I use producer's fertilizer with a standard scott's broadcast spreader set at 5. It depends a bit on how fast you walk. Sometimes I go to 5.5 or 6.
I have found that Producer's makes an excellent fertilizer and as mentioned much cheaper than scott's/pennington's etc. I only put down the summer ('maintenance', 50 lb $17 this summer) in april and 'winterizer' in late oct, I skip the 'foundation' (early spring) and still have the greenest weed-free yard on the block.
Scott's blends are more homogeneous than producer's and the scott's particles are much smaller as well. These are the only advantages to scott's but still not worth the large price difference in my opinion.
(Because the producer's particles are larger, you need to use a higher setting than is needed to spread the same amount (lbs) of a scott's product. Most scott's product's have a suggested setting ~3, so if you are used to scott's products don't be afraid of the higher setting with producer's products).