One of the mysteries of motoring is why hybrids have been allowed to wallow in the Greenie/Granny car…
One of the mysteries of motoring is why hybrids have been allowed to wallow in the Greenie/Granny car category in the public mind for so long. Yes they save you a lot of fuel. But they do a lot more than that. In many ways they’re the ultimate power unit for all motoring. /1 https://t.co/dKsiRyp0Xq
Obviously a hybrid is a combination of a combustion engine (usually petrol - an ICE), and one or more electric motors. There are multiple ways to hybridise these two motor types, but it’s more important to understand why it’s done. /2
Hybrids have been around for years, and the public focus is almost entirely on their high fuel efficiency. What should have been said more years ago, is that this efficiency comes from targeting the strengths of each motor type, to compensate for the weaknesses in the other. /3
Here’s a torque/power curve for a standard petrol engine. Torque is how good the engine is at providing rotational motion (what we need to turn wheels), and power is how quickly that torque can be provided. Notice the high revs (RPM) at peak torque and power. /4 https://t.co/sDmqmbjU8j
You need to really rev an ICE to get power and torque out of it. That’s why they have gears, gears allow you to rev the engine the right amounts at different speeds, to access that sweet spot of power and torque. Try moving your car from a standing start in 3rd gear. /5
Here’s a torque/power curve for an electric motor. What should stand out is that they have maximum torque from a standing start, from 0 rpm. That’s why EVs are painfully quick in acceleration. What hybrids do is blend or hybridise these two torque/power profiles. /6 https://t.co/dde582FsUu
A hybrid will prioritise the high torque of the electric motor at lower speeds or when accelerating, allowing the vehicle to use a lot less energy to achieve the same acceleration. You don’t need to rev the guts out of it, as in a pure ICE. /7
It will use more of the ICE at higher speeds, where the electric motor’s torque drops off a bit. You can see how the two engine types have compensated beautifully for each other’s weaknesses. But it’s what this means in practice, when driving, that is stunning. /8
When you drive a well-designed hybrid, unlike in an ICE where you get that surge and wane of going up through the gears to get up to speed, as revs go up and down, in a hybrid there’s a beautifully continuous feed of maximised power and torque at every speed. /9
It’s like the car is gliding along the road. It’s continuous torque and power, no matter the driving conditions, perfectly targeted at the driving conditions of the time. It’s sublime, you’d never go back to a straight-ICE after driving a good hybrid, or I wouldn’t anyway. /10
It’s more ‘grunt’ than an ICE, the image of the pure-ICE as being the muscle, grunt option, and hybrids the granny fuel-sipping option, is just engineering BS. ICE engines are puny alone, again you have to rev the guts out of them to extract power and torque. /11
And then transmit that energy (the 20-30% that remains after the rest goes street out the exhaust as heat, unused) through a ridiculously complex series of mechanical translations between engine and wheels. Hybrids don’t need to bother with any of that. /12
Formula 1 cars are hybrids. They became much more powerful and fuel efficient (they don’t re-fuel during races now) when they switched to being hybrid. If this had been the public story about hybrids from the beginning, we’d all have been driving them years ago. /13
The fuel and therefore also money we’d have individually and nationally saved would have been astronomical. And the transition to full-EVs would have seemed a much smaller leap than what we’re facing today. /14
More power and torque (more ‘grunt’), much less fuel, and much more refined driving experience. A real missed opportunity.
(I’ve obviously had to heavily simplify a lot of the engineering here. Happy for mechanical engineers to finesse the argument!) /end