На последовательнм гибриде ДВС работает в его наиболее эффективных и экономичных режимах, больше времени на постоянных оборотах, меньше на переходных режимах и на холостых. Там нет КПП и гидротрансформатора которые тоже съедают часть энергии ДВС, там можно кратковременно получить динамику и разгон для которых пришлось бы ставить ДВС в два раза большей мощности, и несомненно экономия топлива на последовательнм гибриде есть, может конечно не так как пишут в рекламе но гораздо больше чем 2%.
Мне верить не надо. Но вот чисто из спортивного интереса поболтал с искуственным интеллектом. Сначала он тоже грузил экономией 20-40%. После серии наводящих вопросов экономия упала почти до нуля. Более менее существенную экономию можно получить ТОЛЬКО двигаясь в пробке с постоянными торможениями и скоростью не более 20-30 км/ч. Ниже моя переписка.
HEV can not safe lot of energy : the battery is very small in HEV like lexus. And modern car with petrol engine have start-stop system. How HEV can safe 20-40 % of fuel? Its look like best case scenario only 3-5 % ?
Yes — your skepticism is justified, and I overstated the 25–40% figure as a general real-world advantage. For a modern petrol car with good start-stop, the comparison is much closer.
The interesting question is: how can the LBX save more than 3–5% if its battery is tiny?
The answer is that the battery doesn't need to store much energy. It only needs to capture and reuse energy repeatedly.
The key is not battery capacity — it's battery turnover
Suppose the LBX battery can temporarily store only a small amount of energy.
During one braking event:
car's kinetic energy → battery
Then at the next acceleration:
battery → wheels
Then brake again:
wheels → battery
The same small battery can cycle many times during a city trip.
It's like a small bucket collecting rain. The bucket doesn't need to hold all the rain that falls during the day; it just needs to empty and refill repeatedly.
But you're absolutely right about start-stop. A modern petrol car already eliminates much of the old hybrid advantage there.
So where does the LBX's remaining advantage come from?
There are three important mechanisms:
1. Regenerative braking
This is probably the biggest difference.
A conventional petrol car with start-stop still loses virtually all braking energy as heat. The LBX recovers part of it.
2. The petrol engine can operate at a more favorable load
This is more subtle.
The LBX doesn't necessarily run the engine whenever the wheels demand power. The hybrid system can choose:
"I'll run the engine now at a reasonably efficient load and use some of the energy to charge the battery."
Then:
"I don't need the engine now — I'll use the battery."
This is particularly useful in urban driving where power demand changes constantly.
3. The LBX's engine itself is exceptionally efficient
This is important in our comparison. The LBX isn't a mediocre petrol engine plus a hybrid system.
Lexus specifically designed its 1.5L engine for high thermal efficiency, with high-speed combustion, low friction, variable cooling, etc.
But let's quantify your 3–5% hypothesis
Suppose we compare:
Modern petrol equivalent: 5.5 L/100 km
LBX: 5.0 L/100 km
That's only:
9% saving.
If petrol is 7 ₪/L:
Petrol: 38.5 ₪/100 km
LBX: 35 ₪/100 km
Saving: 3.5 ₪/100 km
That's actually quite plausible for mixed/highway driving.
But in heavy urban traffic, a modern petrol car might consume 7–8 L/100 km while the LBX could be around 4.5–5.0.
Then the difference becomes 30–40%.
So the important point is:
HEV doesn't automatically save 20–40%. The advantage depends heavily on the baseline petrol car and driving cycle.
And Lexus itself says the LBX can operate in EV mode for up to 50% of driving time under average urban conditions, not 50% of the energy.
And there's one more thing I'd correct from my previous answer
I implied that the tiny battery somehow stores a large amount of energy. It doesn't.
The LBX battery is primarily an energy-buffer, not an energy-storage system like an EV or PHEV. Lexus describes it as a compact, high-output NiMH battery designed for quick power delivery and energy recuperation.
So I think your intuition is basically right:
For a modern, efficient petrol car with good start-stop, the LBX's advantage might indeed be only ~5–15% in some conditions.
The 20–40% figure becomes realistic mainly when comparing urban stop/start driving against a conventional petrol vehicle that has higher urban consumption, not against the very best modern petrol powertrains.
If you want, I can do a proper physics-based comparison of the LBX vs a modern 1.5L petrol car over a 10-km urban cycle, including
how many kWh are actually recoverable from braking. That would answer whether 20%, 10%, or 5% is physically realistic.
So, realistic, the safe above 20% is is feasibly only in case heavy urban traffic with speed below 10 km/h?
Yes — roughly, but I would widen the condition somewhat.
For a modern petrol car that already has good start-stop, I would regard >20% fuel saving from a conventional HEV as plausible mainly in genuinely stop-and-go urban driving, where there is frequent braking and acceleration.
But it doesn't have to be below 10 km/h. For example:
Heavy stop/go, average 10–20 km/h: HEV can potentially save 20–30%+
Urban traffic, average 20–30 km/h: roughly 10–20%
Urban flowing traffic, 30–50 km/h: often 5–15%
Open road/highway: typically 0–10%, and sometimes essentially no advantage
The crucial variable isn't really the average speed. It's how much acceleration/deceleration occurs.
