diff --git a/src/api/map.js b/src/api/map.js
index 173c1a703b..baffd2f4e6 100644
--- a/src/api/map.js
+++ b/src/api/map.js
@@ -31,6 +31,8 @@ ol.map = function(opt_arg){
     var userProjection;
     /** @type {ol.Bounds|undefined} */
     var maxExtent;
+    /** @type {ol.Bounds|undefined} */
+    var maxRes;
     /** @type {Array.<number>|undefined} */
     var resolutions;
     /** @type {Array|undefined} */
@@ -47,6 +49,7 @@ ol.map = function(opt_arg){
             projection = opt_arg['projection'];
             userProjection = opt_arg['userProjection'];
             maxExtent = opt_arg['maxExtent'];
+            maxRes = opt_arg['maxRes'];
             resolutions = opt_arg['resolutions'];
             layers = opt_arg['layers'];
         }
@@ -74,6 +77,9 @@ ol.map = function(opt_arg){
     if (goog.isDef(maxExtent)) {
         map.setMaxExtent(ol.bounds(maxExtent));
     }
+    if (goog.isDef(maxRes)) {
+        map.setMaxRes(maxRes);
+    }
     if (goog.isDef(resolutions)) {
         map.setResolutions(resolutions);
     }
@@ -187,3 +193,24 @@ ol.Map.prototype.maxExtent = function(opt_arg) {
         return this.getMaxExtent();
     }
 };
+
+/**
+ * @param {number=} opt_arg  
+ * @returns {ol.Map|number|undefined} Map maximum resolution
+ */
+ol.Map.prototype.maxRes = function(opt_arg) {
+    if (arguments.length == 1 && goog.isDef(opt_arg)) {
+        this.setMaxRes(opt_arg);
+        return this;
+    } else {
+        return this.getMaxRes();
+    }
+};
+
+/**
+ * @param {number} arg  
+ * @returns {number} resolution for a given zoom level
+ */
+ol.Map.prototype.getResForZoom = function(arg) {
+    return this.getResolutionForZoom(arg);
+};
diff --git a/src/api/projection.js b/src/api/projection.js
index 27bf1254e4..d8ff8c9821 100644
--- a/src/api/projection.js
+++ b/src/api/projection.js
@@ -21,6 +21,9 @@ ol.projection = function(opt_arg){
     /** @type {undefined|number} */
     var units;
 
+    /** @type {undefined|Array|ol.UnreferencedBounds} */
+    var extent;
+
     if (arguments.length == 1 && goog.isDefAndNotNull(opt_arg)) {
         if (opt_arg instanceof ol.Projection) {
             return opt_arg;
@@ -35,13 +38,21 @@ ol.projection = function(opt_arg){
                 throw new Error('Projection requires a string code.');
             }
             units = opt_arg['units'];
+            extent = opt_arg['maxExtent'];
         }
         else {
             throw new Error('ol.projection');
         }
     }
     var proj = new ol.Projection(code);
-    proj.setUnits(units);
+    if (goog.isDef(units)) {
+        proj.setUnits(units);
+    }
+    if (goog.isDef(extent)) {
+        proj.setExtent(
+            new ol.UnreferencedBounds(extent[0],extent[1],extent[2],extent[3])
+        );
+    }
     return proj;
 };
 
diff --git a/src/ol/Map.js b/src/ol/Map.js
index 1a2462aaf2..2529f14953 100644
--- a/src/ol/Map.js
+++ b/src/ol/Map.js
@@ -52,6 +52,18 @@ ol.Map = function() {
      */
     this.layers_ = null;
 
+    /**
+     * @private
+     * @type {ol.UnreferencedBounds|undefined}
+     */
+    this.maxExtent_ = null;
+
+    /**
+     * @private
+     * @type {number|undefined}
+     */
+    this.maxRes_ = null;
+
 };
 
 /**
@@ -64,7 +76,16 @@ ol.Map.prototype.DEFAULT_PROJECTION = "EPSG:3857";
   @type {string}
 */
 ol.Map.prototype.DEFAULT_USER_PROJECTION = "EPSG:4326";
-
+/**
+  @const
+  @type {number}
+*/
+ol.Map.ZOOM_FACTOR = 2;
+/**
+  @const
+  @type {number}
+*/
+ol.Map.DEFAULT_TILE_SIZE = 256;
 
 /**
  * @return {ol.Loc} Location.
@@ -145,6 +166,39 @@ ol.Map.prototype.getMaxExtent = function() {
 };
 
 
+/**
+ * @return {number} the max resolution for the map
+ */
+ol.Map.prototype.getMaxRes = function() {
+    if (goog.isDefAndNotNull(this.maxRes_)) {
+        return this.maxRes_;
+    } else {
+        var extent = this.getMaxExtent();
+        if (goog.isDefAndNotNull(extent)) {
+            var dim = Math.max(
+                (extent.getMaxX()-extent.getMinX()),
+                (extent.getMaxY()-extent.getMinY())
+             );
+            return dim/ol.Map.DEFAULT_TILE_SIZE;
+        }
+    }
+};
+
+
+/**
+ * @param {number} zoom the zoom level being requested
+ * @return {number} the resolution for the map at the given zoom level
+ */
+ol.Map.prototype.getResolutionForZoom = function(zoom) {
+    if (goog.isDefAndNotNull(this.resolutions_)) {
+        return this.resolutions_[zoom];
+    } else {
+        var maxRes = this.getMaxRes();
+        return maxRes/Math.pow(ol.Map.ZOOM_FACTOR, zoom);
+    }
+};
+
+
 /**
  * @param {ol.Loc} center Center.
  */
@@ -205,6 +259,13 @@ ol.Map.prototype.setMaxExtent = function(extent) {
     this.maxExtent_ = extent;
 };
 
+/**
+ * @param {number} res the max resolution for the map
+ */
+ol.Map.prototype.setMaxRes = function(res) {
+    this.maxRes_ = res;
+};
+
 /**
 */
 ol.Map.prototype.destroy = function() {
diff --git a/src/ol/Projection.js b/src/ol/Projection.js
index 90937f0d5c..63da6b4a9f 100644
--- a/src/ol/Projection.js
+++ b/src/ol/Projection.js
@@ -21,15 +21,15 @@ ol.Projection = function(code) {
     
     /**
      * @private
-     * @type {!Object|undefined}
+     * @type {Object}
      */
-    this.proj_ = undefined;
+    this.proj_ = null;
 
     /**
      * @private
-     * @type {!ol.UnreferencedBounds|undefined}
+     * @type {ol.UnreferencedBounds}
      */
-    this.extent_ = undefined;
+    this.extent_ = null;
 
 };
 
@@ -65,9 +65,18 @@ ol.Projection.prototype.setUnits = function(units) {
 /**
  * Get the validity extent of the coordinate reference system.
  * 
- * @return {!ol.UnreferencedBounds|undefined} The valididty extent.
+ * @return {ol.UnreferencedBounds} The valididty extent.
  */
 ol.Projection.prototype.getExtent = function() {
+    if (goog.isNull(this.extent_)) {
+        var defs = ol.Projection['defaults'][this.code_];
+        if (goog.isDef(defs)) {
+            var ext = defs['maxExtent'];
+            if (goog.isDef(ext)) {
+                this.setExtent(new ol.UnreferencedBounds(ext[0],ext[1],ext[2],ext[3]));
+            }
+        }
+    }
     return this.extent_;
 };
 
diff --git a/test/spec/api/map.test.js b/test/spec/api/map.test.js
index c7e8ada22a..db43cf884c 100644
--- a/test/spec/api/map.test.js
+++ b/test/spec/api/map.test.js
@@ -164,7 +164,7 @@ describe("ol.map", function() {
         
         map.destroy();
 
-        expect(goog.isDef(map.layers)).toBe(false);
+        expect(goog.isDef(map.getLayers())).toBe(false);
         
     });
     
@@ -199,11 +199,11 @@ describe("ol.map", function() {
         var map = ol.map();
         
         var extent = map.maxExtent();
-        expect(extent).toBeA(ol.Bounds);
-        expect(extent.minX()).toBe(-20037508.34);
-        expect(extent.maxX()).toBe(-20037508.34);
-        expect(extent.minY()).toBe(20037508.34);
-        expect(extent.maxY()).toBe(20037508.34);
+        expect(extent).toBeA(ol.UnreferencedBounds);
+        expect(extent.getMinX()).toBe(-20037508.34);
+        expect(extent.getMaxX()).toBe(20037508.34);
+        expect(extent.getMinY()).toBe(-20037508.34);
+        expect(extent.getMaxY()).toBe(20037508.34);
         
     });
     
@@ -212,11 +212,11 @@ describe("ol.map", function() {
         map.maxExtent([-5,-4,7,9]);
         
         var extent = map.maxExtent();
-        expect(extent).toBeA(ol.Bounds);
-        expect(extent.minX()).toBe(-5);
-        expect(extent.maxX()).toBe(-4);
-        expect(extent.minY()).toBe(7);
-        expect(extent.maxY()).toBe(9);
+        expect(extent).toBeA(ol.UnreferencedBounds);
+        expect(extent.getMinX()).toBe(-5);
+        expect(extent.getMaxX()).toBe(7);
+        expect(extent.getMinY()).toBe(-4);
+        expect(extent.getMaxY()).toBe(9);
         
     });
     
@@ -225,11 +225,11 @@ describe("ol.map", function() {
         map.projection("CRS:84");
         
         var extent = map.maxExtent();
-        expect(extent).toBeA(ol.Bounds);
-        expect(extent.minX()).toBe(-180);
-        expect(extent.maxX()).toBe(-90);
-        expect(extent.minY()).toBe(180);
-        expect(extent.maxY()).toBe(90);
+        expect(extent).toBeA(ol.UnreferencedBounds);
+        expect(extent.getMinX()).toBe(-180);
+        expect(extent.getMaxX()).toBe(180);
+        expect(extent.getMinY()).toBe(-90);
+        expect(extent.getMaxY()).toBe(90);
         
     });
     
@@ -244,7 +244,7 @@ describe("ol.map", function() {
         var map = ol.map();
         
         var res = map.maxRes();
-        expect(res.toFixed(5)).toBe(1.40625);
+        expect(res.toFixed(5)).toBe("156543.03391");
         
     });
     
@@ -261,22 +261,35 @@ describe("ol.map", function() {
     it("getMaxRes returns correct for custom maxExtent", function() {
         var map = ol.map({
             projection: ol.projection({
+                code: 'foo',
                 maxExtent: [0,0,90,90]
             })
         });
         
         var res = map.maxRes();
-        expect(res.toFixed(7)).toBe(0.3515625);
+        expect(res.toFixed(7)).toBe("0.3515625");
         
     });
     
-    it("getResForZoom returns correct defaults", function() {
+    it("returns correct getResForZoom for default map", function() {
         var map = ol.map();
         
-        res = map.getResForZoom(0);
-        expect(res.toFixed(5)).toBe(1.40625);
+        var res = map.getResForZoom(0);
+        expect(res.toFixed(5)).toBe("156543.03391");
         res = map.getResForZoom(5);
-        expect(res.toFixed(10)).toBe(0.0439453125);
+        expect(res.toFixed(5)).toBe("4891.96981");
+        
+    });
+    
+    it("returns correct getResForZoom when resolution array is set",function() {
+        var map = ol.map({
+            resolutions: [1,4,7,9,12]
+        });
+        
+        var res = map.getResForZoom(0);
+        expect(res).toBe(1);
+        res = map.getResForZoom(3);
+        expect(res).toBe(9);
         
     });