Timelines · Formula 1 · 7 of 7
Half the fuel, more power: the racing car became the most efficient engine on Earth.
2014·Mercedes PU106A: 1.6 L V6 turbo + MGU-K + MGU-H + battery·~750 hp combined (ICE ~600 + 160 electric)·2014: 16 wins in 19 races; both titles (Hamilton)·>40% in 2014 — >50% achieved by 2017
· THE STORY
In 2014 Formula 1 rebuilt the engine as a “power unit”: a small turbo V6 joined by two electric motor-generators — one harvesting energy from braking, one from the turbocharger itself — feeding a battery. The Mercedes W05 mastered the formula first and utterly: energy that every previous racing car wasted as heat now comes back out as lap time, and these engines convert fuel to work more efficiently than any other piston engine ever built.
· WHY IT MATTERED
The MGU-K motor on the crankshaft turns into a generator when the driver brakes, banking up to 120 kW into the battery instead of cooking the rear discs — then gives it back as electric push on the next straight. Watch the flows reverse in the demo as the lap phase changes.
· WHY IT MATTERED
The MGU-H sits on the turbo shaft and milks the exhaust turbine for electricity — energy recovery with no braking needed at all. It also spins the compressor up electrically, erasing turbo lag. It is the J58’s lesson from this site’s jet section — never waste exhaust energy — perfected.
· WHY IT MATTERED
Fuel was capped at 100 kg per race and 100 kg/h of flow, so the fastest car was by definition the most efficient one. The 2014 rules dragged thermal efficiency from ~29% to over 40% — beyond 50% on the dyno since — numbers no road engine and no previous racing engine had touched.
· TRY IT
Pick a phase of the lap and follow the kilowatts. On the straight the battery and engine push together; under braking the MGU-K becomes a generator and the rear axle recharges the battery; and all the while the MGU-H quietly taxes the exhaust. This flow diagram is the whole hybrid era.
Cycle the three phases and watch the teal arrows reverse: energy that every earlier F1 car dumped as brake heat and exhaust noise now loops through the battery and comes back as push. With fuel capped at 100 kg per race, recovering it wasn’t optional — it was the game.
Timelines · Formula 1 · component · Mercedes W05
A motor on the turbo shaft: harvests the exhaust, deletes turbo lag.
On the turbo shaft, turbine-to-compressor·100 000–125 000 rpm·Unlimited by rule — the efficiency battleground·Removed in the 2026 regulations
· WHAT IT DOES
Between the turbocharger’s turbine and compressor sits a slim electric machine spinning with them at over 100 000 rpm: the MGU-H (H for heat). When the exhaust drives the turbine harder than the compressor needs, the surplus becomes electricity. And when the driver wants boost NOW, it runs backwards — spinning the compressor up electrically before the exhaust could. The BT52’s one-second lag becomes a rounding error.
· WHY IT MATTERS
Roughly a third of the fuel’s energy leaves down the exhaust pipe. The turbine was already recovering some; the MGU-H takes the rest of the surplus as electricity — and by rule its harvest is unlimited, which made it the efficiency battleground of the hybrid era.
· WHY IT MATTERS
Forty years of turbo lag ended with a motor: the demo compares the exhaust-only spool of a 1983 turbo with the MGU-H spinning the same compressor up in about a tenth of a second. Throttle response like a naturally aspirated engine, boost like a turbo.
· WHY IT MATTERS
The MGU-H is widely called the cleverest and most expensive component of the hybrid era — a key reason these engines pass 50% thermal efficiency, and so complex it deterred new manufacturers. It is dropped from the 2026 rules; its decade was this one.
· TRY IT
Watch the boost response with the MGU-H off — the 1983 wait — then let it spin the compressor electrically. The second slider taxes the exhaust for electricity and shows why “unlimited harvest” made this small motor the most fought-over part in the sport.
Anti-lag and a private, uncapped energy supply from gas every previous engine threw away — one motor, both jobs. Mastering this machine is a large part of why Mercedes won everything from 2014, and its complexity is why the 2026 rules delete it.