MPG query

Jim79

i have a 08 1.4 D-4D yaris. the electronic readout on the dashboard says i am getting 64-70 MPG but in reality i get about 53-55 MPG.

Is this typical or should i investigate further?

Senna

Jim79 wrote: »

i have a 08 1.4 D-4D yaris. the electronic readout on the dashboard says i am getting 64-70 MPG but in reality i get about 53-55 MPG.

Is this typical or should i investigate further?

Can you reset it? Reset it when you fill up and compare what it reads when you top up and work out your real mpg.
Computer readout will always be above true mpg, especially with city driving where you are sitting in traffic and not reading any fuel use.

savagethegoat

it sounds like he already did that

Senna

savagethegoat wrote: »

it sounds like he already did that

It was the reseting mpg calculator first part I was getting at.

Jim79

yes i reset it.

the big issue for me is that the real MPG that i get is lower than what the manufacturer claims it should be most of my driving is 'extra urban'

Jmccoy1

If you've an iPhone download an app called Gas Cubby. It allows you to keep track of your fuel usage based on your fill ups and works out all the stats for you.

Del2005

Jim79 wrote: »

yes i reset it.

the big issue for me is that the real MPG that i get is lower than what the manufacturer claims it should be most of my driving is 'extra urban'

You can never match manufacturers MPG as they do it on a rolling road with low resistance tyres. Read recently a quote from a manufacturer rep about quoted MPG, basically they said it's impossible to get in real life it's only useful when comparing cars pre purchase.

Have a look on Honestjohn or Parkers where people post their MPG to see if you are getting similar.

pa990

Del2005 wrote: »

You can never match manufacturers MPG as they do it on a rolling road with low resistance tyres. Read recently a quote from a manufacturer rep about quoted MPG, basically they said it's impossible to get in real life it's only useful when comparing cars pre purchase.

Have a look on Honestjohn or Parkers where people post their MPG to see if you are getting similar.

+1

Official mpg figures are pie in the sky, just like official vw emission figures.

When a car is being tested for mpg, the manufacturer strips out non vital components such as alternaters etc !
They also run on super skinny low resistance tyres, and they tape up any gaps between panels.
The test is also done in lab like conditions.

Manufacturer quoted mpg figures are not realistically achievable in the real world.

*Kol*

pa990 wrote: »

+1

Official mpg figures are pie in the sky, just like official vw emission figures.

When a car is being tested for mpg, the manufacturer strips out non vital components such as alternaters etc !
They also run on super skinny low resistance tyres, and they tape up any gaps between panels.
The test is also done in lab like conditions.

Manufacturer quoted mpg figures are not realistically achievable in the real world.

Why would they tape up panel gaps when it's done on a rolling road?

savagethegoat

Senna wrote: »

It was the reseting mpg calculator first part I was getting at.

that's not what he's asking about...his actual consumption is below the manufacturers figures and he's asking if that's normal. (it is)

vandriver

My Citroen readout gives a 20% higher fuel consumption figure than reality.

Del2005

*Kol* wrote: »

Why would they tape up panel gaps when it's done on a rolling road?

They used to do the MPG test on the road but discovered that doing it on a rolling road gave better figures, so they claim high MPG and since that correlates with reduced CO2 the regulators let them do it so it looks like vehicles produce less pollution. Greener cars without actually reducing fuel consumption!

pa990

*Kol* wrote: »

Why would they tape up panel gaps when it's done on a rolling road?

that was an older way of doing it, see below.

Del2005 wrote: »

They used to do the MPG test on the road but discovered that doing it on a rolling road gave better figures, so they claim high MPG and since that correlates with reduced CO2 the regulators let them do it so it looks like vehicles produce less pollution. Greener cars without actually reducing fuel consumption!

what i'm getting at , is that car manufactures will skew the test conditions to get the results that they want.

i'll try and find a link /vid about how they cheat at the tests.

Its a bit like CO2 levels, one of the ways that was reduced was by introducing start/stop technology. I dont like that an d its the first thing i switch off as soon as the car is moving. I dont think a diesel should be stopping and starting constantly, its just gonna add more wear and tear to the starter motor, and puts more pressure on the electrical system (as headlights, a/c, atc are still running when the engine is off)

pa990

here you go

http://www.dailymail.co.uk/news/article-3250524/New-fuel-hits-driver-Millions-motorists-cheated-hundreds-pounds-car-makers-overstating-efficiency.html

Industry insiders have told The Mail on Sunday that car-makers in Germany give examiners a specially prepared pre-production model in a scam known as ‘the Golden Car’. In other underhand tricks:

Cars are stripped of excess weight – including wipers and mirrors – for fuel efficiency tests.

Doors are taped up to reduce drag and tyres are pumped up to minimise friction with the road surface.

pa990

and.

http://www.theguardian.com/environment/2013/mar/14/car-manufacturers-manipulating-fuel-efficiency-tests

pa990

its nothing new, it has been going on since the 1970's

colm_mcm

Isn't the issue here that the trip computer is giving the wrong figure, did I read that right?

Jim79

colm_mcm wrote: »

Isn't the issue here that the trip computer is giving the wrong figure, did I read that right?

When i bought the car the dealer made a BIG deal about how great the MPG is on this car. The main issue that the car does not deliver the figures that the manufacturer states, the dealer said and the car readout says.

So i just want to make sure that the car is not burning excessive fuel & that has been answered by you guys to my satisfaction. thanks for all contributions.

John T Carroll

Jim79 wrote: »

i have a 08 1.4 D-4D yaris. the electronic readout on the dashboard says i am getting 64-70 MPG but in reality i get about 53-55 MPG.

Is this typical or should i investigate further?

On the 16+ year old VW thats in my family since new, there are three read outs, "instant" MPG that goes up and down like a yo yo, interestingly, but pretty uselessly, while going down hill it will read a max of 200 MPG but if you take your leg off the accelerator and as long as the RPM are above 1500 RPM, there is no fuel injected and a row of --- will appear in the display. The second read out is for a trip and if the engine is off for less than 2 hrs it will resume recording, if stopped for > 2 hrs it will reset, if you are sitting in traffic with the engine running you will see the average MPG falling as it appears to be taking the fuel consumed into account. The third and quite useful mode is that it will run for 100 hrs and then will reset, in this time depending on driving habits you may cover around 3000 to 3500 miles and on a few occasions, I have reset it, filled up and then say 90 or so hrs later have filled up again and compared the numbers and surprisingly they havnt been more than 10% optimistic, it also gives the average speed and the distance covered over the elapsed time. I have never filled up between trips so I cant comment on its accuracy in this mode.