Quick Summary:
- Open the fuel flap and read any label stating fuel type.
- Check the key tag for fuel notes like diesel, flex-fuel, or EV.
- Confirm fuel policy and fuel type on the rental agreement before exiting.
- Match octane guidance to the pump, then reset trip to track fuel.
Misfuelling is one of the easiest ways to turn a smooth Texas trip into an expensive delay. In the US, most cars take regular unleaded petrol, but not all. You might be handed a diesel model, a flex-fuel vehicle that accepts E85, a hybrid that still needs petrol, or an EV that needs charging rather than filling. The safest approach is a quick, repeatable check you can do at the bay or exit lane before you drive off.
This guide shows exactly where to confirm fuel type and any required petrol grade: on the car itself, on the key tag, and on your rental agreement. The goal is to leave the lot certain about what goes in the tank, and what does not.
Step 1: Start with the car, not the pump
Before you even think about petrol grade, confirm the fuel type. The most reliable information is usually on the vehicle, because that is tied to the specific car you are driving. Do this while you are still parked in the pickup area, when swapping vehicles is easiest.
Check the fuel door and filler area. Walk to the side of the car where the fuel flap is located and open it. Many vehicles have a sticker or moulded text inside the fuel door or around the filler neck that indicates one of the following:
Unleaded petrol only, diesel fuel only, flex-fuel or E85, or in rare cases premium unleaded recommended or required.
Even when there is no explicit sticker, the filler neck design can still help. Most US petrol nozzles are slightly larger than unleaded nozzles in some other countries, while diesel nozzles are typically larger and may not fit into a petrol filler neck. Do not rely on size alone, because some modern cars have capless systems, but it can be a clue.
Look for external badges. Manufacturers often label diesel models with a “DIESEL” badge, and some flex-fuel cars have “FlexFuel” markings near the rear. Hybrids often have “Hybrid” or similar badging, but remember that hybrids still use petrol, unless it is a plug-in hybrid and you are charging as well.
Check the instrument cluster. When you switch the ignition on, some cars display a diesel icon, “AdBlue” or “DEF” related messages, or EV range and charging prompts. EVs will not have a fuel gauge in the usual sense, they show battery percentage and range.
Step 2: Confirm the required petrol grade, if petrol is correct
Once you have confirmed the car is petrol, the next question is octane. In Texas you will commonly see three petrol grades at pumps: 87, 89, and 91 or 93. The number is the AKI rating used in the US, which differs from the UK RON number. The important point is not conversion, it is matching what the car asks for to what the pump offers.
Check for “Regular Unleaded” versus “Premium Required”. Many mainstream models run on regular unleaded (often 87). Some performance or turbocharged cars specify premium (often 91 or 93). The fuel door sticker or the owner information sticker near the filler usually states “Premium Unleaded Fuel Only” if it is required. If it says “Recommended”, regular will often work but may reduce performance. Follow the wording on the car and the agreement.
Do not confuse grade with ethanol blends. Most US pumps dispense E10 as standard unleaded. That is normal for many vehicles. E15 is less common and E85 is specific to flex-fuel vehicles. If your car is not labelled flex-fuel, avoid E85.
Step 3: Read the key tag, it is there for a reason
The key tag is often the fastest confirmation point because staff use it to reduce mix-ups. It may include abbreviations like “DIESEL”, “FFV”, “E85”, “EV”, or occasionally a note such as “PREM”. If the key tag contradicts the car’s fuel door label, treat that as a red flag and stop to clarify before leaving.
Key tags can also include practical reminders about the fuel policy, for example whether you are expected to return the car full or return it at the same level. That does not change the fuel type, but it matters for how you plan your final fill in Texas.
Step 4: Check the rental agreement for fuel type and fuel policy
Your agreement is the third place to verify details, and it is especially useful if labels are missing or unclear. Look for a section covering vehicle description and fuel. It might list fuel type explicitly, and it will usually confirm the fuel policy, such as “return full” or “prepaid fuel”.
Why this matters: if the agreement says the vehicle is diesel and you fill it with petrol, the vehicle can suffer significant damage. Likewise, if it is petrol and you put diesel in, it may not start or may stall quickly. The agreement is also important for disputes, because it is your record of what you were provided.
If you arranged your car hire through Hola Car Rentals for a Texas airport pickup, keep your confirmation emails and any vehicle class notes to hand, and compare them with what you receive at the counter. For airport contexts you can also review location-specific details on pages such as Houston IAH car rental or San Antonio SAT car rental while you plan your arrival.
A quick “before you exit the lot” checklist
Use this simple sequence every time, especially when you are tired after a flight.
1) Open the fuel door. Look for a sticker or imprint that states diesel, unleaded, flex-fuel, or premium required.
2) Match it to the dashboard. Confirm the car behaves like the stated type, for example EV prompts for an EV, or standard fuel gauge for petrol and diesel.
3) Read the key tag. Look for fuel abbreviations and ensure they match what you just saw on the car.
4) Confirm on the agreement. Verify fuel type and fuel policy. If anything conflicts, resolve it before leaving.
5) Set a tracking habit. Reset the trip meter or note mileage and fuel gauge. This helps you plan refuelling and return conditions.
Common fuel types you might see in Texas car hire fleets
Unleaded petrol (most common). Typically “Regular Unleaded” is fine unless the car specifies premium. Texas pumps often label grades clearly as 87, 89, 91, or 93.
Diesel. Less common in standard fleets, more common in some SUVs or pickups. Diesel pumps are usually labelled “Diesel” and often have green handles, but do not rely on handle colour.
Flex-fuel (E85 capable). A flex-fuel vehicle can use petrol or E85, but it does not require E85. Unless you understand availability and consumption differences, standard unleaded is usually simpler. Confirm the car is explicitly flex-fuel before using E85.
Hybrid and plug-in hybrid. Hybrids still need petrol. Plug-in hybrids can charge as well, but you still need to use the correct petrol grade if the engine runs.
EV. No petrol or diesel. Confirm charging connectors and whether a charging card or app is required. For EVs, the “fuel type” question becomes a charging compatibility question.
What to do if labels are missing or information conflicts
Occasionally fuel door stickers are worn, or the key tag is wrong after a fast turnaround. If you cannot clearly verify fuel type in under two minutes, treat that as a sign to pause.
Ask for a staff confirmation at the bay or exit. It is easier to swap cars or fix documentation before you leave. If you are at a busy airport location, have the vehicle plate or unit number ready to speed up the check.
Take a quick photo for your records. Photograph the fuel door area and the agreement line showing fuel policy. This is useful if you later discover a mismatch.
Do not “test” with a small amount of fuel. Even a small amount of the wrong fuel can cause problems, and it can still be treated as misfuelling.
How this affects refuelling for return
Knowing the correct fuel type helps you avoid misfuelling, but it also helps you avoid unnecessary charges. If your policy is to return full, locate a station close to the return point and refuel shortly before drop-off. If your policy is to return at the same level, confirm the gauge position at pickup and aim to match it.
Airport areas can be congested, so build in time to refuel and still reach the return lanes. If you are travelling with family or extra luggage, selecting the right vehicle class can also reduce stress. For example, if you are collecting near Dallas and need more space, you might look at information on minivan rental at Fort Worth DFW. If you are flying into Austin, the Enterprise car hire at Austin AUS page can help you understand the pickup context before you arrive.
Texas pump reading tips for UK visitors
US fuel pumps usually show the grade number prominently and the price per gallon. You may also see a label such as “May contain up to 10% ethanol”. That is typical and usually fine for unleaded petrol cars unless the car specifically states otherwise.
Remember that “gas” in the US means petrol. “Diesel” is always labelled as diesel. If your car requires premium, select the 91 or 93 option if available. If your car is regular, 87 is usually the correct choice unless the fuel door specifies higher.
If you are unsure at the pump, stop and re-check the fuel door label rather than guessing. That ten-second check can prevent a much larger problem.
FAQ
Where is the quickest place to confirm fuel type before leaving? Open the fuel flap and read the label inside the door or near the filler neck. Then cross-check the key tag and agreement.
If the pump has 87, 89, and 93, which one should I choose? Choose the grade stated on the fuel door label. Most cars take regular (87), but if it says premium required, use 91 or 93.
Can I use E85 if it is cheaper in Texas? Only if the car is clearly labelled flex-fuel or FFV. If it is not, do not use E85, as it may cause running issues or damage.
What should I do if the key tag says diesel but the fuel door does not? Do not drive off. Ask staff to confirm the vehicle fuel type, and have the agreement corrected or the vehicle swapped.
How can I avoid refuelling charges at return? Follow the agreement’s fuel policy, note the starting gauge level, and refuel near the return location with the correct fuel type and grade.
