Updated: July 17, 2026
Short answer
A rented exotic car takes premium unleaded gasoline, usually 91 to 93 octane, never diesel and never E85. You return it at the same fuel level you got it. Bring it back lower and a refueling fee applies.
Every car we rent takes premium unleaded gasoline, the highest-octane pump grade, usually 91 to 93 octane in the United States. None of them take diesel. None of them take E85 or any flex-fuel blend. The return rule is just as simple: you bring the car back at the same fuel level you received it. If the tank comes back lower than it left, a refueling fee applies.
Premium unleaded gasoline, 91 to 93 octane, goes in every car in our fleet. In the U.S., pump grades run 87 for regular, 88 to 90 for midgrade, and 91 to 94 octane for premium, per the Department of Energy's FuelEconomy.gov guide. Our cars sit at the top of that scale. You fill them at the same gas stations you use for a normal car. You just press the button for premium instead of regular.
A few things these cars do not take, so there is no confusion at the pump. They are not diesel, so the green diesel handle is never the right one. They do not use E85, the 85 percent ethanol blend sold at some stations, because their engines are not flex-fuel. Putting diesel or a high-ethanol blend in one of these engines can cause real damage, which is why the fuel type is worth knowing before your first fill-up.
Octane is the one number that matters at the pump. Octane is a fuel's resistance to burning early under pressure, and a higher number means more resistance. Regular gas has enough for an ordinary engine. A supercar engine needs more, and the reason is in how it is built.
High-performance engines demand premium because they squeeze the fuel and air far harder than a normal engine, and low-octane fuel cannot handle that pressure. When you compress an air and fuel mix into a smaller space with more force, lower-octane fuel can ignite on its own before the spark plug fires. That early, uncontrolled burn is called knock or detonation. One explainer from SlashGear describes the effect as tiny hammers pounding away at the piston. Over time, knock can crack pistons and wreck an engine. Higher octane resists that early ignition, so the burn happens when it should.
You can see why in the hardware. The 2025 Corvette Z06 runs a 5.5-liter LT6 V8 with a 12.5:1 compression ratio, one of the most aggressive figures in any street car, and it is the most powerful naturally aspirated V8 ever fitted to a production car at 670 horsepower, per The Drive's engine breakdown. Pack that much air and fuel that tightly and only premium keeps the burn under control. The Lamborghini Urus S attacks it from the other direction, with a 4.0-liter twin-turbocharged V8 making 657 horsepower. Turbochargers force extra air into the cylinders, which raises pressure the same way high compression does, so turbo engines also call for premium. The Ferrari 458 Italia takes it high and fast, with a naturally aspirated V8 that spins to a 9,000 rpm redline. The McLaren 600LT and BMW M2 Competition both run twin-turbo engines. Different recipes, same fuel requirement.
This is not a niche demand anymore. The Department of Energy reports that manufacturers have recommended or required premium gasoline for more than half of all light-duty vehicle configurations since model year 2018, as turbocharging and higher compression spread across the market. On an exotic, though, premium is not a suggestion. FuelEconomy.gov's rule is plain: "You should use the octane rating required for your vehicle by the manufacturer." Running below it makes the engine run poorly and, in the wrong conditions, invites knock. So the guidance is short. Fill with premium every time, and never try to save a few dollars with a lower grade.
You return the car at the same fuel level you received it. The car's condition is checked at handoff and again at return. If a car is handed over at three-quarters for any reason, that is the mark you return it at.
The reason we run it this way is fairness in both directions. You only pay for the fuel you actually use, and you are never charged for gas that was already gone when you picked the car up. Knowing the level at handoff is what protects you. Here is the sequence to keep it clean:
That is the whole policy. Fill to the agreed level, keep the receipt, and the fuel side of your return is done.
Returning an exotic under-fueled costs more than the gas you skipped, because a refueling fee applies if the car comes back lower than it left. The exact terms for your rental are confirmed on your agreement, so ask what your car's return terms are before you drive off. Fuel and return terms can change, so confirm your car's current terms rather than relying on an older quote.
The simplest move is to fill it yourself before you return. There is one more reason to use premium at that final fill: putting a lower-octane grade in the tank to save money is exactly what these engines are built to reject, and it is not worth the risk to an engine like the Corvette's hand-built LT6. Fill with premium, fill to the agreed mark, and the fee never enters the picture.
One practical note for planning. Premium is a common grade, so finding it near Scottsdale is not a problem, but not every small or discount station carries 91 or higher. Give yourself a known station and a little buffer time on your way back, rather than hunting for premium with the clock running.
The fuel story is short: premium unleaded, 91 to 93 octane, returned at the level you got it, receipt in hand. Handle that and there is nothing else to think about on the fuel side. If you want the exact return terms for the car you have in mind, or you want us to walk you through the pickup gauge in person, we can lay it all out before you book. Call or text (623) 400-3031, or send a DM to @grantmotorgroup on Instagram, and we will get your dates held and your car ready to roll, delivered anywhere in Scottsdale.
Call or text (623) 400-3031 or send a DM to @grantmotorgroup on Instagram. We deliver anywhere in Scottsdale.
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