Energy consumption in Iran is a subject of debate. Some may think that oil is cheap in Iran and thus no need for this kind of research. This simple minding is erroneous first because Iran subsidizes billion dollars each year for the imported diesel fuel specially for agricultural use and second because energy studies reveal the degree of professionally using the technology. We can easily find the shortcomings in our mechanization problems. With the upcoming WTO, you have to produce as cheaply as possible to be able to sustain your agriculture. This is not possible without knowing the ways and means of reducing energy consumption. Having the above subjects in mind, this paper is the first of its kind in Iran to be published and hoping not the last. Data was gathered from 150 farmers in an agricultural area near the capital, Tehran. The area although may not be a representative of the arable lands in the country but serves as a good example for the problems that we may face in the future research works . To compare the gathered data on fuel consumption through questioners, the energy coefficients had to be calculated. Two methods of calculation is described. The experimental data then compared with the calculation results and literature references. Statistical analysis was run on five different farm sizes and for 3 major tillage implements that is moldboard plow, disk and land plane. The effect of farm size on tillage energy as well as the experimental and calculated energy coefficient for the tillage implements was compared. High fuel consumption (direct energy) was realized.