Ev time!

[Yugguy1970]

I knew the Rav was efficient but 6000% of the time in EV!

🤣

 

 

[Hayzee]

Guy....it does say the data is approximate 😂

 

[Sealiedog]

I posted something similar a couple of months ago. I've not seen it again since though. I'm not sure it's that accurate at the best of times. If I get 50 mpg and I'm in EV for over 50% of the distance, does that mean the ice is doing less than 25mpg when it's on?

[ernieb]

10 hours ago, Sealiedog said:

I posted something similar a couple of months ago. I've not seen it again since though. I'm not sure it's that accurate at the best of times. If I get 50 mpg and I'm in EV for over 50% of the distance, does that mean the ice is doing less than 25mpg when it's on?

NO, look at the reported mpg figure which will be calculated on the overall miles covered. To get the ICE mpg you'll need to do some simple maths, calculate the petrol used, overall miles divided by overall mpg. Then subtract the EV miles from the overall miles and use this and the petrol used to find the ICE mpg.

[Sealiedog]

10 hours ago, ernieb said:

NO, look at the reported mpg figure which will be calculated on the overall miles covered. To get the ICE mpg you'll need to do some simple maths, calculate the petrol used, overall miles divided by overall mpg. Then subtract the EV miles from the overall miles and use this and the petrol used to find the ICE mpg.

I'm not sure I get that. If I do 50 miles at 50mpg I use 1 gallon. If 50% of the trip distance was EV I did 25 miles on the ICE for my 1 gallon didn't I? Or am I misinterpreting something?

[ernieb]

PHEV: Once you’ve calculated the overall fuel used then you need to reduce the overall mileage by the amount EV mileage which can be the traction Battery plus the recovered, whatever the MyT app gives you a %age of EV distance so what I do is then calculate the difference between the overall miles and the ‘EV’ miles and call that the ICE miles. This I then use to calculate the ICE mpg from the ICE distance and the overall fuel used. Unless I’ve got it totally wrong, whatever, it’s an indication.

Example:

Total distance 115.7miles

Overall mpg 112.1mpg (fuel used 1.03 gals)

EV distance 59% (ICE distance 41% = 47.5 miles)

ICE mpg 46.1 mpg

[Sealiedog]

20 hours ago, ernieb said:

PHEV: Once you’ve calculated the overall fuel used then you need to reduce the overall mileage by the amount EV mileage which can be the traction battery plus the recovered, whatever the MyT app gives you a %age of EV distance so what I do is then calculate the difference between the overall miles and the ‘EV’ miles and call that the ICE miles. This I then use to calculate the ICE mpg from the ICE distance and the overall fuel used. Unless I’ve got it totally wrong, whatever, it’s an indication.

Example:

Total distance 115.7miles

Overall mpg 112.1mpg (fuel used 1.03 gals)

EV distance 59% (ICE distance 41% = 47.5 miles)

ICE mpg 46.1 mpg

Your numbers seem correct, but I think mine do too? Mines an AWD HEV so less total power but the ICE is the same of course. I'm confused now.

[philip42h]

On 9/15/2022 at 9:03 PM, Sealiedog said:

I posted something similar a couple of months ago. I've not seen it again since though. I'm not sure it's that accurate at the best of times. If I get 50 mpg and I'm in EV for over 50% of the distance, does that mean the ice is doing less than 25mpg when it's on?

Ah, OK ... you have a HEV and therefore zero EV range - you have to burn petrol in the ICE to charge the Battery at all. The time / distance you are in "EV" is pretty irrelevant - it's just the way the hybrid system makes the ICE less inefficient. If you get 50 mpg that's what you have! 🙂

[Cyker]

Yeah - PHEV makes it trickier to calculate true MPG, but with a normal hybrid there's nothing else to do!

(Also, covered just under 100 miles on a new tank of fuel in my Mk4 Yaris, currently averaging 82mpg   (That won't last much longer tho'  ))

[Roy124]

Sealiedog, Philip misses an important difference between ICE and HEV, that is braking energy recovery. 

When you descend in an ICE there are two inefficiencies.  Your engine continues to consume fuel ; not much I grant but consume it does.  If you use the brakes you are converting kinetic energy to heat. 

In contrast the HEV engine shuts down and kinetic energy is converted to electric energy which recharges the Battery. 

In your example you asked if your ICE consumption was 25 mpg.  In simple terms you are spot on. You can see this on your instantaneous consumption meter. Descend a hill with engine off and you will see the consumption reading go to full scale at 150mpg.

Start the ICE and consumption immediately shoots up with the meter well below 2 scale marks. 

The meter is calibrated with 25 mpg intervals and it will typically sit near the lowest mark, generally just above the 25 mark. 

If you have a rev counter it will either read zero or around 2,000 unless climbing a hill. 

If you have a Cross the rev counter is replaced with a 3 segment display - Charge, Eco and Power.  Each segment is divided into two.  More on this later when I have explored more 

[Roy124]

In 600 miles my Yaris is getting 68 with lots of 70+

[Cyker]

It's just so mindbogglingly easy to get into the 70's with the M15A-FXE - Toyota really knocked it out of the park with this engine!

 

 

[ernieb]

I think that overall Toyota have done an amazing job with hybrid/PHEV technology over the years achieving overall pretty much what the publish unlike many of their competitors.

[Eddie G]

1 hour ago, Cyker said:

Yeah - PHEV makes it trickier to calculate true MPG, but with a normal hybrid there's nothing else to do!

(Also, covered just under 100 miles on a new tank of fuel in my Mk4 Yaris, currently averaging 82mpg   (That won't last much longer tho'  ))

Am at 66 currently but the Mk 4 Yaris is as nice to drive a tad faster as it too drive slow 😁 

[Cyker]

Totally agree! It's taken a lot of the frustration out of being stuck in long slow boring traffic for me, but is still willing when I open up the taps!   

 

[philip42h]

18 hours ago, Roy124 said:

Sealiedog, Philip misses an important difference between ICE and HEV, that is braking energy recovery.

With respect Roy, Philip misses nothing ... 😉

Sure, the hybrid system in a Toyota self-charging hybrid (the HEV) includes a kinetic energy recovery system - regenerative braking - that can convert kinetic energy to store electrical energy. But it is a relatively inefficient system - by the time you've converted it back into kinetic energy again (run the electric motors) you'll have around half the energy that you started with. Sure regenerative braking is a far better option that mechanical braking (all energy lost) but it is no where near as efficient as lifting off earlier and 'coasting'.

But the point is that the HEV has only one source of energy - the petrol you put into the tank. And the entire hybrid system depends directly or indirectly on burning that fuel in the ICE to make the car go. The hybrid system simply makes the car more efficient - Toyota haven't invented a perpetual motion machine and are still bound by the laws of physics.

The PHEV is different in that it has two sources of energy - you can put petrol into the tank and you can plug it into the mains to charge the traction Battery. The PHEV has around 47 miles EV range per full charge so, in theory at least, if you stick within it's EV range you may not burn any petrol at all. So, as Ernie points out above, you need to discount the true EV miles when calculating the mpg for the PHEV.

By contrast, the HEV has zero EV range which makes the mpg calculation much simpler - just divide the miles covered by the volume of fuel used ...

[Roy124]

25 minutes ago, philip42h said:

With respect Roy, Philip misses nothing ... 😉

I think we are actually arguing the same facts from different aspects. 

I was answering Sealiedogs question of the ICE consumption which, from observing the consumption scale, with a figure around 30 mpg. 

Using their hybrid technology they recover lots of energy and thus getting a much better mpg compared with an ICE.  I wasn't talking about PHEV at all. 

Regarding braking regeneration, it is better considered as retardation regeneration.  Braking will recover little energy and lose lots through brake heating. 

As you say, lifting off early does not waste energy but directs the kinetic into regeneration. 

The annoying thing is when you lift off at quarter mile or earlier a following car takes this as an overtaking opportunity.  Hard acceleration followed by brakes, brakes go. 

I had this yesterday, Range Rover had to get passed but immediately got baulked by two trucks. Even though he did get passed, 2 miles later at the lights I was along side him. 

Clearly lots of motorists have money to burn. 

[Cyker]

The funniest thing is when they do that then have to stop at the lights, then the lights change just as you get there and you fly past them because they have to accelerate their elephantine hausfrauenpanzer from a standstill while you're already doing 40mph  

[ernieb]

…..and with the PHEV Rav, which looks like any other Rav, you have 0-60mph of 5.7secs if you really want to make the point. Very much the Hare and the Tortoise and often they put themselves and other drivers at such risk overtaking blind.

[Roy124]

This morning, clear roads, I set the CC to 70 and it really hammered the consumption. I got 69 on a journey 4 days ago and today it dropped to 54.  The gain in average speed was just 1 mph better; 35 mph and previously 34! 

Unlike at a cruise at 60 the car never reverted to full EV.  Consumption was about 45 or so with some EV assist. 

[ernieb]

I’ve found that on a regular route I use that involves about 100 miles of the M1 that setting the cruise control to an actual speed of 60mph (64mph indicated) I get a good balance of travel time and consumption. I’ve tried setting it lower and get better fuel consumption once the ICE has kicked in but get tangled in the heavies too often. At higher speeds the obvious car brick shape hits the consumption significantly and makes generally little difference to the travel time and I’m more often having to manoeuvre and lane change.

[Roy124]

1 minute ago, ernieb said:

At higher speeds the obvious car brick shape hits the consumption significantly and makes generally little difference to the travel time and I’m more often having to manoeuvre and lane change.

Perfect example. Most trucks travel co-speed with just a few a tadge slower.  You only really need to pull out when there is a slow mover. 

 

[Cyker]

Yeah, I think MG2 doesn't have the torque and the Battery isn't big enough to sustain speeds much above 60 for any time.

I've had it run on MG2 around 70 for extended periods on a suitably long downhill section of motorway/A-road, but that's with me driving; I find with the ACC the engine prefers to run on the ICE, even at 60mph, although it will switch if you hit a downhill. It's a bit weird, as even if the power meter is only in 2-3 blocks of Eco, it often still won't switch back to MG2.

Even weirder, I've found with normal CC, the system will switch to MG2 as soon as it gets up to speed and if the torque demand drops enough (3-4 blocs of Eco or less in the power meter), so I've been experimenting with the CC more to see if it gives better mpgs on trips.

I haven't gotten much conclusive data yet tho' - The problem is, on longer trips, the ACC has made me a bit lazy, and the temptation to switch it on and let the car drive, esp. through the looooong 50-60mph roadwork sections on the M1 is too hard to resist!   (I used to get so brain-fatigued going through those sections because it's so mind-numbingly hypnotic, everyone driving in lock-step +/-3mph! The ACC takes a lot of the tedium out of it!)

 

[nlee]

Just had a week away in Scotland and it's the first time I've used a full tank of petrol without any EV charge/range remaining as a PHEV so using purely as a HEV. It's therefore the first time I could calculate true HEV mode efficiency without all the calculations. I have my fuel efficiency display set to reset on each tank fill so from full to refilling, it displayed 57.8mpg. Brim to brim calculation gave me 57.5mpg. Pretty close but also very pleasing for a 2.5L lump of a vehicle with a heavy Battery plus luggage. It's astounding really. A complete mix of rural and motorway driving, all in Normal mode.

Just to note, it wasn't through lack of public charging available that I didn't charge. I was impressed with the availability of charging (and working!) in small rural towns, mainly from Chargeplace Scotland network and fairly reasonable costs too. Our accommodation didn't have an EV charging point but it did have an external 3 pin socket. I didn't realise this so didn't pack the granny charger. Note to self for next time, just in case!