Is trip computer acurate?

[brisbanecamry]

G'day all,

I have an 03 Ateva 2.4. . . .just a bulk standard one and I try and drive it pretty light to save fuel.

The fuel consumption meter/computer thingo which I have not reset for 6months always shows my consumption and being either 8.5L or 8.6L /100km. The consumption level I am happy with but I heard someone say once that these computers are only very approximate.

I haven't gotten around to measuring with any level of acuracy distance vs liters to refile the tank but I do generally get around or a bit over 600km per tank so am guessing tghe computer is in the right ball park....

So how acurate do people think these things are? and does anyone know how the 'range' is calculated? is it done based on the average fuel consumption over the life of the car or based on the last few minutes of driving????

Cheers

[perthcamry]

Welcome Brisbane Camry :P Good to see the you in Camry land :D

[Terry]

well i reckon the trip computer is fairly accurate...

not 100%...but its close enough...

for me it tells me about 14L/100km and i did my own calculations and that is about right ;)

the range is calculated on the basis of your average fuel consumption, that is the overall average consumption, not the instantanous one.

the car knows how much petrol is left in the tank and calculates accordingly.

[bigdenis]

I generally find that the displayed value is about 5 - 7% off in my car. That is, it registers, for example, that I've used 46L, but when I fill up, I can only manage 43L.

[leasaunce]

geezee, you guys are pretty high tech!!! B)

damn if only my camry have that gadget :(

[u54mot]

Yep, the litres used is always lower by about 10%(well just under) then what it says on the trip computer. ie if it the trip meter says you've used 60L it really is only about 54L used.

Also the range on the trip computer(on mine anyway), is calculated with 60 litres in the tank, and not the actual 70 Litres that is really in the tank. so the trip meter will read LOW once it reaches 60 Litres, and the orange indicator will light up shortly after that. (which is the common practice, as you should not allow the petrol level reach too low, as stated in the owner's manual).

With the debate over the RON level to use. There are differences in the fuel efficiency. I usually stick to 95 RON, but pour 98 every now and then, only if i am at BP or Shell, just because i don't wanna be rorted that extra 1/2cents by Caltex and Mobil(haha). I have tried all the below(except synergy 6000) and would usually stick to petrol @ either BP or Shell. Caltex fuels seem to be lower in efficiency(Mobil; just don't seem to be anywhere near one when i pour petrol)

The Fuels currently available on the market are(other than unleaded):

Company - Type - RON (Price premium over unleaded)

Shell - Unleaded 95 -95 (+6c)

Shell - Optimax -98 (+10c)

BP - Premium -95 (+6c)

BP - Ultimate -98 (+9c)

Mobil - Synergy 6000 -95 (Don't know)

Mobil - Synergy 8000 -98 (+11c)

Caltex - Vortex 95 -95 (+7c)

Caltex - Vortex 98 -98 (+11c)

About my efficiency, i don't think you'd wanna compare mine to yours, as i have 235/45R17 which is wider tread than the normal, and also larger in diameter, hence will use more petrol just because of those two factors. Pressures are kept at 34PSI.

From nearly 20000km of driving(from new) the overall average is 13.67L/100Km. The minimum i have achieved is 12L/100km(only half a tank)in city driving, and 11.2L/100Km in country driving.

But all those numbers are all dependent on the way you drive.

Thats all for now.

[Cosmo]

im gonna have to say its not quite accurate, with calculations you should be getting around 824km on one tank...though I assume that you don't entirely drain your fuel tank everytime :)

[Terry]

^

800km per tank, i wish i got something like that :o

how did you calculate it?

the way i do it, is fill the tank full, then using the odometer measure how many kilometres until my next fill up.

then fill the tank full again, and using the odometer measurement and also the amount of petrol you just put in, you measure the fuel consumption ;)

[Cosmo]

to calculate it from that L/100km reading you...

1) Divide 100 by the "L/100km" figure

2) Multiply this figure by the number of litres your fuel tank is...which is 70L in our case :)

[Terry]

yeah i know that

but thats using the trip computer score...

im saying, you should calculate the actual fuel consumption, without using the trip computer :P

since the accuracy of the trip computer isnt all that great sometimes...

1) Fill Full Tank

2) Reset Odometer

3) Drive until you need to refill tank again

4) At the service station, record the odometer reading

5) Fill tank full, record the number of litres you just put in.

6) Calculate using the number of litres divided by the number of kilometres just travelled, times 100.

7) then using this score, calculate how much you can run in a 70L tank, as shown in above post.

well thats the most accurate method i can come up with, and it works for me

[pingu]

guys, im geting like 450 K's per full tank. It's so frustrating.. Im on BP ultimate ron 98. How the hell did you get 800 K's? whats ur secret :P

[Cosmo]

Personally, I RARELY get over 500kms, so I'd also know how to get 800 :P

The lowest fuel consumption I've ever had in my Camry was 3.6L/100km... but that was for about half an hour :(

Edited November 1, 2005 by Cosmo

[vitagen]

Yep, the litres used is always lower by about 10%(well just under) then what it says on the trip computer. ie if it the trip meter says you've used 60L it really is only about 54L used.

Also the range on the trip computer(on mine anyway), is calculated with 60 litres in the tank, and not the actual 70 Litres that is really in the tank. so the trip meter will read LOW once it reaches 60 Litres, and the orange indicator will light up shortly after that. (which is the common practice, as you should not allow the petrol level reach too low, as stated in the owner's manual).

With the debate over the RON level to use. There are differences in the fuel efficiency. I usually stick to 95 RON, but pour 98 every now and then, only if i am at BP or Shell, just because i don't wanna be rorted that extra 1/2cents by Caltex and Mobil(haha). I have tried all the below(except synergy 6000) and would usually stick to petrol @ either BP or Shell. Caltex fuels seem to be lower in efficiency(Mobil; just don't seem to be anywhere near one when i pour petrol)

The Fuels currently available on the market are(other than unleaded):

Company - Type - RON (Price premium over unleaded)

Shell  - Unleaded 95    -95  (+6c)

Shell  - Optimax          -98  (+10c)

BP      - Premium          -95 (+6c)

BP      - Ultimate            -98 (+9c)

Mobil  - Synergy 6000  -95 (Don't know)

Mobil  - Synergy 8000  -98 (+11c)

Caltex - Vortex 95        -95 (+7c)

Caltex - Vortex 98        -98 (+11c)

About my efficiency, i don't think you'd wanna compare mine to yours, as i have 235/45R17 which is wider tread than the normal, and also larger in diameter, hence will use more petrol just because of those two factors. Pressures are kept at 34PSI.

From nearly 20000km of driving(from new) the overall average is 13.67L/100Km. The minimum i have achieved is 12L/100km(only half a tank)in city driving, and 11.2L/100Km in country driving.

But all those numbers are all dependent on the way you drive.

Thats all for now.

←

hey 34 PSI is really quite low for 17" low profile tyres

try inflating to about ~40 PSI u see ur fuel economy will improve :)

[perthcamry]

Hey Spordeano,

I was thinking about your fuel economy being so good, did the Fitch thing make much difference?

I have it in mine too now. B)

[spordeano]

Hey Spordeano,

I was thinking about your fuel economy being so good, did the Fitch thing make much difference?

I have it in mine too now. B)

←

Yeah I think it did, I've noticed the difference anyway, to me its worth the money :D