Empty (Near 0%)
1/8 Tank
1/4 Tank
1/2 Tank
3/4 Tank
Full (Near 100%)
How much gas will be left when you drop it off?
Quote from rental counter.
Average price at local pumps.
Usually significantly higher than market rate.
Cost Comparison
Option 1: Prepay (Fuel Service Option)You pay for a full tank upfront. No refund for unused gas.
$0.00
Option 2: Refuel Yourself (DIY)You fill the tank to full at a local station before returning.
$0.00
Option 3: Pay Upon ReturnEnterprise refills the tank at their premium rate.
$0.00
Understanding Enterprise Fuel Rates and Options
When renting a vehicle from Enterprise or other major rental agencies, one of the first decisions you face at the counter is how to handle fuel. This decision can significantly impact the total cost of your rental. Our Enterprise Fuel Rate Calculator helps you compare the three main options to ensure you aren't overpaying for gasoline.
The Three Fuel Options Explained
Rental agreements typically offer three distinct ways to pay for fuel:
Prepay (Fuel Service Option): You purchase a full tank of gas at the time of rental. The price per gallon is often competitive with or slightly lower than local stations. However, the catch is that you are charged for the entire tank, regardless of how much fuel is left when you return the car. There are no refunds for unused fuel.
Refuel Yourself (Market Rate): You pick up the car full and agree to return it full. You pay the local market rate at a gas station near the drop-off location. You only pay for the fuel you actually used.
Pay Upon Return (Post-pay): You return the car with less than a full tank, and the rental agency refills it for you. This is the most expensive option, often charging 2x to 3x the local price per gallon as a convenience fee.
How to Use This Calculator
To determine the most cost-effective method for your specific trip, enter the following details:
Tank Capacity: The size of the fuel tank in gallons. You can find this in the vehicle manual or often on a sticker inside the fuel door.
Expected Fuel Level on Return: Estimate how much gas will be left in the tank when you arrive at the return center if you do not refuel.
Rates: Input the Prepay rate offered at the counter, the average price at local gas stations, and the "We Refuel" penalty rate (often listed on your rental agreement).
When is Prepaying Worth It?
The "Prepay" option is generally a psychological trap. It only makes financial sense if you plan to return the car with the tank nearly empty (less than 10-15% fuel remaining). If you return the car with half a tank, you have essentially paid double per gallon for the fuel you actually consumed.
Tips for Saving on Rental Fuel
The 5-Mile Rule: Most agencies require a receipt from a gas station within 5-10 miles of the return location if you choose to refuel yourself.
Check the Gauge: Take a photo of the fuel gauge and mileage before you drive off the lot and when you return.
Don't Overfill: If you are refueling yourself, stop when the nozzle clicks. Rental agencies only check that the gauge reads "Full".
function calculateFuelCost() {
// 1. Get input values
var tankSize = parseFloat(document.getElementById('tankSize').value);
var returnLevel = parseFloat(document.getElementById('returnLevel').value);
var prepayRate = parseFloat(document.getElementById('prepayRate').value);
var pumpPrice = parseFloat(document.getElementById('pumpPrice').value);
var postpayRate = parseFloat(document.getElementById('postpayRate').value);
// 2. Validate inputs
if (isNaN(tankSize) || tankSize <= 0) {
alert("Please enter a valid tank size.");
return;
}
if (isNaN(prepayRate) || prepayRate <= 0) {
alert("Please enter the Prepay Rate offered at the counter.");
return;
}
if (isNaN(pumpPrice) || pumpPrice <= 0) {
alert("Please enter the local gas station price.");
return;
}
if (isNaN(postpayRate) || postpayRate <= 0) {
// If user leaves blank, assume a high default (e.g. $9.99) or alert.
// Let's alert to ensure accuracy.
alert("Please enter the 'We Refuel' / Pay on Return rate.");
return;
}
// 3. Calculation Logic
// Gallons needed to fill the tank to 100%
// (1 – returnLevel) represents the empty portion.
// Example: Returns at 0.25 (1/4), means 0.75 (3/4) is empty.
var gallonsNeeded = tankSize * (1 – returnLevel);
// SCENARIO 1: PREPAY (Fuel Service Option)
// You pay for the FULL tank size regardless of return level.
var costPrepay = tankSize * prepayRate;
// SCENARIO 2: DIY REFUEL
// You only buy the gallons needed to fill it back up at market price.
// If return level is roughly 1 (Full), cost is 0.
var costDIY = gallonsNeeded * pumpPrice;
// SCENARIO 3: POST-PAY (We Refuel)
// Agency fills the missing gallons at the penalty rate.
var costPostpay = gallonsNeeded * postpayRate;
// 4. Display Results
document.getElementById('results').style.display = 'block';
document.getElementById('resPrepay').innerHTML = '$' + costPrepay.toFixed(2);
document.getElementById('resDIY').innerHTML = '$' + costDIY.toFixed(2);
document.getElementById('resPostpay').innerHTML = '$' + costPostpay.toFixed(2);
// 5. Comparison Logic and Styling
var options = [
{ id: 'optionPrepay', cost: costPrepay, name: 'Prepay' },
{ id: 'optionDIY', cost: costDIY, name: 'Refuel Yourself' },
{ id: 'optionPostpay', cost: costPostpay, name: 'Pay Upon Return' }
];
// Reset classes
var cards = document.getElementsByClassName('scenario-card');
for (var i = 0; i < cards.length; i++) {
cards[i].classList.remove('best-option');
cards[i].classList.remove('worst-option');
}
// Find min and max
var minCost = Math.min(costPrepay, costDIY, costPostpay);
var maxCost = Math.max(costPrepay, costDIY, costPostpay);
var bestOptionName = "";
var savings = 0;
// Apply classes
for (var j = 0; j < options.length; j++) {
var el = document.getElementById(options[j].id);
if (options[j].cost === minCost) {
el.classList.add('best-option');
bestOptionName = options[j].name;
}
if (options[j].cost === maxCost) {
el.classList.add('worst-option');
}
}
// Calculate savings against the next best alternative (or worst case)
// If Prepay is best, compare to DIY. If DIY is best, compare to Prepay.
var comparisonCost = (bestOptionName === 'Prepay') ? costDIY : costPrepay;
if (bestOptionName === 'Refuel Yourself' && costPostpay < costPrepay) {
comparisonCost = costPostpay; // rare edge case
}
var diff = comparisonCost – minCost;
var recText = "Recommendation: Choose " + bestOptionName + ".";
if (diff > 0) {
recText += "You will save approximately $" + diff.toFixed(2) + " compared to the next option.";
} else {
recText += "The costs are identical.";
}
// Contextual advice
if (bestOptionName === 'Prepay') {
recText += "Note: This only works if you truly return the car this empty!";
}
document.getElementById('recommendation').innerHTML = recText;
}