-- Filling up your tank in the morning when it's cooler makes no difference in cost savings because the 35,000-gallon underground tanks do not dramatically change temperature in daily cycles.

- Larger fuel retailers turn over supply very rapidly, greatly reducing the fuel's time spent in the underground, insulated tanks.

- Fuel experiences significant expansion and contraction with temperature changes:

- Canada and Hawaii have used automatic temperature adjustment devices at retail fuel pumps for a number of years.