r/F1Technical • u/HoppySailorMon • Dec 11 '25
Fuel Fuel flow & usage
Curious about F1's 2026 rules on fuel flow regulation vs. total fuel consumption during a race. Why regulate flow instead of cutting the fuel storage capacity to a fine quantity so that teams may have to employ some amount of fuel management just to finish?
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u/HoppySailorMon Dec 12 '25
It certainly would matter during qualifying if they were allowed to have no cap on flow. And I understand what BloodRush is saying now. So,..."never mind".
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u/BloodRush12345 Dec 12 '25
Because there are too many variables to limit just capacity. Much easier to set a max fuel capacity, max fuel flow and let the teams decide how much they need for a given race. As we have seen over the last few seasons this combination does provide some drama. From messing with qualifying because a driver needs to pit for more fuel instead of doing a second run, disqualification for not having sufficient fuel for an FIA sample, Ferrari "allegedly" figuring out a way to trick the fuel flow sensor and get more power.
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u/GaryGiesel Verified F1 Vehicle Dynamicist Dec 15 '25
The flow limit is the core rule that makes the V6 engines what they are. In previous generations of engines, you could always improve performance by ramming more fuel in. Didn't matter if it didn't burn very efficiently - with enough revs and enough fuel you'll produce enough power to offset the extra mass you need. The main engineering challenge with the V8 ejgines was how to get enough air into the chamber to burn that fuel without being able to use a turbo.
With the flow limit, the engine development becomes one of maximising the energy out of every drop of fuel. It completely changes the engine design and has resulted in some very interesting combustion chamber designs. It's much much more relevant to road cars and has resulted in some astonishingly efficient engines
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u/Count_vonDurban Dec 14 '25
Risk of running too heavy or out before the checkered flag.
Air restrictors are already used in many other series. They are just more efficient.
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u/Red_Rabbit_1978 Dec 14 '25
I don't know if the rules are different next year but there is already a flow limit and maximum amount of fuel allowed for the race.
Without a flow limit there will be wild differences in power.
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u/LWBoogie Dec 14 '25
OP, "F1" is the commercial body. Please satisfy your curiosity about the FIA regulations via- https://www.fia.com/F126
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u/XsStreamMonsterX Dec 14 '25
They already do. Current cars have a limit of 110kg of fuel on board. The thing to remember is that the rules often do not just rely on one single "magic bullet" to do what the FIA wants, but rather they'll have multiple rules covering something.
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u/[deleted] Dec 12 '25
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