Is torque additive?  If I were to rapidly accelerate from a stop sign and both the ICE and electric engine are driving is their torque additive?  The ICE develops 105lbs and the electric motor develops 258lbs do they add to produce 363lbs of torque?

Noel 

3 hours ago, ckyliu said:

This is the case across the UK, the official figures don't look too bad but anecdotal evidence suggests unusable chargers are widely underreported.

 

To be honest, I cant really comment on "anecdotal evidence". May or may not be true. 

 

3 hours ago, ckyliu said:

but let's not kid ourselves that our charging infrastructure is anywhere near the level it needs to be

 

Its not, nobody has said it is. Improving rapidly though. And as I said, most people use their cars for short journeys, in which case they will be charging at home. The figures I gave were for US. 

For the UK...

The average distance driven is 8.4 miles. A small number of trips are over 100 miles, where chargers might be required for lower range EV's. 

 

 

17 minutes ago, birdguy said:

Is torque additive?  If I were to rapidly accelerate from a stop sign and both the ICE and electric engine are driving is their torque additive?  The ICE develops 105lbs and the electric motor develops 258lbs do they add to produce 363lbs of torque?

Noel 

 

 I believe the way it usually works for regular cars is that the electrics are engaged for economy, light acceleration, and when you put your foot down its all ICE. 

Varies dependant on the car though. Some sporty hyper cars use both the ICE and electric for performance. Different philosophy, rather than electric for economy its electric for performance boost. 

Aston Martin's Valkyrie uses a system  were its stores the energy of braking and uses it for acceleration boost. 

Ferrari SF90 uses the electrics to add an additional 217 bhp. 

No expert though. Rob may know more.

 

Edited March 18, 20224 yr by martin-w

25 minutes ago, martin-w said:

and when you put your foot down its all ICE. 

When I put my foot down the graphic on the dash shows both motors driving the wheels.

Noel

Not sure how it works for Prius then Noel, I'd have to Google it

Good article here...

https://exclusivelyhybrid.com/how-does-a-prius-work/#:~:text=The Toyota Prius has a,wheels to charge the generator.

 

"Hybrid engines typically come in series or parallel. In a series hybrid, the gasoline engine charges the car’s battery which powers the electric motor. The gas does not power the wheels directly. In parallel hybrid engines, the vehicle can receive power from the electric motor, gasoline engine, or both."

"The Toyota Prius uses the best components of series and parallel engines, making it a series-parallel hybrid.

The Prius has a power split device, which includes a gearbox connecting the generator, gas engine, and electric motor. The Prius Gen 2 was the first to have this device."

 

Edited March 18, 20224 yr by martin-w

32 minutes ago, birdguy said:

When I put my foot down the graphic on the dash shows both motors driving the wheels.

This is rather model-specific. Fortunately, I test drove a Prius (at Toyota do Brazil facilities) and I could see the same behavior you describe. The engineers there confirmed me this behavior is intended, and the electric-to-ICE power share ratio variable, depending on lots of variables (all coded into the ECU). Don´t be surprised if, on a cold winter day, your combustion engine turns on in situations you know it's ICE only: sometimes it's just to make the heater work.

Edited March 18, 20224 yr by Luis Hernandez

Thanks @Rob_Ainscough, the Mazda is a complete hoot, I just wish it had another 20 hp to make overtaking easier! I generally don't struggle for sufficient RPM though, redline all the way (at least until third gear explodes anyway) 😅 but in all seriousness having driven turbocharged engines for many years previously I fully understand the benefits of just having torque on tap whenever you want it, I had to reaquainted myself with planning for when I will need power and downshift accordingly.

You are definitely right with hypercars, electric hybridity has unleashed previously unheard of performance but their electric only range is generally poor as the batteries are small.

I know I will end up going electric eventually so I intend to have my fun with normally aspirated engine, manual gearbox, low weight and RWD limited-slip differential whilst I can! Electric cars are better on paper in almost every way but there's a clinicalness and soullessness to them that removes driver involvement, enjoyment and skill. ICE cars will go the way of horses and steam trains, purely a leisure pursuit.

EDIT: Interestingly, Toyota are working on a system that will immitate the feel of driving a petrol engined manual transmission, in an electric car https://www.roadandtrack.com/news/a39056078/toyota-patented-a-manual-transmission-simulator-for-evs/

Edited March 18, 20224 yr by ckyliu

1 hour ago, birdguy said:

Is torque additive?  If I were to rapidly accelerate from a stop sign and both the ICE and electric engine are driving is their torque additive?  The ICE develops 105lbs and the electric motor develops 258lbs do they add to produce 363lbs of torque?

  Generally they are additive.

1 hour ago, martin-w said:

I believe the way it usually works for regular cars is that the electrics are engaged for economy, light acceleration, and when you put your foot down its all ICE.

Hybrids come in many different flavours. And whether it's sequential or cumulative power and torque depends on the manufacturer, but most are cumulative. Generally cars are parallel hybrids whereby the ICE has a direct link to the wheels through an automatic gearbox, the electric motor generally feeding into the same gearbox and the power and torque is additive/cumulative. Volvo bus and truck hybrid is a notable exception, the electric motor gets you up to above 10 mph then ICE takes over.

The other method is "series hybrid" whereby all propulsion is done by the electric motor, the ICE feeds power to the battery or electric motor (like a diesel-electric railway locomotive), these are often known as "range extender" electric cars and are available on some models like BMW's i3. In this case the power and torque is not additive, since the engine cannot drive the wheels directly.

----------

At the "top end" you have a "plug-in electric hybrid vehicle" (PHEV) these usually have a fairly beefy electric motor that covers most daily driving needs; e.g. V.A.G.'s current 200 bhp PHEV platform provides 115 bhp from the electric motor alone, the 1.4L turbo engine will only start if you need more than that or the battery is becoming depleted - the electric only range is about 30 real world miles (50 km). The power and torque on this is additive. You'd think total system output of 200 bhp makes for a rapid car but the cars using the platform weigh from 1.5 tonnes so it's somewhat blunted, an equivalent iCE only is under 1.3 tonnes.

In the middle you "self-charging hybrids" as Toyota PR likes to spin it, generally the electric-only range on these is a pitiful 3-10 miles and only up to about 30-40 mph (50-70 kph) as the battery small (typically 1 kWh) although as a consequence they are a bit lighter; a Prius is around 1.4 tonnes. Similarly they usually drive through an automatic gearbox with cumulative power+torque.

Finally you have "mild hybrids" like the Fiat 500 someone mentioned earlier. They usually have a 48v alternator/motor that captures energy during braking and stores it in a small battery or super capacitor, then uses it to provide a boost during acceleration. These are incapable of driving the car on electric alone and aren't really hybrid at all in my opinion, most of the captured energy ends up being used to drive accessories. Often these are equipped with manual gearboxes.

Edited March 18, 20224 yr by ckyliu

2 hours ago, Luis Hernandez said:

sometimes it's just to make the heater work.

That's what happens when I start it on cold mornings.  Normally it's the electric motor that creeps the car when I back out of my driveway.  But on cold mornings the ICE starts immediately and runs until it warms up.  

BTW, the Prius has a unique cooling system.  It includes a thermos to store hot water after the engine is shut down and keeps it warm so when the engine stats again warm water is fed into it.  On a cold day I can shop for an hour and when I go back to the car and start it the heater works almost right away.

Here's how it works: http://john1701a.com/prius/presentations/2004-prius_tech-presentation_38.htm

2 hours ago, Rob_Ainscough said:

You Hooligan!!  I thought you didn't do crazy stuff like that

I've done it in traffic to merge into an open slot

 

2 hours ago, ckyliu said:

Generally cars are parallel hybrids whereby the ICE has a direct link to the wheels through an automatic gearbox, the electric motor generally feeding into the same gearbox and the power and torque is additive/cumulative.

It's a planetary gear system with no shifting points.  I don't understand how it works myself but it is petty smooth.  Unless I look at the graphic I don't know what's doing what at any particular time.

I know I like my Prius a lot.  I'm on my third one.  I just paid off the lease and the Limited Edition which I have is asking almost the same price used as it was listed for in 2019.  About 30,000 dollars.  Mine only has 2,200 miles on it.  I also bought the Toyota extended warrantee and service contract for another 5 years.  It's transferrable so if we ever have to sell it for some reason that adds to the value. 

The CO2 emissions is listed as 170gm/mi.  Since my trips are less than 10 miles and only once or twice a week I don't feel like I am contributing a lot.

I'm quite satisfied keeping this Prius for quite some time.  No electric in the near future for me.

One more question.  I suppose the heaters must be electric heaters in electric cars.  Are they powered by the 12 volt batter or the drive battery?

For Charlie:  How's this for getting back on topic?

Noel

 

6 hours ago, birdguy said:

Here's how it works: http://john1701a.com/prius/presentations/2004-prius_tech-presentation_38.htm

Thanks for your info! I had some annotations during my training/test drive (on a 2018 Prius), but I left them at my office. But I don´t remember having seen this heat storage system.

 

6 hours ago, birdguy said:

One more question.  I suppose the heaters must be electric heaters in electric cars.  Are they powered by the 12 volt batter or the drive battery?

Electric resistive heaters are rather inefficient. Since these cars have no ICE, they have to use a heat pump...just a fancy name for a typical A/C system working backwards. If you have an electric A/C in your house that also works as a heater, the principle is the same. The compressor in the A/C system is powered by the drive battery; the 12 V batt is not so strong. See slide 8 in the link you gave me. The orange wire confirms it

 

6 hours ago, birdguy said:

It's a planetary gear system with no shifting points.  I don't understand how it works myself but it is petty smooth.  Unless I look at the graphic I don't know what's doing what at any particular time.

Slide 25, if you feel curious. I've always had a hard time understanding how does a planetary gear system work (and I'm a mechanical engineer 😂). I used to know that some12 years ago, but I can´t remember now. All I understand is that this gear system allows you to mix nice and smoothly two input speeds and get a final output speed.

Oh, Luis, I looked at plate 25 and it just confused me.  I'll settle for just knowing it works.

Noel

Charting the cost of gasoline versus charging an electric vehicle.  The EV wins.

https://www.cnbc.com/2022/03/19/cost-of-charging-ev-vs-gas-prices.html

But I'll still hang on to my Prius.

Noel

Edited March 19, 20224 yr by birdguy

11 hours ago, Rob_Ainscough said:

and the brake pads lasted 200,000 miles

 

How long did the brake discs last? Rotors as you call them in the US. I bet not long, due to rust and pistons seizing. 😀 I'm guessing that might be the case with an EV too, unless care is taken to give the brakes a decent workout. 

Edited March 20, 20224 yr by martin-w

They fit drum brakes to a lot of BEVs for that exact reason, at least on the rear axle. They are more tolerant of light and infrequent use, and they provide all the braking power required.