About the Toyota Yaris Hybrid (In US Prius C)
 

I took delivery of a brand new one today, only 11 km on the clock, and as it seems to be the first of it's kind at Ecomodder, I'll bring our experinces with the car in this thread the coming months.

http://photo.netcarshow.com/Toyota-Y...3_photo_14.jpg

Some basic data:
Toyota Yaris Hybrid H1 (Basic equipment level, yet includes electric windows and mirrors, central locking system, AC klimate control, discs brakes on all four wheels, radio, driving computer.
My model is a cargo version without back seats. (Dont need them, saves weight and money)

Curb weight: 1.070 kg.
LED driving lights for day use.
Lenght: 3,9 m
With: 1,69 m
Height: 1,51 m
Power: 100 HK
Wheels: 175/65/R15 steelies

Hybrid / gas / electric
CVT auto transmission
Regens when you lift off the speeder or touch the breake.
Aukku for electric engine, Nickel-metal-hydride, 6,5 Ah, 144 volts => 936 Wh.

Front, back, and around c-pillar somewhat different body work to the Prius C.
Cv = 0,29

Compared to the Yaris P1 from 1999 theres been done a lot of areo work on the body.

http://img2.netcarshow.com/Toyota-Ya...llpaper_1f.jpg

First impressions:
This car is a delight to drive. Silent, smooth, and the hybrid drive system is amazing. I'm able to go up to 70 - 80 km/t on electric alone as long as the E-moter has the power to pull the car.

http://img2.netcarshow.com/Toyota-Ya...llpaper_33.jpg

Left on the instrumentation is the power meeter, and gas engine klicks in about wehre the needel get to the C in ECO. But not for at long distance. Depending on other power draws such as light, AC etc. 1 - 2 km's.

But really that's a lot. City driving under 60 km/t is pure electric for as long the 936 watt reaches. But it regens a lot.

Not mods yet - going to establish a baseline first, and learn how best to drive the car, execpt for adding more air in the tires (2,8 Bar)

Planned mods:
Soother wheelcovers
Grill block, upper and lower
Deflector for wiperarm
Folding right hand side mirror (can't dispose of it)

http://img2.netcarshow.com/Toyota-Ya...llpaper_40.jpg

All photos model photos so far, as wheather was bad today.

More to come the following days, weeks, months etc.....

No rear seats you say? I had removed mines for some time for more cargo room and people thought I was crazy. :eek:

Some further observations, from todays driving.
- ICE allways kick in at 73 km/h no matter what. So up to that limit coasting i best done in EV-mode if conditions allow for it, that is flat og down hill so EV motor has enough power to pull the car.
After 73 km/h coasting engine on i N is the easiest way.
ECO button alters speeder reaction, like lowering engine RPM's 500 or so.
At 85 km/t engine is hovering about 1.500 rpm, and FE is the around 3 - 4.5 liter to a 100 km.

I'm very impressed by this car. It's soo smooth to drive. ECO mode is really for calm driving. Car much more responsive in Powermode, but it also cost fules, at Rpm's go up. Shifting between EV drive and ICE drive is very smooth, sometine I don't notice it when the ICE starts.

I can get just under 1,8 - 2 km in EV at 50 km/t, which suits me well at 50 km/t is the general city speedlimit here.

I also noticed that using the AC - no surprice - causes the ICE to run a lot more - same goes for high beam on the front lights. So one clue to get better FE - more EV driving - in this car is to reduce electric loads.

Gonna look for LED bulbs for the rear lights and rear licenceplate light...

Keep it hot
 

I've now done about a 1.000 miles in the car, and found out that it like to keep it's engine warm. So do I, as we have had a cold spell here with down to minus 10 deg. C lately. Here is at 55 deg. noth latitude.
I've had problem with getting ehough heat in the cabin om trips below 10 km's, so in colder climates a grill block is a must in the Yars hybrid. I made a temporary one with foam for isolating pipes.

Secondly - the more one uses electric devices in the car, the more the ICE will run, and that off course uses fuel. So to get better milage keep AC off, keep the heatet seats off.

As for driving lights - mandatory here - the pre installed driving lights - LED's in front, no light in rear, seem to be the least power consuming.

Driving in the dark with normal lights on naturaly takes more elctric power, and causes the ICE to run more often.

If one has the possibility to install and run a block heater, I would highly reccomend it. A warm engine is a must for really good milage in this car.
As I can not use a block heater, I'll wil - as soon as a baseline of 3.500 km's driving is done, persue other ways of keeping the engine warm, and minimise heatlosses form the engine bay. (Grill blocking, sealing engine compartment etc.)

The car is by all means a real joy to drive, and so far I very happy with the buy.

More to come when the wheater has become better, and the baseline is etablished.

That is excellent mileage while breaking the car in during a cold spell!

May I suggest adding an UltraGauge or ScanGauge?
Then you can block the grill in earnest, as you can monitor air intake and coolant temperature so you'll know when you are overdoing it.

I ran some time with a full lower grill and partial upper grill block. It made the engine run warm, to about 92 degrees Celsius.
The thermostat opens flow to the radiator partially at 80 C, and fully at 90 C.

A severe storm blew away one of my foam pipe insulation tubes and it went down to 80-82 C, and took longer to heat up. FE suffered too.

I now have two clear plastic pieces over my upper grill and the remaining tubes below, now temp hovers just below 90C. FE went up. But I need to block some more ;)

OK - I've got my Scangauge II installed, think I forgot to mention. I've got to figure out where the cooling element for the hybrid drive is situated amd ditto for the AC, before doing a full and more permanet grill block.
Reason for retaining as much heat as possible is to keep cabin warrm, and to keep engine warm. When doing EV mode, the engine cools down much to rapid when heat and fan is on, so ICE start up again too soon.
This will ofcourse improve as wheater gets warmer.

Same observation with the Prius C. Two kays max. Wish I'd had more time with that car during the test, to see how much more you could squeeze from it, given proper driving.

I run a full grill block on my 2004 Prius in the winter. Nothing is going to overheat. I take out one pipe insulation strip if I have a long highway trip. I also take out one or two in summer. That is plenty of cooling. I agree, a warm engine is key for good fuel economy in the Prius.

Todays fill was a bit better than the two previous ones. My first goal was to hit the EU avarage on spritmonitor.de which for a long time was 5.1 liter / 100 km.
This is the same as 46.12 MPG US, så I've allready passed that, as I'm now on 46. someting Mpg, and still braking the car in.
Only mods so far is two foamstrips as a temporary lower grill block, and that helped this last tank. Kept engine warmer for longer. Tires at 2,9 bar.
Think baseline will be established at about 3.500 km - 3 more fills from now.
Next goal is to get to the 50 Mpg EPA avarage. The EU rating is 28,35 km/l (66.68 mpg us) which I'll only get on a warm sommer day with a hafty tailwind :) or with a good deal of mods.
Dealer said, that avarage for the car among their coustomers was around 22 km/l (52 mpg), and not to expect mouh more. In time with mods and driving style, I hope for some more. Long time goal will be the 55 - 65 Mpg tank avarage.
As Im now on winter tires, a good deal of better milage will depend on the stock summer tires that came with car. Havent tried those yet.

I find that my summer tires give worse economy than my winter tires in the same circumstances, which is only logical as they are a lot stiffer, wider and on 16 inch rims.
But they will stay intact when it gets really hot ;) and then of course the economy is much better.

Baseline est. Let modding begin!
 

This last tank I broke the 50 mpg mark, and I belive tha car here just under 3.000 km's is now broken in, and the baseline is areound the 48 - 49 mpg.

So modding begins:

- First the standard "racer look" hubcaps hit the bin, and some aftermarked more smoot ones are now mounted.

http://i940.photobucket.com/albums/a...g?t=1393745479

Seceondly, I've sealed with wheaterstrips on top of the headlights in both sides, as there was a small gap here where air could get in to the enginebay.

http://i940.photobucket.com/albums/a...g?t=1393745473

After that I placed a stiff thin form board with relfexive alu down, on top of engive inside the hood. Idear is to trap heat, so that the engine takes longer to cool down. This works great.

http://i940.photobucket.com/albums/a...g?t=1393745464[/url]

Last - I did an upper grill block, It's just a small opening, so I just stuffed some foam in there and covered the whole thing in black PVC tape. Hard to see at all standing next to the car.

http://i940.photobucket.com/albums/a...psff929c16.jpg

All of the above was done today, and testdriving showed that IEC intake temp doubled fra 6 to 12 deg C, and engine temp vent from 86 to 89 deg. C.

Too early to say anything about milage, but the butt-o-meter tells me it glides a bit better, and that wind noise is a bit lower.

As temperatures rises here as spring come along, I'll see what to do about the lower grill block, which is just temporary done, with some pipe isolation. Ive got to see if I can block more or need to remove some the keep engine temps at the right levels.

With warmer wheater I also expect to see better milage the coming months. First goal is 22 km/l (52 mpg) - which I hope to get on this tank, and long time goal will be 25 km/l. (59 mpg).

Car still looks total OEM, temporary lower gill block excluded.

FWIW, I have always driven with the REAR seats down/reclined in all of my fastback/station wagon vehicles for instant "covered" pickup utility...but, also for easier rear-view visibility (no headrests blocking vision).

Gliding
 

Apart from retaining heat in the engine when ICE is off, gliding is key to good milage in the Yaris Hybrid.
It took me a long time to figure out how it's best done, but now that I've found to teknique it's quite easy and effective.

As on whiches to enter a glide, ease off the speeder to the point where neither ICE og EV motor is pulling. It's a bit different depending on the speed, but usually on the "ECO" meter it just below the on on ECO on the meter.
Keeping the needle there the car will glide.

http://i940.photobucket.com/albums/a...ps4affa2fd.jpg

On the left meeter, between CHG and E in ECO is the zone where the can can enter a glide. Nearer to the E than to the C.

And it glides well, and it acounts for some of the improved milage on the last tank.

Pulse and glide is the key to good city and lower speed driving in the Prius. Depending on your route, you'll gain at least a few MPG's when you get it figured out. It became second nature to me before I got my Insight, now I have to think about it a little (I try to do stead speed in lean burn in the Insight).

I like that analog gauge cluster. Digital can look pretty neat, but there's nothing like watching a needle sweep as you accelerate.

Thats about the same for the insight. You need to apply light pressure on the throttle, just enough to remove the play so it is not assisting, not regen braking or in EV mode. :confused: Yes, light throttle will engage the IMA system only, maybe its an easter egg? That allows you to coast as best you can, however you are still spinning the engine, but the valves are closed.

It only spins the eninge in coasting if going faster than 73 km/t. Lower than that, ICE stops. If for instance gliding downhill, and going faster than 73 km/t ICE will fire up again. It has to spin to remove heat from the Hyperdrive :)

The inverter has a manual coolant pump? I know those who back feed the hybrid battery have to be careful of how full they try to make it as once hte SOC climbs above a certain % it also uses one of the electric motors to spin the ice to burn off the excess charge. :eek:

I wouldnt mind one one day to play with. Lots of mods for the gen 2 prius out there.

Nope, both systems are so different that they are hard to compare.
The HSD gearbox is a planetary gear system where the electric motors/generators operate different gear-rings than the ICE.
These rings and shafts can be locked in different ways to produce 3 physical gears for the engine.
It also allows the electric system to operate independently of the engine.
In fact they do that all the time to simulate gears in between the fixed ones, by making one motor work as a generator to power the other.
The battery can smoothen it out further by storing or adding power. This way the HSD system can finely regulate the amount of torque it puts out, hence the smooth deployment of power.

The Honda IMA system has the single motor/generator bolted to the crankshaft, as a flywheell. When driving at a constant load it will not do much, just generate a bit to keep the electric systems powered.
When coasting the engine cuts and the generator will store some energy in the battery. To glide it neutrally you just have to press the accelerator ever so slightly to make the charge needle move out of the green zone.

Cutting the ICE means the IMA electric motor has to take over at once, so this system cannot make the transition as smooth as the HSD system does, where the torque stays the same (even though the electric power consumption does change).

Better milage
 

The last tank gave 52,6 mpg, so the mods really made some difference. I also changed the stock stick antenna for a cheap chineese sharkfinn one. Works fine. Bought on Aliexpress for 8 dollars.
It's irritaded me from the very beginning that the car had a stick antanna adding wind resistance.
Temps are rising, and spring is hopefylly on its way.
Looking foreward to see what influence summertires will have om mpg. Hopefully good.

I've been reading your results with your new Toyota, and I begin thinking about comparisons with our new one, a 2013 Tundra 4x4 double Cab pick up. We filled our first tank last Friday and got 18.3, just figuring miles and gallons added. Our truck figures out to be almost 2 1/2 times heavier than your car, with a frontal area about 1 1/2 times as large, obviously ours is not a Hybrid, with a 5.7 liter V-5 @ 381 HP. Ours has DOHC, dual Variable Valve Timing, and is E-85 Flex Fuel rated, with a 6 speed auto transmission, and a 4.3 to 1 rear axle ratio. I drive normal, coasting to Stop signs and Red lights, but do not P&G, or drive less than the speed limit, which here is 75 mph on the highway. It will be interesting to follow our progress!

My milage is not impressive at all considering the car. But is due to a very irrattic drive pattern, with lots of short trips, and then some long ones. Many on a rather cold engine. (Why perserving heat is of importance to me).
Our cilmate is cold half of the year, which dosent help either.
In a warmer climate, with a more consistent drive pattern (Daily commuting and longer distance) it would'nt be a problim getting 55 - 60 mpg avagage in the Yaris hybrid with some modding and some hypermiling.
Here the Yaris was the best economy car I could get my hands on everything considered.
I think it's not possible to compare cars unless drivepattern and climate is about the same. Too many variables....

Quoting the Real Estate broker's mantra: "It's all about location, location, location"...and the..."weather, weather, weather."

Better milage
 

Had a tank with some longer trips, and milage surpassed 54 mpg. So getting closer to the 55 mpg target.
Summertires are going on within a week or two. Hope they are better than the winter ones. W'll have to see....

As far as modding goes, there no plans at the moment to add furter mods. The thermostat for the radiator opens at 90 deg.C, and I havent had the electric fan on yet, so before closing up more of the grill, I would like to find out when the fan kicks in.

For furter modding, I think I've got to look to the underbody and to the rear end. In the front the mirrors and the viper are also possible target for improvements. Just can't deside....

Summertires due for mounting om monday. FE hovering around the 53 - 54 MPG mark, at the moment.

Currently No. 14 om the hybrid list. In 2 months or so I'll climb the list with one or two positions once the bad tanks from the running in period is longer away in time. Biggest competitor will be the plug in Prius (PIP). But I'll start to breathe fuel wapors down the necks of those Insight drivers...

Wonder why so few hybrid owners keep a fuel log here? Would be so much more informative if more listed their fuelings here.

Car still drive like a dream.

Not shure what mod to do next. Still waiting for the summer tires to go on and break in, and some warmer wheater, so I can see how engine temps and fan behave in warmer conditions. Dont dare to block more grill before that....

Underside of car has to be looked at monday when tires get changed, and the car is on the garage lift.

Good job! I saw your rates climb. Won't be long before you have the Devil on your tail (instead of just ahead) :)
Will try to make it hard though ;)

I shall do my very best... :)
But due to work my drive pattern are very different from month to month. Some times lots of small trips, some time longer trips. Together with living in a cooler climate, it makes it more difficult.

Summer tires
 

To my big surpirse the factory mounted summer tires for the Yaris turned out to be Dunlop Sp sport fastresponce in 175/65 R15.

As it is an ECO car with good milage as a selling point, I was surprised to see those and not for instance Ecopias or Energysavers from Michelin, og Conto ECO contacts etc..

Does anybody know of the Dunlop's roling resistance and ECO capabilities?

As far as I can find it only listed as "moderate" in test with regards to better milage?

Otherwise seems to get very good reviews...

Well - gotta wear them out before getting some good LLR tires. Shure can't pay to change before they are worn out.

Starting with 3 Bar / 44,5 PSI and I'll see how they fare FE wise... Hope they are better than the Kleber wintertires that are on on the shelf at the dealers depo.

Well, I use to track my mpg, but once I exceeded 103 mpg I decided whats the point.

The longer the trip the better the mpg. I use to commute anywhere from 43-300 miles a day. I use to drive 150 miles twice a day. Do that with no ac and around 60mph and you just watch the mpg rack up. I also use to buy gas in the county vs city which had less ethanol and more mpg.

Cant help you with tires, Im sold on traction vs mpg. I rather have to slow down to merge into traffic vs speed up. :eek:

Summer finally came here in may and milage has improved steadely with rising temps. I've had a lot of driving lately with some longer trips on country main roads, and it shows.
Last tank gave 4.19 liter to a 100 km's.
Long way to get to the 4.0 L to a 100 km goal, and it will not happen on theese tires. Simply too much rolling resistance.
I added more presure to the front, and that helped at bit. I'm now running 3.2 bar front, and 3.0 bar rear.
Hoping for a long warm summer.
As of today 90 day FE avarage is at 53.99 Mpg, so hopefully I'll be able to break 25 km/liter og 58.8 mpg a lest a tankfull once in a while.

Nice work. Keep at it and I'd bet you'll break 60 mpg this summer yet.

The car looks great, I bet you can get more mpg's out of it

I don't think Ill brek the 60 mpg ine this summer. Mostly becauce of the silly tires the delivered with the car.
Also I live in a relative cold climate, and this car likes it warm. Summer peak temps has been reached, and from here on temps will start to decline, and milage with it.

The car likes warm starts. With ambient temps close to 30 deg. C, warm up time is almost none, as the hybrid drive kiks in with coolant temps at 40 deg. C or above.
Also the Yaris Hybris / Prius C lacks the better areo design of the back that the Prius has, which means that wind resistance is bigger, thus lower milage.

The car has a lot of potential though. What could be done was some short of Kamback or rear top spoiler, smaller side mirros - as those on the Yaris are HUGE - and a bellypan, as Toyota didnt make that to keep price down. Tires with lower rolling resistance will give at leat 1 mpg if not more.

No time at present to make mods, but as I plan to keep the car for at leat 8 year, there be plenty of time.

One other thing could be in play. I might have underestimates the break in milage of the car. I guessed it to be areoud 3.000 miles, but as mpg numbers has continues to climb at the car nears 7.000 miles, I suspect that the break in could be as long as 5.000 miles.

In my experience, it takes ~10,000 miles to break in a car. With the engine always turning off in a hybrid, that could take quite a bit longer :turtle:

Why not update your yaris to plug-in hybrid?