If you are unsure what quantity to order, we recommend that you suit your own budget and match the order quantity with the maximum value that you wish to spend. ValueOils.com will never deliver more than this maximum value and we will never overfill your tank. We will simply reduce the order size and value of your bill pro-rata to the quantity your tank holds - We never make a surcharge on the litre rate if the quantity delivered is less than the quantity ordered.( Unlike our competitors !) The traditional industry standard delivery for a domestic household is 900 litres (approx 200 gallons) - However, many customers order 1,350 litres (approx 300 gallons)- Whilst others on a smaller budget will opt for 450 Litres (approx 100 gallons).- With ValueOils.com, we're delighted to receive your order irrespective of the size - and remember, unlike our competitors, you will always be quoted consistently lower rates per litre whether your order is big or small !. Unlike our competitors, we do not add large surcharges to smaller orders - We sell at lower rates per litre across the range of delivery sizes. What this means is, if you want to fill your tank, just enter a large quantity (or approximately your tank's capacity). The quantities and values ordered and delivered will all be confirmed via e-mail along with your final price (at no extra cost.)