2010 Prius 2ZR-FXE engine efficiency map

[Flying White Dutchman]

Originally Posted by ken1784

Please note that the 1.8L engine's rpm number, for the 40kW output, is lower (3650rpm & within 230g/kWh area) than 1.5L's (4000rpm & out of 230g/kWh area).
I believe the vehicle cruising speed by 40kW is approx 95mph, and we can see the turning point at 3650rpm to get more torque than efficiency for higher speed.
It looks Toyota is trying to compete European diesels on 90mph cruising German autobahn.

[/IMG]

90mph is just 144kmph
even that this is above the 120 here in the netherlands lots of people drive 140 here
and when you go to germany 140 is slow
you drive 150 to 180 there with a normal car.

so its not really going to try to compete

on the other hand
in germany lots of highways are going down from NO limit to 130kmph
so in that case ( and its growing ) its a nice thing for the new prius

battle the diesels

[jprates]

Originally Posted by Tideland Prius

depends on the road. I've done 65-45 on a 70km/h road. The only reason why I could do it was because it was just before rush hour so the road is fairly empty and any traffic could use the left lane to overtake me (it's two lanes each way).

Even so TP. By pulse & glide one is effectively removing one lane from the road for practical purposes. Which right does one have to limit the traffic on a 2 lane road to 1 lane only? It just does not feel right.

I hate it when people in front of me can't keep a steady speed. Anyhow, I doubt that p&g from 65-45km/h can get you much better results than cruising with CC at 60 km/h for example. At 65 km/h the efficiency of both the inverter and MG2 is maximum (~93.7% combined). On top of that, this is just bellow limit speed you can go without the ICE turning, which is beautiful.

In practical terms, the Prius will pulse with ICE on to charge the HV battery about half the time, and stealth with ICE off the rest of time. I can always get around 2.5 L/100km (94 US MPG) with this very straight forward "technique" and I don't have to bother the other drivers with annoying pulse & glide speed variations.

[jprates]

Originally Posted by Flying White Dutchman

90mph is just 144kmph
even that this is above the 120 here in the netherlands lots of people drive 140 here and when you go to germany 140 is slow you drive 150 to 180 there with a normal car.

so its not really going to try to compete

Allow me to disagree here.

We also have 120 km/h high-way speed limit here, and just like in NL most drive at 140 km/h .

By being a lot more efficient at around 90 mph the new Prius is in fact attacking the diesels strong since this is the most commonly used high-way cruising speed.

This is excellent.

[Flying White Dutchman]

Originally Posted by jprates

Allow me to disagree here.

We also have 120 km/h high-way speed limit here, and just like in NL most drives at 140 km/h .

By being a lot more efficient at around 90 mph the new Prius is in fact attacking the diesels strong since this is the most commonly used high-way cruising speed.

This is excellent.

it was about the german autobahn
thats wath i was replying to

when you look at normal driving EU speeds then yes this new prius will do a lot better on the highway

but not when competing to a diesel when driving 180-200kpmh i think on the german autobahn

[jprates]

Originally Posted by Flying White Dutchman

but not when competing to a diesel when driving 180-200kpmh i think on the german autobahn

Still not convinced here

At 180 km/h what do you think is the efficiency of a BMW 525d? Or a VW Passat TDi? What do you reckon is their consumption?

I would not bet either way!

[bwilson4web]

Could someone rent a diesel for a day and possibly run it up and down the highway at different speeds to measure the mileage?

Bob Wilson

[jprates]

Originally Posted by bwilson4web

Could someone rent a diesel for a day and possibly run it up and down the highway at different speeds to measure the mileage?

Bob Wilson

I live too far away from Germany to test this, and anyway I refuse to drive diesels, I don't drive those pollution manufacturing plants!

I always find myself amazed when I read some American folks asking for diesel cars in the US. If they only knew how terrible the emissions on those cars are... but that's a different topic.

[Flying White Dutchman]

Originally Posted by jprates

I live too far away from Germany to test this, and anyway I refuse to drive diesels, I don't drive those pollution manufacturing plants!

I always find myself amazed when I read some American folks asking for diesel cars in the US. If they only knew how terrible the emissions on those cars are... but that's a different topic.

Allow me to agree here.

[SageBrush]

Originally Posted by DaveSheremata

It's starting to boggle my mind a bit whenever I try to bounce the scalars around! (I'm probably not supposed to do that...

It looks a lot more efficient across the board - when you count out the circle to the 190g/kWh, the 2010 covers a lot more ground!

[scratching head]where are the BSFC circles below 220 ?[/scratching head]

btw, and I hope someone will correct me if I am wrong, a bsfc of 220 equals 36% engine efficiency. My read of this new engine is that it *extends* the efficient range, but maximum efficiency is little improved over the Prius G2 engine. This reinforces my earlier opinion that P&G at low speeds and avoiding high speeds puts a G2 driver in the same fuel economy ballpark as the G3. Speeds of 43 to low 50's mph might be a G3 strength though, since P&G in that speed range in the G2 is at best a pain, and often not practical.

I also get the impression that petrol engine efficiency over 40% is quite a barrier.

[Tideland Prius]

Originally Posted by jprates

Even so TP. By pulse & glide one is effectively removing one lane from the road for practical purposes. Which right does one have to limit the traffic on a 2 lane road to 1 lane only? It just does not feel right.

I hate it when people in front of me can't keep a steady speed. Anyhow, I doubt that p&g from 65-45km/h can get you much better results than cruising with CC at 60 km/h for example. At 65 km/h the efficiency of both the inverter and MG2 is maximum (~93.7% combined). On top of that, this is just bellow limit speed you can go without the ICE turning, which is beautiful.

In practical terms, the Prius will pulse with ICE on to charge the HV battery about half the time, and stealth with ICE off the rest of time. I can always get around 2.5 L/100km (94 US MPG) with this very straight forward "technique" and I don't have to bother the other drivers with annoying pulse & glide speed variations.

Oh I agree. If there is enough traffic that both lanes are decently filled, I will disguise my P&G as much as possible which means I will not be doing 65-45 or whatever range but I'll just glide as much as I can.

Sure I can cruise at 60km/h but that particular stretch of road isn't flat so I can take advantage of the ups and downs to glide. For example, I'm gliding down from 65km/h. There's a very slight downhil stretch. I know if I continue gliding, I can get up to 70km/h or more... If a car is coming up behind me, I'm not worried in this case because by the time he's caught up to me, I would already be doing 70km/h near the "bottom" of the slight downhill. Again, it's not very curvy so they can see a Prius miles away and will change lanes .

This allows me to continue to glide down and the pulse one more time before I meet them at the red light.


It works well IFF you know the design of the road, the terrain, the typical traffic volume, and the lights. It only took me a month to figure out that new route (and that route helped me get 3.9L/100km two summers ago!!).


So yes I wouldn't do it on an unknown road (or at least strictly adhere to P&G) but if it's a daily commute route, it'll be easy. You can disguise P&G and nobody will know.