What Mpg Does Your Computer Say?

[HowardL]

This may have been discussed before...mine says 44.1mpg

I doubt it's that accurate though.

[Cherry Red Pocket Rocket]

It should be accurate or why else have it? If you remained at that speed in the selected gear you would have gotten 44.1mpg. Mine said 99 something the other night but that was only briefly. I tend not to pay much attention to it as it is changing constantly and would have a nasty accident if I did. Have a go on the motorway and see what it says. You should get at least 40mpg out of a Yaris. I hope!

[smyffalis]

mine is at 41.3mpg today, hopefully itll be up. an idea is to take note of the date, cost, amount of litres and milage every time that you fill up and make a spreadsheet out of it.

gives you a far more accurate reading. 47.6mpg for me, and my auntie was 53mpg :o

[Bos]

This may have been discussed before...mine says 44.1mpg

I doubt it's that accurate though.

At the moment my 1.3 is indicating 53.4 mpg

[HowardL]

mine is at 41.3mpg today, hopefully itll be up. an idea is to take note of the date, cost, amount of litres and milage every time that you fill up and make a spreadsheet out of it.

gives you a far more accurate reading. 47.6mpg for me, and my auntie was 53mpg :o

Yes, I have done that before but cant remember the figure, but it was in upper 40's.

I must do it again(if I can remember to jot down the figures every trip to the garage )

[Cherry Red Pocket Rocket]

A much easier thing to do, in my opinion, would be to simply fill her up with fuel and then use the trip computer to record how many miles you do on a full tank. Then you can work out roughly how much you're getting out of a gallon.

[smyffalis]

taking cost and litres works out how much money you spend in total, how many litres/gallons used in total, and you can then work out that it is about 8-9p per mile!

once you really start taking a note of everything, you get used to it! got my dad into it aswell

[HowardL]

A much easier thing to do, in my opinion, would be to simply fill her up with fuel and then use the trip computer to record how many miles you do on a full tank. Then you can work out roughly how much you're getting out of a gallon.

It's much more accurate if it's done over a few weeks.

Fill the tank to full set the trip to zero then log how many litres you use over the weeks then fill up to full again and add it all up.

[Cherry Red Pocket Rocket]

Yeah, something like that. I bought a Yaris because they're safe, doddle to drive, maneuver, park, cheap insurance, sip fuel, cute and can be very quick!

[Shappers]

and can be very quick!

Compared to what...?

[Cherry Red Pocket Rocket]

Compared to my old Honda! Which stands for Hold On Not Done Accelerating, which was so true.

[Yaris SR Kid]

Mine is saying 35 at the moment which is pretty dam good, usually around 29!

[T V O R]

My computer says NO...

[Mat-O]

35 for me. can't really keep it above that. I tried keeping it to 40 once, but I struggled, plus it bored me greatly, so it's normally around 35 now that I haven't reset it for 2 months odd. It's sometimes higher sometimes lower if I do it per tank.

Note that that's with V-Power.

[cbzcbz]

My Yaris is doing around 36 mpg for me on 95 Ron, and 37.5 mpg a few weeks ago on 97 Ron. Which is not bad for town driving :)

[Karma Supra]

Usually about 19 lol

[Guest]

2008 1.3 Sr....41.7MPG on the screen, calculated actual 40.6

[Shappers]

Reset mine the other day to do a round trip of 200 miles... by the end the computer was reading 65.8 - the best i've had by far out of the yaris.

Around town I average 38 - 42 depending on driving style...

[rallybunny]

Around 38 on my TS, using Vpower. I don't really try to be careful though.

[eiriksmil]

I had 5 litres pr. 100 km last week on the m-way. I nearly hit a 100 mph and was cruising at about 70-80. Doubt they're very accurate :D

[oldun]

It should be accurate or why else have it? If you remained at that speed in the selected gear you would have gotten 44.1mpg. Mine said 99 something the other night but that was only briefly. I tend not to pay much attention to it as it is changing constantly and would have a nasty accident if I did. Have a go on the motorway and see what it says. You should get at least 40mpg out of a Yaris. I hope!

Re accuracy - speedometers are not very accurate (up to 10% error at 30 mph I believe) and the fuel measuring device is probably even less accurate so overall the computer offers, at best, a rough guide to fuel consumption.

There are two modes of operation for mpg, local mpg and average mpg. The local mpg will read 99.9 mpg when th car is coasting as no fuel is being used, hence infinite mpg. When accelerating from rest uphill it will show and unbelievably low mpg, as you might expect.

When using average mpg (surely th sensible one to use) my 2009 D4D shows between 45 mpg in town and 56 mpg when cruising at about 65 mph on an open road. I have kept a record of all fuel used since it was bought and it has returned about 52 mpg.

[Stoford Yaris]

It will not be very accurate due to the technology Toyota employs in the "computers" in cheaper variants like the Yaris. The "computer" is essentially a glorified calculator that tracks registered speed (itself not accurate as it comes from the speedo) and relates that to a table of fuel consumption rates. Done every second this gives a THEORETICAL rate of fuel consumption - my wife's Yaris usually shows 42mpg but consumes usually needs a 34 litre (8 gallons approx) fill up every 280 miles - nearer 35mpg.

It's the same logic with the "miles on tank" countdown. This is reset when you refuel and uses the theoretical consumption to calculate range. It then counts down mile for mile.

Toyota is by no means unusual in the way these things work. At the lower end of the car market it's pretty much the norm, to my knowledge only Honda fit a more sophisticated "computer" in cheaper cars and even that is not really an accurate device.

[carlowlad]

A few years ago i was done for speeding in another car. I was holding my car at 100 mph and when he caught me the copper showed me his radar gun and it showed exactly 100 mph on the display. Now, i know cars are different from each other in terms of how they calculate speed etc but i wouldn't say the speedos are too far out. That said, i'll check going into work this evening and see how much out mine is. I use a scangauge and have it reading the same speed as the cars speedo, whose accuracy is, of course, debatable. It is saying i get 3L/100k per tank but in reality i am getting 3.5L/100k after i measure the old way. So something is amiss there.

[Guest]

43.1 on the average mileage read out, actual calculated of 41.1 in my '08 1.3 SR. its definatley getting better as time goes on, just under 5k at the momment, hoping there is still some improvemnt to come. Im doing nearly a thousand miles next week, so i should get some back to back full tanks for comparison

On the subject of the speedo beeing wildly out, at an indictaed 70 on the dash, the built in Tom Tom says im doing 65, 30 on the Tom Tom is 33 on the dash.

[carlowlad]

On the subject of the speedo beeing wildly out, at an indictaed 70 on the dash, the built in Tom Tom says im doing 65, 30 on the Tom Tom is 33 on the dash.

So it would seem the cops radar guns are "out" by the same amount. Could it be that signboards on the road are also similarly measured? I've come across this subject before but never got around to sorting it out. I'd say the gps is fairly accurate so that should be what we go by. Unless we come across an extremely cross copper and he does me for one or two above the speed limit! Will he listen to my story about the GPS giving me a true speed readout??

ollie