I recently had a problem with oil and gas ratios mixing. I wanted a gas oil mixture of 30:1. I had a 7oz bottle of Lawn Boy 2 stroke oil and since there was no scale on the side of the bottle I used a small electronic food weight scale to measure out 4.26 oz. After obtaining the weight of 4.26 oz I added it to one US gallon of gas. I then used it to start my aircraft engine, a DLE 35. Someone told me this was the wrong way to measure out the proper amount of oil. He said measuring the oil in a calibrated measuring cup is different than weighing it. Was I wrong? It seemed to run the engine just fine.