Mpg Inprovements On Yaris Hybrid

[johalareewi]

Checked over my OHs hybrid Yaris at the weekend.

The tyres are Dunlop SP Sport Fast Response (175/65R15) which are supposed to be LRR tyres but have a fuel rating of C.

In the glove box the tyre pressure sticker says 33/32, or 36/35 for ECO.

Tyre pressures were 32/31.

I have upped the tyres to 36/35 as per the sticker so will see what that does to the mpgs (and handling).

The car came from MrT so it was interesting that the pressures were not closer to 36/35.

Perhaps some of the hybrid Yaris poor mpg is down to underinflated LRR tyres direct from MrT?

[PeteB]

...The car came from MrT so it was interesting that the pressures were not closer to 36/35...

well, call me a cynic (I probably get called other things as well!), but I'm not at all surprised.

A firm that spends millions on "more wind tunnel time than any previous Toyota" [their words at the Gen 3 Prius launch] getting the drag factor down by 0.1 [a big improvement despite the small number] compared to the Gen 2 Prius, then on two out of three versions fits tyres that make it 0.1 WORSE than the Gen 2 are hardly likely to do any better with tyre pressures.

[johalareewi]

To be fair, that will be different parts of Toyota.

The wind tunnel testing will be R&D.

The 'lets stick low profile tyres on it to make it look cool' will be [uK] Marketing.

The pumping the tyres up will be local Toyota dealer.

[johalareewi]

Took the Hybrid Yaris for a long run over the weekend and was able to compare aspects of the drive with how I do it in the Prius.

The first thing was no HUD.

I never really appreciated how much it helps keep the MPGs in check.

In the Prius, the HSI is visible in the HUD so I can quickly see when I am in the PWR zone or CHG zone.

In the Yaris, the HSI is behind the steering wheel bottom left and is an analogue gauge.

So seeing whereabouts in the HSI you are is a bit more of an effort.

The second thing I noticed was acceleration.

ECO mode on the Yaris is more like normal mode on the Prius with a bit of power mode added.

The accelerator is very responsive (like a normal Yaris) so when you accelerate, it is brisk.

If you check the HSI while doing this, you are well into the PWR zone.

[barrycoll]

This HUD might help Alan...

http://www.gearbest.com/obd-diagnostic-tools/pp_32055.html?currency=GBP&gclid=CjwKEAjwm-aqBRD39YPqhbzthzYSJACFj-AtyH6voAvv9TFOrk5V7dfPXt43xgchvWg6jdoDZuxp7xoCR17w_wcB

[johalareewi]

This HUD might help Alan...

http://www.gearbest.com/obd-diagnostic-tools/pp_32055.html?currency=GBP&gclid=CjwKEAjwm-aqBRD39YPqhbzthzYSJACFj-AtyH6voAvv9TFOrk5V7dfPXt43xgchvWg6jdoDZuxp7xoCR17w_wcB

Looks interesting.

Hopefully it can handle hybrids and stop-start cars.

"Automatic power on and off: Starting with the vehicle starting, stopping with the vehicle stopping to protect the vehicle’s Battery."

I have seen a few OBDII HUD devices including smart phone apps.

Interestingly, my wife says she prefers the digital speedo she had in her previous yaris, to the analogue speedo the hybrid yaris has got.

[PeteB]

Took the Hybrid Yaris for a long run over the weekend and was able to compare aspects of the drive with how I do it in the Prius.

The first thing was no HUD.

I never really appreciated how much it helps keep the MPGs in check.

In the Prius, the HSI is visible in the HUD so I can quickly see when I am in the PWR zone or CHG zone.

In the Yaris, the HSI is behind the steering wheel bottom left and is an analogue gauge.

So seeing whereabouts in the HSI you are is a bit more of an effort.

The second thing I noticed was acceleration.

ECO mode on the Yaris is more like normal mode on the Prius with a bit of power mode added.

The accelerator is very responsive (like a normal Yaris) so when you accelerate, it is brisk.

If you check the HSI while doing this, you are well into the PWR zone.

I agree completely - I did 75 miles in a Yaris Hybrid Excel lent to me for the day while my Prius was serviced and missed the HUD immensely - I was very glad the Excel had Cruise Control so I didn't have to keep looking towards my lap for the dials quite as often.

Before buying the Prius I hadn't expected to like the HUD as much as I do now, and would hate to have a car without one - I'm not sure I like the idea of the third party one though, I already have a tyre pressure monitoring box on top of the dash, plus my Tom Tom (more or less given up with the built in SatNav now).

By paying careful attention to the HSI I did quite quickly get used to using gentler pressure on the accelerator and got the best mpg I've yet managed in a Yaris Hybrid, but still short of the Prius. I couldn't feel any difference between Normal mode and ECO through the accelerator, but presumably the latter affects the A/C and heat as it does in the Prius?

I did find it quite a chore looking so low down for the instruments though. I much prefered the old Yaris centrally mounted digital instruments. Having said all that, I did find the Yaris drove very well and I loved the single pantograph wiper (which got plenty of use in the showers today).

[Ethanedwards]

Looking at the mpg of the Yaris HSD. I usually get about 60 but simply being on holiday for two weeks. I got just under 75 to the gallon. I guess just pootling about and not having to be anywhere quickly gets me much more mpg.

[Joseph D]

Looking at the mpg of the Yaris HSD. I usually get about 60 but simply being on holiday for two weeks. I got just under 75 to the gallon. I guess just pootling about and not having to be anywhere quickly gets me much more mpg.

Who'd have thunk.

Also, going a little bit faster (5-10 mph) doesn't usually get you there that much sooner (2-3 min, or less at best), so better to be relaxed and enjoy the drive. Bonus is you have more petrol in the tank to enjoy more driving!

[dcweather]

I struggled following some of this in that I just drive normally but conservatively and let the Yaris do its own thing. I find it sometimes stays in EV up to 40 mph for reasonably long periods especially downhill. I encourage this if not much behind me and not in a rush. Are you saying this is bad for the car and mpg? I'm getting about 60 mpg around town and on a long journey with motorways, A roads and town stuff about 65mpg.

Dave

[Joseph D]

... I encourage this if not much behind me and not in a rush. Are you saying this is bad for the car and mpg? I'm getting about 60 mpg around town and on a long journey with motorways, A roads and town stuff about 65mpg.

I depends what you mean by "encourage this". Looking at your stats I'd say you're doing alright.

Trying to force the car to stay in EV longer than it wants does not hurt the car, but can be detrimental to getting good MPG stats.

You could try not going out of your way to "make" the car run on EV for a couple or three tanks and see if you get better MPG stats.

Just remember that there are many factors that affect MPG - tyres, tyre pressures, weather, terrain, driving style, etc - so to focus solely on one thing may not make too much of a difference.

The most important thing is to relax and enjoy the ride.

[Grumpy Cabbie]

Classic new owner mistake/misunderstanding.

You really do NOT want to encourage a hybrid car to stay on electric longer than it would want or normally do. It's counterintuitive as you see you're getting 100+mpg on the gauge and think that's good - and it is until you realise that the car then has to work much harder charging the Battery to put that charge back in, reducing fuel economy further overall. So that 60 mpg you're getting and thinking is good, could easily have been 75/80 mpg.

There are so many threads about this in this forum and others.

There are two little phrases I used for the Prius to explain to others;

"Just because you don't understand how it works, doesn't mean it doesn't"

"It's a petrol car with electric ASSISTANCE, not an electric car with petrol assistance"

But we come on this forum to learn, so any questions then do ask.

[Hybrid-Harry]

I have had my Excel hybrid for 6 weeks now, I have not reset the MPG on the dash since I picked it up, it's recording 64.7 MPG overall. Even though this is the car's computer readout, I have done a full to full tank test and it's within 2 MPG, but can you trust forecourt pumps to trip exactly the same, and of course the engine is still tight.

Every time I go out the first part of my journey, about 3/4 mile on a flat B road leading to a dual carraigeway roundabout it stays in EV because I don't get above 35 MPH (No driving modes are selected, it's just normal).

As I pull away onto the dual road the engine starts and continues to run for the 5 mile journey (cruise control @ 55 ish) before coming off onto an A road, It then does what it does best using both petrol & elec.

Personally I will always drive in normal mode during the summer months, in winter I might give ECO a try because of the climate control but it might not be needed as the car is garaged.

[CPN]

"It's a petrol car with electric ASSISTANCE, not an electric car with petrol assistance"

That's probably the single most important thing to appreciate and understand about hybrids...

[dcweather]

Classic new owner mistake/misunderstanding.

Y

There are two little phrases I used for the Prius to explain to others;

"Just because you don't understand how it works, doesn't mean it doesn't"

"It's a petrol car with electric ASSISTANCE, not an electric car with petrol assistance"

Without wanting to encourage being patronised - I do understand that ;-) Just saying that I run in normal mode not eco. When I say encourage I mean if I am going along at a constant 40 mph and it chooses EV, I wouldn't do anything like accelerate unless I needed to, to maintain that speed. Then if it drops out it drops out. If you are driving to be economical it does seem illogical to accelerate out of EV so that it uses less fuel later. The computer does the choosing of the mode and I drive pretty much how I would in a non-hybrid to be economical except I think I am trying a certain amount of the recommended power and glide technique but surely that encourages EV mode?

Dave

[Joseph D]

Without wanting to encourage being patronised - I do understand that ;-) Just saying that I run in normal mode not eco. When I say encourage I mean if I am going along at a constant 40 mph and it chooses EV, I wouldn't do anything like accelerate unless I needed to, to maintain that speed. Then if it drops out it drops out. If you are driving to be economical it does seem illogical to accelerate out of EV so that it uses less fuel later. The computer does the choosing of the mode and I drive pretty much how I would in a non-hybrid to be economical except I think I am trying a certain amount of the recommended power and glide technique but surely that encourages EV mode?

Dave

There is nothing wrong with how you describe the way you are driving along at 40 mph, and that is why I said it depends on what you mean by encouraging EV mode. As you describe it, you are not really encouraging EV mode. you are just driving the car and letting it decide how to provide the power.

However, in your second statement in regards to P&G, yes, you do actually want to accelerate a bit harder to kick it out of EV and use the petrol engine because any sustained amount of P&G will deplete the Battery in the long run, as you will (if you are doing it right) glide more than you pulse. Using the engine does mean it does not draw down on your Battery reserves and also gives it a bit of a charge. I stop P&G once I get down to around 4 bars and maintain a constant rate on the consumption meter so that the Battery can charge back up. I can usually keep it in the high 50's to low 60's or better while doing this.

Although this seems counter-intuitive (you yourself said it didn't seem logical), you need to do this otherwise you will use energy inefficiently charging up the battery, as the hybrid's happy place is around 6 bars.

The over-arching aim is to minimise in-flows and out-flows from the battery as each time you put energy in or take energy out you will incur losses due to the inefficiencies of converting energy from one form to another.

The best in-flow is to capture the otherwise wasted energy from decelerating (e. g. coming to stop for lights or slowing for a roundabout) and descending a hill.

Understanding this concept has changed the way I drive the hybrid and has improved my fuel economy from around 54-57 mpg to 62-65 mpg.

I apologise if we came across as patronising, it wasn't meant to be. We are all just trying to pass on what we have learned and bust a myth or two as we go.

Joseph.

[Grumpy Cabbie]

I apologise if we came across as patronising, it wasn't meant to be. We are all just trying to pass on what we have learned and bust a myth or two as we go.

Joseph.

And also because we get many new owners who ask for help, yet also tell how the car should be driven, often without searching historical threads on the very same question being asked.

Joseph gets incredible mpg's out of a bigger car that makes mid 60's to the gallon look average. I have managed high 80's and very low 90's to the gallon out of my Prius when trying very hard over tens of miles. I haven't a clue how to pulse and glide, yet I was doing something right.

We Brits need to chill out and listen to those with more experience without immediately assuming they're being insulted or patronised. I was trying to help.

[dcweather]

Without wanting to encourage being patronised - I do understand that ;-) Just saying that I run in normal mode not eco. When I say encourage I mean if I am going along at a constant 40 mph and it chooses EV, I wouldn't do anything like accelerate unless I needed to, to maintain that speed. Then if it drops out it drops out. If you are driving to be economical it does seem illogical to accelerate out of EV so that it uses less fuel later. The computer does the choosing of the mode and I drive pretty much how I would in a non-hybrid to be economical except I think I am trying a certain amount of the recommended power and glide technique but surely that encourages EV mode?

Dave

There is nothing wrong with how you describe the way you are driving along at 40 mph, and that is why I said it depends on what you mean by encouraging EV mode. As you describe it, you are not really encouraging EV mode. you are just driving the car and letting it decide how to provide the power.

However, in your second statement in regards to P&G, yes, you do actually want to accelerate a bit harder to kick it out of EV and use the petrol engine because any sustained amount of P&G will deplete the Battery in the long run, as you will (if you are doing it right) glide more than you pulse. Using the engine does mean it does not draw down on your Battery reserves and also give a bit of a charge. I stop P&G once I get down to around 4 bars and maintain a constant rate on the consumption meter so that the Battery can charge back up. I can usually keep it in the high 50's to low 60's or better while doing this.

Although this seems counter-intuitive (you yourself said it didn't seem logical), you need to do this otherwise you will use energy inefficiently charging up the battery, as the hybrid's happy place is around 6 bars.

The over-arching aim is to minimise in-flows and out-flows from the battery as each time you put energy in or take energy out you will incur losses due to the inefficiencies of converting energy from one form to another.

The best in-flow is to capture the otherwise wasted energy from decelerating (e. g. coming to stop for lights or slowing for a roundabout) and descending a hill.

Understanding this concept has changed the way I drive the hybrid and has improved my fuel economy from around 54-57 mpg to 62-65 mpg.

I apologise if we came across as patronising, it wasn't meant to be. We are all just trying to pass on what we have learned and bust a myth or two as we go.

Joseph.

Thanks for the very clear information Joseph. I seem to be finding more or less the right style, partly by trial and error and partly from reading these and an element of intuition. I didn't mean to say you were patronising me - more I was encouraging it from my somewhat vague comments. Apologies.

In terms of efficiency - given a situation where you know you have say 50 metres of braking for a roundabout, given nothing was behind or in front of me, I would normally break evenly and come to a slow stop. Would it be best to do that or brake later and harder or would it make little difference?

[Lesolee]

In terms of efficiency - given a situation where you know you have say 50 metres of braking for a roundabout, given nothing was behind or in front of me, I would normally break evenly and come to a slow stop. Would it be best to do that or brake later and harder or would it make little difference?

The charge indicator tells you how hard you are braking. If it bangs on the endstop you are braking too hard to be efficient. It is slightly more efficient to brake less hard than the maximum regenerative level (on a good theoretical basis).

[dcweather]

I apologise if we came across as patronising, it wasn't meant to be. We are all just trying to pass on what we have learned and bust a myth or two as we go.

Joseph.

And also because we get many new owners who ask for help, yet also tell how the car should be driven, often without searching historical threads on the very same question being asked.

Joseph gets incredible mpg's out of a bigger car that makes mid 60's to the gallon look average. I have managed high 80's and very low 90's to the gallon out of my Prius when trying very hard over tens of miles. I haven't a clue how to pulse and glide, yet I was doing something right.

We Brits need to chill out and listen to those with more experience without immediately assuming they're being insulted or patronised. I was trying to help.

Eh? That's the problem with online - no way did I mean that and I politely asked genuine questions :-( You have mis-interpreted my friendly comment - I should have perhaps added a smiley. I do search other threads but happened to join this as it seemed current and relevant to me. See the comment I made to Joseph before I saw this :-) Dave

[vanilla.coffee]

Classic new owner mistake/misunderstanding.

You really do NOT want to encourage a hybrid car to stay on electric longer than it would want or normally do. It's counterintuitive as you see you're getting 100+mpg on the gauge and think that's good - and it is until you realise that the car then has to work much harder charging the battery to put that charge back in, reducing fuel economy further overall. So that 60 mpg you're getting and thinking is good, could easily have been 75/80 mpg.

I am driving my Yaris hybrid exactly as you suggest I shouldn't.

And get 75-80mpg.

Now that the ambient temps are up in the U.K. I am regularly and consistently seeing 85 - 90 mpg. (Best so far 92.6mpg tankful to tankful)

The advice in the forum is helpful but as I have learnt, not always applicable to all.

My commute is 64 miles round trip each day.

I actively encourage electric only running, contrary to what the experts here suggest. (Not selecting EV mode, merely being extremely light footed on the accelerator pedal)

In another thread one member here was quite emotional in his response to me verging on the personal and insulting vibe suggesting that I was wrong.

How dare I drive my own car contrary to 'expert opinion'

The one thing beyond dispute that I know about my 'clever little car' is 2 fold.

1: If the car thinks the ice is required, it engages it.

2: Once the ice runs, 'surplus' energy is used to charge the Battery. ( Wonders how many will pay attention to the 'surplus' bit)

Here's some advice for free, sticking to the speed limit works wonders. If it says 30mph, do 30mph.

[DarrenM]

Have a like for the speed limit bit :)

I think slower speeds are the biggest bit of squeezing more out of physics. Air resistance is the enemy.

As for the experienced advice above about wanting to keep it out of EV as much as possible, it goes against what Toyota UK recommend, which is keeping it in EV as much as possible:

http://blog.toyota.co.uk/hybrid-driving-technique-toyotas-top-tips-for-achieving-the-best-fuel-economy-in-your-hybrid

9. EV does it! Keep the car in EV mode as much as possible by using the accelerator gently, pressing it lightly but consistently.

Another great hybrid driving tip is to use the car’s battery whenever possible. You can do this in town and urban driving by accelerating to your required speed, easing off the accelerator and then gently easing the accelerator on again. By doing this, you can activate EV mode – indicated by the dashboard light – which means that the engine has switched off and you are using the electric battery.

So are the people who are quite aggressively against doing this saying they know more than Toyota? I'm not saying who's right or who's wrong but saying things like we need to chill out and listen to those with more experience aren't very helpful when it's not really clear whose experience is correct, 2 guys in a forum or Toyota?

[johalareewi]

So are the people who are quite aggressively against doing this saying they know more than Toyota? I'm not saying who's right or who's wrong but saying things like we need to chill out and listen to those with more experience aren't very helpful when it's not really clear whose experience is correct, 2 guys in a forum or Toyota?

I know where my money is. ;)

Toyota GB very often don't have a clue about what goes on under the bonnet.

But with all advice on this forum (and any source for that matter). YMMV

[dcweather]

So it isn't quite as black and white as it first appeared! I will continue to experiment over time and see what works. It seems to be a fact that the recent warmer UK temperatures (our first summer with the car) do indeed make a big difference, even more than I had expected. Another thing I notice is that unsurprisingly there aren't the big fluctuations in consumption you get with conventional cars. 60-65 mpg seems to be the norm from traffic up to about 65-70 mph.

People shouldn't feel the need to put their point aggressively, we all seem to think it's a great car and all input will lead to the optimum driving style that suits the individual.

Dave

[CPN]

So it isn't quite as black and white as it first appeared! I will continue to experiment over time and see what works. It seems to be a fact that the recent warmer UK temperatures (our first summer with the car) do indeed make a big difference, even more than I had expected. Another thing I notice is that unsurprisingly there aren't the big fluctuations in consumption you get with conventional cars. 60-65 mpg seems to be the norm from traffic up to about 65-70 mph.

People shouldn't feel the need to put their point aggressively, we all seem to think it's a great car and all input will lead to the optimum driving style that suits the individual.

Dave

My own two pennyworth? I've tried both "extreme" styles of driving in my Yaris Hybrid and in both cases it can result in appalling fuel consumption figures (dependant on type of journey of course) in the high 40's mpg; which is bad for a Yaris Hybrid... My own tip? (FWIW!) Stop obsessing about the mpg figures, turn the mpg display off, either look at the satnav or the radio/audio player display instead and just drive as you would drive a normal car! Do the calculations for mpg on your next tank to tank neck fill-up and revel in the pleasant surprise! :D