Video: Nearly 2,400 km on one tank. How is that possible?

This was not a normal long-distance drive, nor something every driver should try to copy on the morning commute. It was a hypermiling attempt: an extreme economy-driving exercise in which every detail, from tyre pressures to wind direction, served one goal — burning as little fuel as possible.

The car: an old Passat, the right engine and a lot of preparation

The test car was a 1998 Volkswagen Passat B5, internally known as the 3B, powered by a 1.9-litre TDI engine. More precisely, it used the 110 hp AFN-code diesel, one of the best-known and most durable engines of that generation.

According to the driver, the standard tank holds around 64 litres, plus reserve. For this run, however, the car was filled right to the brim using the tank-venting trick. After the pump first clicked off, the vent button inside the filler neck was pressed down and fuelling continued until the tank was filled to the very top. The fuel cap was then secured with tamper seals to rule out any secret refuelling along the way.

That detail matters. The near-2,400 km result was not achieved with a Passat filled only to the first pump click. The tank’s capacity was used to the absolute maximum, and the final calculated amount of fuel used came to around 72.07 litres. On that basis, average consumption worked out at roughly 3.005 l/100 km.

How the Passat was prepared

The attempt began with preparation. First, everything unnecessary was removed from the car. To save a little weight, surplus items were taken out, and the roof rails and antenna were removed as well. Taken individually, the gains were tiny, but in a test like this, every detail counts.

On the technical side, a faulty coolant thermostat was replaced, along with the air filter, cabin filter and fuel filter. Cruise control was also fitted, because keeping throttle input as steady as possible is one of the most important factors in reducing fuel consumption.

All fluids were changed, and the engine was filled with low-friction 0W-30 oil. Premium diesel was used, with a fuel additive also added to the tank. LED bulbs were fitted to the headlights to reduce electrical load if driving in the dark became necessary. The air-conditioning compressor belt was removed, and parts of the front end were taped over to reduce both drag and the load from auxiliary systems.

The tyres were a separate topic. The Passat was fitted with 175/65 R15 Michelin Energy Saver tyres, inflated to 4.0 bar, with smooth covers added to the wheels. That combination reduces rolling resistance and improves aerodynamics, but a 4.0-bar tyre pressure is not something to copy in normal use unless it falls within the limits set by the vehicle or tyre manufacturer.

Driving strategy: slow, steady and with help from the wind

The route ran from Germany through Denmark into Sweden, then north towards the Arctic Circle. The start was made very early in the morning to avoid traffic around Hamburg and queues at the Elbe Tunnel. That was one of the key practical decisions, because standing still, accelerating and slow urban traffic can destroy the result in a test like this.

On the motorway, the main strategy was to drive behind lorries. The driver looked for slower lorries and lorry convoys, because the slipstream behind them reduces aerodynamic drag. He noted that a convoy of five to seven lorries could be more effective than a single lorry, especially when the vehicles were travelling fairly close together.

By normal traffic standards, the speeds were very low. The ideal pace was around 80–85 km/h, but in Sweden he spent long stretches at 70 km/h, because at that speed the car used less fuel than it did following faster lorries. If a lorry was travelling at 95–100 km/h, he stopped following it, because the extra consumption from the higher speed cancelled out the benefit of slipstreaming.

The weather also helped. The driver monitored wind direction and was able to cover part of the route with a tailwind. That does not create a miracle on its own, but over a distance of more than 2,000 km, small gains like that can ultimately mean dozens of extra kilometres.

The extreme tricks you should not copy

The most radical economy measures in the test involved coasting. On descents, the driver depressed the clutch or shifted into neutral, because he believed it allowed the car to roll for longer than it would under engine braking. Under engine braking, fuel consumption may briefly drop to zero, but the car slows down more quickly. Coasting in neutral uses a little fuel at idle, but in some situations it can preserve more momentum.

Even more extreme was the technique used towards the end: switching the engine off on descents and letting the car roll. That may save the last few millilitres of fuel, but in normal traffic it is a bad and dangerous idea. When the engine is switched off, power steering and brake assistance may no longer work normally, and there is also a risk of the steering lock engaging if the ignition key is handled incorrectly. This is not a technique that should be used on public roads.

Driving in a lorry’s slipstream also needs to be clearly separated from safe following distance in everyday use. The physics are simple: less aerodynamic drag means lower consumption. The real-world risk is just as clear: following too closely behind a lorry reduces visibility and reaction time, and can have serious consequences. The saving is not worth the crash risk.

The result: the Arctic Circle was reached, and the tank ran dry later

The attempt achieved its goal. The Passat reached the Arctic Circle in Sweden on a single tank. After reaching the target, the car continued towards the nearest filling station until the engine began to run unevenly because the tank was empty. The run ended at 2,398 km.

Five litres of diesel were then added from a jerrycan. The next filling station did not have diesel, so the car had to continue to another working station. The driver calculated that about one litre from the jerrycan had been used before the final fill-up. In the final calculation, the fuel added to the tank and the remaining fuel in the jerrycan were taken into account, giving a total of around 72.07 litres. Divided by 2,398 kilometres, that gives roughly 3.0 l/100 km.

It is an impressive figure, but it needs to be interpreted correctly. It does not show average consumption in normal use. It shows what can be achieved with an old, aerodynamic diesel saloon when the driver sacrifices speed, comfort, time and much of what normally makes sense in everyday traffic.

What can an ordinary driver actually learn from it?

The most sensible fuel-saving tips are not extreme. They are boring, but they work.

First, keep the car in good mechanical condition. A faulty thermostat, clogged filters, the wrong oil, sticking brakes or incorrect wheel alignment can raise fuel consumption more than most drivers realise. If the engine does not reach its proper operating temperature, or the car is fighting excess rolling resistance, no economy-driving trick will rescue the result.

Second, remove unnecessary weight and external drag. Roof racks, roof boxes and unused clutter carried around in the car all increase consumption. The difference may not be obvious in town, but on the motorway, aerodynamic drag is the main enemy.

Third, tyres matter. Correct pressure, adequate tread and low-rolling-resistance tyres can all help reduce fuel use. But tyre pressure should not be blindly raised beyond the recommended range. Too much pressure can reduce grip, cause uneven tyre wear and make the car less predictable. The sensible limit is the manufacturer’s recommendation, or the upper end of the permitted range — not the number from a YouTube record attempt.

Fourth, speed matters more than most drivers like to admit. Driving at 90 km/h instead of 110 km/h can noticeably reduce fuel consumption on the open road. Driving more slowly does not have to mean holding up traffic, but a steady pace, gentler acceleration and better anticipation deliver bigger real-world savings than any fuel additive.

Fifth, avoid unnecessary braking and acceleration. An economical driver looks far ahead, lifts off early and uses the car’s momentum. That does not mean coasting in neutral or rolling with the engine switched off. It means driving smoothly: fewer abrupt inputs, fewer panic stops and fewer pointless overtakes.

Sixth, plan the timing and route. Sitting in traffic, making short trips with a cold engine and constantly stopping all raise consumption. If a longer journey is made when traffic is lighter, the saving can come without any technical tricks at all.

Conclusion

This Passat test was impressive, but it is not a guide to be copied step by step. Nearly 2,400 km on one tank was achieved thanks to an old, economical diesel engine, a brimmed fuel tank, careful technical preparation, low rolling resistance, aerodynamic tweaks, favourable weather and an extremely slow driving style.

For everyday drivers, the real lesson is simpler: keep the car healthy, use the right tyres, drive at sensible speeds and stay smooth. Most people will not reach the Arctic Circle on a single tank, but they can reduce fuel consumption — without hanging off the back of a lorry, switching off the engine or irritating everyone behind them.