E98 Pump Gas? in General E85 Discussions Posted July 6, 2014 · Report reply I would suggest pumping into a 2 1/2 gal container, then sampling from that. This is particularly important if from a blender or a multi-product dispenser which could hold a quart in the manifold of the pump. Collect this sample towards the end of filling your car. Let E85 sample be at the same temperature as the (preferably distilled) water used in the sample. Play close attention to settle times- don't rush it but do not wait more than 10 minutes either. The sample method I posted was the one recommended by the DOE over the years- less water makes for more variation.