Yaris 1.4D-4D Fuel Consumption

[Alchy]

Hi everyone

Got a Yaris 59 plate (Jan 2010) with the 1.4D-4D engine and 6 speed gear box

I've picked up the car form a Toyota dealer about a week ago with 8,500 miles onboard

I was hoping to get at least 70 - 75mpg extraurban but the reality is i can hardly get 63 -64. This is mainly motorway driving, not pushing above 65mph, tyre pressure checked and all the rest...

I have contacted the dealer and booked in for a check but I would also like to ask for your opinion: is 70 -75mpg extraurban just a dream or is indeed achievable with proper engine adjustment?

Many thanks!

Alchy

[Madasafish]

I have the previous model diesle and get about 63mpg on long runs.

A lot depends on: engine run in? 10k miles at least I would say. Thrash it hard for a couple of weeks - Italian tune up.

Driving style..

Speed.

Choice of fuel. Use supermarket? Or Shell?

Frankly you could get over 70mpg - and I could too- by driving at a constant 60mph with zero braking and acceleration, no headwinds and no hills.

If you can answer all the above points... then we can have a discussion. until then , far too many variables..

Oh and how did you check fuel consumption? Computer? Can be 10% out..

And over how many miles?

[Alchy]

I have the previous model diesle and get about 63mpg on long runs.

A lot depends on: engine run in? 10k miles at least I would say. Thrash it hard for a couple of weeks - Italian tune up.

Driving style..

Speed.

Choice of fuel. Use supermarket? Or Shell?

Frankly you could get over 70mpg - and I could too- by driving at a constant 60mph with zero braking and acceleration, no headwinds and no hills.

If you can answer all the above points... then we can have a discussion. until then , far too many variables..

Oh and how did you check fuel consumption? Computer? Can be 10% out..

And over how many miles?

I have done over 1,000 miles (taken it to Netherlands over the weekend) so far and checked the average "old school" style - fill up reset counter, drive for 300 miles, fill up again then do the maths. I've used only Vpower from Shell and normal diesel from Texaco

I shall follow your advice and be an Italian for few weeks and see what happens

[carlowlad]

Italian tune ups should only be done about once or twice per tank. If you do it all the time then you will just use more fuel all the time.

Your car is quite new and still needs running in. Also, once you go above 60 mph you will see a big increase in fuel consumption no matter what you do. And now that the weather is getting colder you will see it drop even more.

I see you have the six speed. Oh boy would i love that gearbox in my 2004 yaris! Whats the rpm in 6th like at 60 mph?

[stevecrvn]

I am getting about 64 mpg on 2005 yaris D4D WITH 28,000 Oo the clock which is used mostly on motorways which I try yo keep to 65-70 mph .

To be looking for 70 mpg plus is a bit of a long shot as these figures by Toyota would have been achieved under test conditions

Steve

[Madasafish]

I am getting about 64 mpg on 2005 yaris D4D WITH 28,000 Oo the clock which is used mostly on motorways which I try yo keep to 65-70 mph .

To be looking for 70 mpg plus is a bit of a long shot as these figures by Toyota would have been achieved under test conditions

Steve

Test conditions = rolling road afaik

"checked the average "old school" style - fill up reset counter, drive for 300 miles, fill up again then do the maths. "

Based on my experience, filling up varies by between 1-3 litres depending on any slope on the forecourt...

[Alchy]

Italian tune ups should only be done about once or twice per tank. If you do it all the time then you will just use more fuel all the time.

Your car is quite new and still needs running in. Also, once you go above 60 mph you will see a big increase in fuel consumption no matter what you do. And now that the weather is getting colder you will see it drop even more.

I see you have the six speed. Oh boy would i love that gearbox in my 2004 yaris! Whats the rpm in 6th like at 60 mph?

Is good, is about 1700 / min, i get 2200 at 80 and can go easy above that, obviously the mpg are less...

I agree that it still needs grinding, the official figure for extraurban is 78mpg i was expecting however at least 70...anyways, we shall see how it goes

[Alchy]

I am getting about 64 mpg on 2005 yaris D4D WITH 28,000 Oo the clock which is used mostly on motorways which I try yo keep to 65-70 mph .

To be looking for 70 mpg plus is a bit of a long shot as these figures by Toyota would have been achieved under test conditions

Steve

Does your car have a 6 gear speed box?

[Alchy]

I am getting about 64 mpg on 2005 yaris D4D WITH 28,000 Oo the clock which is used mostly on motorways which I try yo keep to 65-70 mph .

To be looking for 70 mpg plus is a bit of a long shot as these figures by Toyota would have been achieved under test conditions

Steve

Test conditions = rolling road afaik

"checked the average "old school" style - fill up reset counter, drive for 300 miles, fill up again then do the maths. "

Based on my experience, filling up varies by between 1-3 litres depending on any slope on the forecourt...

Filled up to the top (i could se the fluid inside) but you are right, this is one variable i can't exclude

[Cyker]

Just an aside - V-Power diesel will give you less mpg.

I've gotten 70+ mpg on long motorway runs.

[stevecrvn]

I am getting about 64 mpg on 2005 yaris D4D WITH 28,000 Oo the clock which is used mostly on motorways which I try yo keep to 65-70 mph .

To be looking for 70 mpg plus is a bit of a long shot as these figures by Toyota would have been achieved under test conditions

Steve

Does your car have a 6 gear speed box?

No only 5

[Alchy]

I am getting about 64 mpg on 2005 yaris D4D WITH 28,000 Oo the clock which is used mostly on motorways which I try yo keep to 65-70 mph .

To be looking for 70 mpg plus is a bit of a long shot as these figures by Toyota would have been achieved under test conditions

Steve

Does your car have a 6 gear speed box?

No only 5

Well, this is my problem, i have 6 and I was expecting more than 65 for a journey at about the same speed

Had a chat with the technician from Toyota today, had the counter reset and been advised to use regular diesel not Vpower (thanks also @Cyker for the same advice although I don't understand why... ) and lower(!)the tyre pressure to 32 on front and 30 back (i had 38/35 as per booklet) - again I don't get it - the guy told me that he only holds anecdotal evidence that lower tyre pressure would increase the mpg...

Anyway, I shall follow his / your advice and feed back in a week or so

[grin factor]

Official fuel figures are always optomistic and of all the cars I've had have never got anywhere near them.

[Cyker]

The reason V-Power actually gives less MPG is because there is less fuel-per-litre; There is a lot more extra stuff (mainly cleaners and things), and also the GTL synthetic diesel has a slightly lower energy-per-mass than mineral diesel.

The good thing about V-Power is that it burns more completely and cleanly and you do feel an increase in power as the revs climb.

However, there is a slight torque loss, and to get high mpg you want low-revs and high torque, so it doesn't help there...

The D4D engine has good low-end torque for such a small engine and you can easily drive in 4th gear most of the time.

5th is a bit marginal unless the road is very flat, at least until you get to 36mph+.

With V-Power, the engine struggles more at lower revs to supply the torque, but is more free revving so I find I have to shift a bit later to avoid stressing the engine..

However, the thing about tyres is just plain WRONG!!

Having tyre pressures on the low side, esp. at motorway speeds, will just wear them out faster and you'll loose a lot of energy to the increased drag.

Lower tyre pressures = Higher low-speed grip, higher tyre wear, more drag; The increased drag adds up to worse fuel consumption as there is a lot more rolling resistance

High tyre pressures = Lower low-speed grip, less drag, and lower fuel consumption as the rolling resistance is less (You do notice you can roll in-gear longer on a higher-pressure tyre).

I run mine at 40/35 and I reckon that's partly why I've been able to get pretty high mpgs. The other big win is looking ahead and anticipation; I can often cruise and coast (in-gear!) through several sets of traffic lights without stopping when I'm on form while other people are speeding off and braking at every light and that really does save a lot of fuel.

There is a difference of opinion here as to whether having high tyre pressures is safe; There is no danger of them exploding or something (Well, assuming the tyre doesn't have a weak spot like a cut), but the lower grip is noticeable, esp. in the wet.

The other option is to buy low-friction tyres, which gives similar effects, although Michellin claim theirs has better wet grip.

[carlowlad]

I agree with Cyker above too. Higher tyre pressure will increase mpg. Lower pressure will just wear your tyres out quicker.

The grip thing is an onging debate and i doubt there will ever be (publicly available) scientific proof of it. I've run mine at 44 psi since i got it at the end of 2008. Grips like a leech. I even drove through snow last winter and went up hills where others were skidding everywhere. I will say though, that higher pressures again just lead to the tyres bouncing due to the shocks not being able to keep up with the bumps. A savage set of rally shocks would, no doubt, help things on that front! I must also point out that my tyres are wearing evenly and slowly.

I made up a pumped engine heater last year and it gives me a nice warm engine after two hours heating with a 1KW heater. I only use it when temps get down to below 10c as there is no point above that really. I made a gearbox heater too and that was sweet. Gearchange was smooth from the start, no matter how cold it was outside! But i had to scrap that due to the heater falling off the gearbox all the time from vibrations. Theres only so many times i can open the undertray on that thing!

I wouldn't, of course, do this to a 2010 car but if there was a heater available for it i would certainly look into getting one professionally installed. Small diesels take forever to warm up.

[Madasafish]

Last year I changed gearbox oil to fully synthetic.. and found gearchange - which was already pretty good- did not suffer at all last winter.. (Coldest night -19C).

|If gearchange is an issue try Castrol Manual SMX-S Gear Oil - (Halfords).. It improves change greatly..

Engine heater? I should bother but can't be...

[RS4]

Driving carefully in my 2005 Yaris D4D I averaged 79.6 mpg over a 5 month, mainly winter, period (i.e. December to May). I logged the miles from my odemeter and the litres from my diesel reciepts, so in 10,767 miles I used 615.27 litres of fuel. My commute is 580 motorway miles per week and I tried different things to improve the mpg. Such as: fully synthetic 0W-40 engine oil, fully synthetic 75W-90 gearbox oil, fuel additives, different fuels and always checked/adjusted the cold tyre pressures every week with an accurate dial type pressure gauge. Keeping the motorway speeds down to between 56 to 60 mph makes a massive improvement as does smooth acceleration, anticipating traffic lights etc.... So, I think moderating the use of right foot is the key to high mpg figures.

[carlowlad]

Driving carefully in my 2005 Yaris D4D I averaged 79.6 mpg over a 5 month, mainly winter, period (i.e. December to May). I logged the miles from my odemeter and the litres from my diesel reciepts, so in 10,767 miles I used 615.27 litres of fuel. My commute is 580 motorway miles per week and I tried different things to improve the mpg. Such as: fully synthetic 0W-40 engine oil, fully synthetic 75W-90 gearbox oil, fuel additives, different fuels and always checked/adjusted the cold tyre pressures every week with an accurate dial type pressure gauge. Keeping the motorway speeds down to between 56 to 60 mph makes a massive improvement as does smooth acceleration, anticipating traffic lights etc.... So, I think moderating the use of right foot is the key to high mpg figures.

+1

Thats some good mpg. Do you mind if i ask what pressure your tyres are at? And is that oil type recommended in your manual? Mine says 5W-30 minimum but it's a year older than yours so there may be a difference.

[RS4]

Driving carefully in my 2005 Yaris D4D I averaged 79.6 mpg over a 5 month, mainly winter, period (i.e. December to May). I logged the miles from my odemeter and the litres from my diesel reciepts, so in 10,767 miles I used 615.27 litres of fuel. My commute is 580 motorway miles per week and I tried different things to improve the mpg. Such as: fully synthetic 0W-40 engine oil, fully synthetic 75W-90 gearbox oil, fuel additives, different fuels and always checked/adjusted the cold tyre pressures every week with an accurate dial type pressure gauge. Keeping the motorway speeds down to between 56 to 60 mph makes a massive improvement as does smooth acceleration, anticipating traffic lights etc.... So, I think moderating the use of right foot is the key to high mpg figures.

+1

Thats some good mpg. Do you mind if i ask what pressure your tyres are at? And is that oil type recommended in your manual? Mine says 5W-30 minimum but it's a year older than yours so there may be a difference.

Tyre pressures as per the owners manual (can't remember the exact figures as I changed the car in July for an 07 Yaris D4D), checked with a good quality dial type gauge while cold. Also note the car had a full set of Vredestein Snowtrac 3 winter tyres fitted from October to March.

From memory, I think the owners manual stated 5W-40 grade engine oil. I used Mobil 1 0W-40 as it is based on a 5W-40 grade, with additives, to lower the viscosity at the lower end of the temperature range. The viscosities converge at the upper end of the temperature spec.

[Alchy]

Driving carefully in my 2005 Yaris D4D I averaged 79.6 mpg over a 5 month, mainly winter, period (i.e. December to May). I logged the miles from my odemeter and the litres from my diesel reciepts, so in 10,767 miles I used 615.27 litres of fuel. My commute is 580 motorway miles per week and I tried different things to improve the mpg. Such as: fully synthetic 0W-40 engine oil, fully synthetic 75W-90 gearbox oil, fuel additives, different fuels and always checked/adjusted the cold tyre pressures every week with an accurate dial type pressure gauge. Keeping the motorway speeds down to between 56 to 60 mph makes a massive improvement as does smooth acceleration, anticipating traffic lights etc.... So, I think moderating the use of right foot is the key to high mpg figures.

+1

Thats some good mpg. Do you mind if i ask what pressure your tyres are at? And is that oil type recommended in your manual? Mine says 5W-30 minimum but it's a year older than yours so there may be a difference.

Tyre pressures as per the owners manual (can't remember the exact figures as I changed the car in July for an 07 Yaris D4D), checked with a good quality dial type gauge while cold. Also note the car had a full set of Vredestein Snowtrac 3 winter tyres fitted from October to March.

From memory, I think the owners manual stated 5W-40 grade engine oil. I used Mobil 1 0W-40 as it is based on a 5W-40 grade, with additives, to lower the viscosity at the lower end of the temperature range. The viscosities converge at the upper end of the temperature spec.

Hi everyone

Happy to report back after a some time of testing

Average between 66 and 73 mpg using different types of fuel, different tyre pressures and different driving syles etc

The best average i had was with Shell Fuelsave (obviously ), tyre pressure 40 on front and 35 on back, speed around 50 - 60mph (mainly dual carrigeways and A roads). I've used more the 5th instead of the 6th gear and as RS4 was saying, anticipation and acceleration behaviour is very important.

66mph is not bad if you consider that i've done mainly motorway, high speeds (where the 6th gear comes in handy) on texaco diesel.

Overall i am happy with the outcome and taking into account that i've got only 10,050mile on board I am hoping that fuel consumption will only improve from now on.

Many thanks for all your contributions!

[carlowlad]

Nothing wrong with that at all! Is it the 1nd-tv engine? I wonger if the gearbox would fit an older yaris........... :D

[Alchy]

Nothing wrong with that at all! Is it the 1nd-tv engine? I wonger if the gearbox would fit an older yaris........... :D

Not familiar with '1nd-tv engine', remember I am a newbie :) so you may need to spell it for me...

[carlowlad]

Nothing wrong with that at all! Is it the 1nd-tv engine? I wonger if the gearbox would fit an older yaris........... :D

Not familiar with '1nd-tv engine', remember I am a newbie :) so you may need to spell it for me...

It's the diesel yaris engine. I believe it is in all of them including the new ones. I figured if it was the same engine then i could retrofit a 6 speed gearbox into mine, should i ever need to. heh!

[Cotswold gardener]

Driving carefully in my 2005 Yaris D4D I averaged 79.6 mpg over a 5 month, mainly winter, period (i.e. December to May). I logged the miles from my odemeter and the litres from my diesel reciepts, so in 10,767 miles I used 615.27 litres of fuel. My commute is 580 motorway miles per week and I tried different things to improve the mpg. Such as: fully synthetic 0W-40 engine oil, fully synthetic 75W-90 gearbox oil, fuel additives, different fuels and always checked/adjusted the cold tyre pressures every week with an accurate dial type pressure gauge. Keeping the motorway speeds down to between 56 to 60 mph makes a massive improvement as does smooth acceleration, anticipating traffic lights etc.... So, I think moderating the use of right foot is the key to high mpg figures.

+1

Thats some good mpg. Do you mind if i ask what pressure your tyres are at? And is that oil type recommended in your manual? Mine says 5W-30 minimum but it's a year older than yours so there may be a difference.

Tyre pressures as per the owners manual (can't remember the exact figures as I changed the car in July for an 07 Yaris D4D), checked with a good quality dial type gauge while cold. Also note the car had a full set of Vredestein Snowtrac 3 winter tyres fitted from October to March.

From memory, I think the owners manual stated 5W-40 grade engine oil. I used Mobil 1 0W-40 as it is based on a 5W-40 grade, with additives, to lower the viscosity at the lower end of the temperature range. The viscosities converge at the upper end of the temperature spec.

Hi everyone

Happy to report back after a some time of testing

Average between 66 and 73 mpg using different types of fuel, different tyre pressures and different driving syles etc

The best average i had was with Shell Fuelsave (obviously ), tyre pressure 40 on front and 35 on back, speed around 50 - 60mph (mainly dual carrigeways and A roads). I've used more the 5th instead of the 6th gear and as RS4 was saying, anticipation and acceleration behaviour is very important.

66mph is not bad if you consider that i've done mainly motorway, high speeds (where the 6th gear comes in handy) on texaco diesel.

Overall i am happy with the outcome and taking into account that i've got only 10,050mile on board I am hoping that fuel consumption will only improve from now on.

Many thanks for all your contributions!

We are averaging 67 MPG in our 03 Yaris GS D-4D only driving on country roads, A roads and motorways. Very Pleased with that.