --pasky
 				SetWagonOverrideSprites(engine, &_cur_grffile->spritegroups[groupid], last_engines, last_engines_count);
 			} else {
-				SetCustomEngineSprites(engine, CID_DEFAULT, &_cur_grffile->spritegroups[groupid]);
+				SetCustomEngineSprites(engine, GC_DEFAULT, &_cur_grffile->spritegroups[groupid]);
 				last_engines[i] = engine;
 			}
 		}
diff --git a/ship_cmd.c b/ship_cmd.c
index 24d21fc472..b8190d6b7f 100644
--- a/ship_cmd.c
+++ b/ship_cmd.c
@@ -1067,36 +1067,39 @@ int32 CmdChangeShipServiceInt(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	return 0;
 }
 
-
-// p1 = vehicle
-// p2 = new cargo (0xFF)
-// p2 = skip check for stopped in hanger (0x0100)
+/** Refits a ship to the specified cargo type.
+ * @param x,y unused
+ * @param p1 vehicle ID of the ship to refit
+ * @param p2 various bitstuffed elements
+ * - p2 = (bit 0-7) - the new cargo type to refit to (p2 & 0xFF)
+ * - p2 = (bit 8)   - skip check for stopped in depot, used by autoreplace (p2 & 0x100)
+ * @todo p2 bit8 check <b>NEEDS TO GO</b>
+ */
 int32 CmdRefitShip(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 {
 	Vehicle *v;
 	int32 cost;
-	byte SkipStoppedInDepotCheck = (p2 & 0x100) >> 8; //excludes the cargo value
-
-	p2 = p2 & 0xFF;
+	CargoID new_cid = p2 & 0xFF; //gets the cargo number
+	bool SkipStoppedInDepotCheck = !!HASBIT(p2, 8); // XXX - needs to go, yes?
 
 	if (!IsVehicleIndex(p1)) return CMD_ERROR;
 
 	v = GetVehicle(p1);
 
-	if (v->type != VEH_Ship || !CheckOwnership(v->owner))
-		return CMD_ERROR;
-
-	if (!( SkipStoppedInDepotCheck )) {
-		if (!IsTileDepotType(v->tile, TRANSPORT_WATER) ||
-				!(v->vehstatus&VS_STOPPED) ||
-				v->u.ship.state != 0x80)
+	if (v->type != VEH_Ship || !CheckOwnership(v->owner)) return CMD_ERROR;
+	if (!SkipStoppedInDepotCheck) {
+		if (!IsTileDepotType(v->tile, TRANSPORT_WATER) || !(v->vehstatus&VS_STOPPED) || v->u.ship.state != 0x80)
 			return_cmd_error(STR_980B_SHIP_MUST_BE_STOPPED_IN);
-		}
+	}
+
+	/* Check cargo */
+	if (!ShipVehInfo(v->engine_type)->refittable) return CMD_ERROR;
+	if (new_cid > NUM_CARGO || !CanRefitTo(v, new_cid)) return CMD_ERROR;
 
 	SET_EXPENSES_TYPE(EXPENSES_SHIP_RUN);
 
 	cost = 0;
-	if (IS_HUMAN_PLAYER(v->owner) && (byte)p2 != v->cargo_type) {
+	if (IS_HUMAN_PLAYER(v->owner) && new_cid != v->cargo_type) {
 		cost = _price.ship_base >> 7;
 	}
 
@@ -1105,12 +1108,10 @@ int32 CmdRefitShip(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 		//it will be checked if the cargo is valid in CmdRenewVehicle
 		if (!(SkipStoppedInDepotCheck))
 			v->cargo_count = 0;
-		v->cargo_type = (byte)p2;
+		v->cargo_type = new_cid;
 		InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
 	}
 
 	return cost;
 
 }
-
-
diff --git a/ship_gui.c b/ship_gui.c
index c0cf59e103..1e1428de28 100644
--- a/ship_gui.c
+++ b/ship_gui.c
@@ -45,23 +45,11 @@ static void DrawShipImage(const Vehicle *v, int x, int y, VehicleID selection)
 	}
 }
 
-const byte _ship_refit_types[4][16] = {
-	{CT_MAIL, CT_COAL, CT_LIVESTOCK, CT_GOODS, CT_GRAIN, CT_WOOD, CT_IRON_ORE, CT_STEEL, CT_VALUABLES, 255},
-	{CT_MAIL, CT_COAL, CT_LIVESTOCK, CT_GOODS, CT_GRAIN, CT_WOOD, CT_PAPER, CT_FOOD, CT_VALUABLES, 255},
-	{CT_MAIL, CT_FRUIT, CT_GOODS, CT_COPPER_ORE, CT_GRAIN, CT_WOOD, CT_WATER, CT_VALUABLES, 255},
-	{CT_MAIL, CT_SUGAR, CT_TOYS, CT_CANDY, CT_COLA, CT_COTTON_CANDY, CT_BUBBLES, CT_TOFFEE, CT_BATTERIES, CT_PLASTIC, CT_FIZZY_DRINKS, 255},
-};
-
 static void ShipRefitWndProc(Window *w, WindowEvent *e)
 {
-	switch(e->event) {
+	switch (e->event) {
 	case WE_PAINT: {
-		Vehicle *v = GetVehicle(w->window_number);
-		const byte *b;
-		int sel;
-		int x,y;
-		byte color;
-		int cargo;
+		const Vehicle *v = GetVehicle(w->window_number);
 
 		SetDParam(0, v->string_id);
 		SetDParam(1, v->unitnumber);
@@ -69,71 +57,32 @@ static void ShipRefitWndProc(Window *w, WindowEvent *e)
 
 		DrawString(1, 15, STR_983F_SELECT_CARGO_TYPE_TO_CARRY, 0);
 
-		cargo = -1;
-		x = 6;
-		y = 25;
-		sel = WP(w,refit_d).sel;
+		/* TODO: Support for custom GRFSpecial-specified refitting! --pasky */
+		WP(w,refit_d).cargo = DrawVehicleRefitWindow(v, WP(w, refit_d).sel);;
 
-#define show_cargo(ctype) { \
-		color = 16; \
-		if (sel == 0) { \
-			cargo = ctype; \
-			color = 12; \
-		} \
-		sel--; \
-		DrawString(x, y, _cargoc.names_s[ctype], color); \
-		y += 10; \
-		}
-
-		if (_engine_refit_masks[v->engine_type]) {
-			uint32 mask = _engine_refit_masks[v->engine_type];
-			int cid = 0;
-
-			for (; mask; mask >>= 1, cid++) {
-				if (!(mask & 1)) // not this cid
-					continue;
-				if (!(_local_cargo_id_landscape[cid] & (1 << _opt.landscape))) // not in this landscape
-					continue;
-
-				show_cargo(_local_cargo_id_ctype[cid]);
-			}
-
-		} else { // generic refit list
-			b = _ship_refit_types[_opt.landscape];
-			do {
-				show_cargo(*b);
-			} while (*++b != 255);
-		}
-
-#undef show_cargo
-
-		WP(w,refit_d).cargo = cargo;
-
-		if (cargo != -1) {
-			int32 cost = DoCommandByTile(v->tile, v->index, cargo, 0, CMD_REFIT_SHIP);
-			if (cost != CMD_ERROR) {
+		if (WP(w,refit_d).cargo != CT_INVALID) {
+			int32 cost = DoCommandByTile(v->tile, v->index, WP(w,refit_d).cargo, DC_QUERY_COST, CMD_REFIT_SHIP);
+			if (!CmdFailed(cost)) {
 				SetDParam(2, cost);
-				SetDParam(0, _cargoc.names_long_p[cargo]);
+				SetDParam(0, _cargoc.names_long_p[WP(w,refit_d).cargo]);
 				SetDParam(1, v->cargo_cap);
 				DrawString(1, 137, STR_9840_NEW_CAPACITY_COST_OF_REFIT, 0);
 			}
 		}
-
-		break;
-	}
+	}	break;
 
 	case WE_CLICK:
 		switch(e->click.widget) {
 		case 2: { /* listbox */
-				int y = e->click.pt.y - 25;
-				if (y >= 0) {
-					WP(w,refit_d).sel = y / 10;
-					SetWindowDirty(w);
-				}
-			} break;
+			int y = e->click.pt.y - 25;
+			if (y >= 0) {
+				WP(w,refit_d).sel = y / 10;
+				SetWindowDirty(w);
+			}
+		} break;
 		case 4: /* refit button */
-			if (WP(w,refit_d).cargo != 0xFF) {
-				Vehicle *v = GetVehicle(w->window_number);
+			if (WP(w,refit_d).cargo != CT_INVALID) {
+				const Vehicle *v = GetVehicle(w->window_number);
 				if (DoCommandP(v->tile, v->index, WP(w,refit_d).cargo, NULL, CMD_REFIT_SHIP | CMD_MSG(STR_9841_CAN_T_REFIT_SHIP)))
 					DeleteWindow(w);
 			}
diff --git a/station.h b/station.h
index 08c3e01c0d..608688fc73 100644
--- a/station.h
+++ b/station.h
@@ -248,7 +248,7 @@ typedef struct StationSpec {
 	StationLayout **layouts;
 
 	/* Sprite offsets for renderdata->seq->image. spritegroup[0] is default
-	 * whilst spritegroup[1] is "CID_PURCHASE". */
+	 * whilst spritegroup[1] is "GC_PURCHASE". */
 	SpriteGroup spritegroup[2];
 } StationSpec;
 
diff --git a/train_cmd.c b/train_cmd.c
index 255ede1742..95770e4429 100644
--- a/train_cmd.c
+++ b/train_cmd.c
@@ -1282,25 +1282,31 @@ int32 CmdForceTrainProceed(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	return 0;
 }
 
-// p1 = vehicle to refit
-// p2 = new cargo (0xFF)
-// p2 = skip check for stopped in hanger (0x0100)
+/** Refits a train to the specified cargo type.
+ * @param x,y unused
+ * @param p1 vehicle ID of the train to refit
+ * @param p2 various bitstuffed elements
+ * - p2 = (bit 0-7) - the new cargo type to refit to (p2 & 0xFF)
+ * - p2 = (bit 8)   - skip check for stopped in depot, used by autoreplace (p2 & 0x100)
+ * @todo p2 bit8 check <b>NEEDS TO GO</b>
+ */
 int32 CmdRefitRailVehicle(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 {
 	Vehicle *v;
 	int32 cost;
 	uint num;
-
-	byte SkipStoppedInDepotCheck = (p2 & 0x100) >> 8;
-
-	p2 = p2 & 0xFF;
+	CargoID new_cid = p2 & 0xFF; //gets the cargo number
+	bool SkipStoppedInDepotCheck = !!HASBIT(p2, 8); // XXX - needs to go, yes?
 
 	if (!IsVehicleIndex(p1)) return CMD_ERROR;
 
 	v = GetVehicle(p1);
 
-	if (v->type != VEH_Train || !CheckOwnership(v->owner) || ((CheckTrainStoppedInDepot(v) < 0) && !(SkipStoppedInDepotCheck)))
-		return CMD_ERROR;
+	if (v->type != VEH_Train || !CheckOwnership(v->owner)) return CMD_ERROR;
+	if (!SkipStoppedInDepotCheck && CheckTrainStoppedInDepot(v) < 0) return_cmd_error(STR_TRAIN_MUST_BE_STOPPED);
+
+	/* Check cargo */
+	if (new_cid > NUM_CARGO) return CMD_ERROR;
 
 	SET_EXPENSES_TYPE(EXPENSES_TRAIN_RUN);
 
@@ -1311,17 +1317,17 @@ int32 CmdRefitRailVehicle(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 		/* XXX: We also refit all the attached wagons en-masse if they
 		 * can be refitted. This is how TTDPatch does it.  TODO: Have
 		 * some nice [Refit] button near each wagon. --pasky */
-		if ((!(RailVehInfo(v->engine_type)->flags & RVI_WAGON)
-		     || (_engine_refit_masks[v->engine_type] & (1 << p2)))
-		    && (byte) p2 != v->cargo_type && v->cargo_cap != 0) {
+		if (!CanRefitTo(v, new_cid)) continue;
+
+		if (new_cid != v->cargo_type && v->cargo_cap != 0) {
 			cost += (_price.build_railvehicle >> 8);
 			num += v->cargo_cap;
 			if (flags & DC_EXEC) {
-		//autorefitted train cars wants to keep the cargo
-		//it will be checked if the cargo is valid in CmdReplaceVehicle
+				//autorefitted train cars wants to keep the cargo
+				//it will be checked if the cargo is valid in CmdReplaceVehicle
 				if (!(SkipStoppedInDepotCheck))
 					v->cargo_count = 0;
-				v->cargo_type = (byte)p2;
+				v->cargo_type = new_cid;
 				InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
 			}
 		}
diff --git a/train_gui.c b/train_gui.c
index c6bcf66cdd..3cc68811f7 100644
--- a/train_gui.c
+++ b/train_gui.c
@@ -662,23 +662,11 @@ void ShowTrainDepotWindow(uint tile)
 	}
 }
 
-const byte _rail_vehicle_refit_types[4][16] = {
-	{ 0,1,2,4,5,6,7,8,9,10,0xFF },	// normal
-	{ 0,1,4,5,6,7,9,11,10,0xFF },		// arctic
-	{ 0,4,5,8,6,7,9,10,0xFF },			// desert
-	{ 0,1,3,5,7,8,9,6,4,10,11,0xFF }// candy
-};
-
 static void RailVehicleRefitWndProc(Window *w, WindowEvent *e)
 {
-	switch(e->event) {
+	switch (e->event) {
 	case WE_PAINT: {
-		Vehicle *v = GetVehicle(w->window_number);
-		const byte *b;
-		int sel;
-		int x,y;
-		byte color;
-		int cargo;
+		const Vehicle *v = GetVehicle(w->window_number);
 
 		SetDParam(0, v->string_id);
 		SetDParam(1, v->unitnumber);
@@ -686,57 +674,19 @@ static void RailVehicleRefitWndProc(Window *w, WindowEvent *e)
 
 		DrawString(1, 15, STR_983F_SELECT_CARGO_TYPE_TO_CARRY, 0);
 
-		cargo = -1;
-		x = 6;
-		y = 25;
-		sel = WP(w,refit_d).sel;
+		/* TODO: Support for custom GRFSpecial-specified refitting! --pasky */
+		WP(w,refit_d).cargo = DrawVehicleRefitWindow(v, WP(w, refit_d).sel);
 
-#define show_cargo(ctype) { \
-		color = 16; \
-		if (sel == 0) { \
-			cargo = ctype; \
-			color = 12; \
-		} \
-		sel--; \
-		DrawString(x, y, _cargoc.names_s[ctype], color); \
-		y += 10; \
-		}
-
-		if (_engine_refit_masks[v->engine_type]) {
-			uint32 mask = _engine_refit_masks[v->engine_type];
-			int cid = 0;
-
-			for (; mask; mask >>= 1, cid++) {
-				if (!(mask & 1)) // not this cid
-					continue;
-				if (!(_local_cargo_id_landscape[cid] & (1 << _opt.landscape))) // not in this landscape
-					continue;
-
-				show_cargo(_local_cargo_id_ctype[cid]);
-			}
-
-		} else { // generic refit list
-			b = _rail_vehicle_refit_types[_opt.landscape];
-			do {
-				show_cargo(*b);
-			} while (*++b != 255);
-		}
-
-#undef show_cargo
-
-		WP(w,refit_d).cargo = cargo;
-
-		if (cargo != -1) {
-			int32 cost = DoCommandByTile(v->tile, v->index, cargo, 0, CMD_REFIT_RAIL_VEHICLE);
-			if (cost != CMD_ERROR) {
+		if (WP(w,refit_d).cargo != CT_INVALID) {
+			int32 cost = DoCommandByTile(v->tile, v->index, WP(w,refit_d).cargo, DC_QUERY_COST, CMD_REFIT_RAIL_VEHICLE);
+			if (!CmdFailed(cost)) {
 				SetDParam(2, cost);
-				SetDParam(0, _cargoc.names_long_p[cargo]);
+				SetDParam(0, _cargoc.names_long_p[WP(w,refit_d).cargo]);
 				SetDParam(1, _returned_refit_amount);
 				DrawString(1, 137, STR_9840_NEW_CAPACITY_COST_OF_REFIT, 0);
 			}
 		}
-		break;
-	}
+	}	break;
 
 	case WE_CLICK:
 		switch(e->click.widget) {
@@ -748,8 +698,8 @@ static void RailVehicleRefitWndProc(Window *w, WindowEvent *e)
 			}
 		} break;
 		case 4: /* refit button */
-			if (WP(w,refit_d).cargo != 0xFF) {
-				Vehicle *v = GetVehicle(w->window_number);
+			if (WP(w,refit_d).cargo != CT_INVALID) {
+				const Vehicle *v = GetVehicle(w->window_number);
 				if (DoCommandP(v->tile, v->index, WP(w,refit_d).cargo, NULL, CMD_REFIT_RAIL_VEHICLE | CMD_MSG(STR_RAIL_CAN_T_REFIT_VEHICLE)))
 					DeleteWindow(w);
 			}
@@ -809,9 +759,9 @@ static Widget _train_view_widgets[] = {
 
 static void TrainViewWndProc(Window *w, WindowEvent *e)
 {
-	switch(e->event) {
+	switch (e->event) {
 	case WE_PAINT: {
-		Vehicle *v, *u;
+		const Vehicle *v, *u;
 		StringID str;
 
 		v = GetVehicle(w->window_number);
@@ -820,22 +770,16 @@ static void TrainViewWndProc(Window *w, WindowEvent *e)
 
 		SETBIT(w->disabled_state, 12);
 
-		/* See if any carriage can be refitted */
+		/* See if any vehicle can be refitted */
 		for ( u = v; u != NULL; u = u->next) {
-			if (_engine_refit_masks[u->engine_type] != 0) {
+			if (_engine_refit_masks[u->engine_type] != 0 ||
+						 (!(RailVehInfo(v->engine_type)->flags & RVI_WAGON) && v->cargo_cap != 0)) {
 				CLRBIT(w->disabled_state, 12);
 				/* We have a refittable carriage, bail out */
 				break;
 			}
 		}
 
-		/* Above code doesn't seem to handle non-newgrf engines, do it separately
-		TODO: handle engines which are NOT the head of the train, but don't break wagons */
-		if (v->cargo_cap != 0) {
-			/* we can refit this engine */
-			CLRBIT(w->disabled_state, 12);
-		}
-
 		/* draw widgets & caption */
 		SetDParam(0, v->string_id);
 		SetDParam(1, v->unitnumber);
diff --git a/ttd.h b/ttd.h
index 3c9e4ae2b5..0181987793 100644
--- a/ttd.h
+++ b/ttd.h
@@ -67,6 +67,7 @@ typedef struct DrawPixelInfo DrawPixelInfo;
 typedef uint16 VehicleID;
 typedef byte PlayerID;
 typedef byte OrderID;
+typedef byte CargoID;
 typedef uint16 StringID;
 typedef uint16 SpriteID;
 typedef uint32 PalSpriteID;
diff --git a/vehicle.c b/vehicle.c
index 025bb0679f..a705ed93bb 100644
--- a/vehicle.c
+++ b/vehicle.c
@@ -501,6 +501,28 @@ bool CanFillVehicle(Vehicle *v)
 	return false;
 }
 
+/** Check if a given vehicle (type) can be refitted to a given cargo
+ * @param *v vehicle to check
+ * @param cid_to check refit to this cargo-type
+ * @return true if it is possible, false otherwise
+ */
+bool CanRefitTo(const Vehicle *v, CargoID cid_to)
+{
+	CargoID cid = _global_cargo_id[_opt_ptr->landscape][cid_to];
+
+	if (cid == GC_INVALID) return false;
+
+	if (_engine_refit_masks[v->engine_type]) {
+		if (!HASBIT(_engine_refit_masks[v->engine_type], cid)) return false;
+	} else {
+		/* If we are talking about normal vehicles (no newgrf), you can only refit engines */
+		if (v->type == VEH_Train && (RailVehInfo(v->engine_type)->flags & RVI_WAGON)) return false;
+		if (!HASBIT(_default_refitmasks[v->type - VEH_Train], cid)) return false;
+	}
+
+	return true;
+}
+
 static void DoDrawVehicle(Vehicle *v)
 {
 	uint32 image = v->cur_image;
diff --git a/vehicle.h b/vehicle.h
index a86a1ce378..f0699b5a6e 100644
--- a/vehicle.h
+++ b/vehicle.h
@@ -262,6 +262,7 @@ Vehicle *FindVehicleOnTileZ(TileIndex tile, byte z);
 void InitializeTrains(void);
 
 bool CanFillVehicle(Vehicle *v);
+bool CanRefitTo(const Vehicle *v, CargoID cid_to);
 
 void ViewportAddVehicles(DrawPixelInfo *dpi);
 
diff --git a/vehicle_gui.c b/vehicle_gui.c
index 5832498e88..c83f287ec0 100644
--- a/vehicle_gui.c
+++ b/vehicle_gui.c
@@ -165,6 +165,42 @@ void DrawVehicleProfitButton(Vehicle *v, int x, int y)
 	DrawSprite(SPR_BLOT | ormod, x, y);
 }
 
+/** Draw the list of available refit options.
+ * Draw the list and highlight the selected refit option (if any)
+ * @param *v vehicle(type) to get the refit-options of
+ * @param sel selected refit cargo-type in the window
+ * @return the cargo type that is hightlighted, CT_INVALID if none
+ */
+CargoID DrawVehicleRefitWindow(const Vehicle *v, int sel)
+{
+	uint32 cmask;
+	CargoID cid, cargo = CT_INVALID;
+	int y = 25;
+#define show_cargo(ctype) { \
+		byte colour = 16; \
+		if (sel == 0) { \
+			cargo = ctype; \
+			colour = 12; \
+} \
+		sel--; \
+		DrawString(6, y, _cargoc.names_s[ctype], colour); \
+		y += 10; \
+}
+
+		/* Check if engine has custom refit or normal ones, and get its bitmasked value.
+		 * Now just and it with the bitmasked available cargo on the current landscape, and
+		* where the bits are set: those are available */
+		cmask = (_engine_refit_masks[v->engine_type] != 0) ? _engine_refit_masks[v->engine_type] : _default_refitmasks[v->type - VEH_Train];
+		cmask &= _landscape_global_cargo_mask[_opt_ptr->landscape];
+
+		/* Check which cargo has been selected from the refit window and draw list */
+		for (cid = 0; cmask != 0; cmask >>= 1, cid++) {
+			if (HASBIT(cmask, 0)) // vehicle is refittable to this cargo
+				show_cargo(_local_cargo_id_ctype[cid]);
+		}
+		return cargo;
+}
+
 /************ Sorter functions *****************/
 int CDECL GeneralOwnerSorter(const void *a, const void *b)
 {
diff --git a/vehicle_gui.h b/vehicle_gui.h
index 1af4e0abae..a4e010c696 100644
--- a/vehicle_gui.h
+++ b/vehicle_gui.h
@@ -6,6 +6,7 @@
 struct vehiclelist_d;
 
 void DrawVehicleProfitButton(Vehicle *v, int x, int y);
+CargoID DrawVehicleRefitWindow(const Vehicle *v, int sel);
 void InitializeVehiclesGuiList(void);
 
 /* sorter stuff */