because its a lower gas to oil. think of it this way, if you have 50 cups of water and 1 cup of dye and mix them together, the color of the water will be lighter (in color) than a mixture of 43 cups of water and 1 cup of dye. 43:1 is more contrated. 50:1 has more water than 43:1 but the same amout of dye. get it? now just replace "water" with gas and "dye" with oil. everybody says im wrong but thats the way it really works.