I did another trip on the weekend, of 400km, climate air on continuously and reasonably well loaded with 25% urban driving.  The trip computer said 6.1l/100km and the tank was 2/3 full by guage at 400km. Anyway on topping up the tank it took 32.8 l to fill I took my time and fuel was visible in the spout, anyway this equates to 8.2l/100km  .  Questions to experienced forum members.

1. Is the fuel consumption on the trip computer accurate? I reset after filling each time.
2. Is this a result of inconsistent filling? I have seen on these forums that the fuel tank seems to hold a lot more than the official 53l somewhere from 57-60l mentioned    Is 53l only to the first"click" of the nozzle.

Any suggestions to get a more accurate correlation between the computer and actual calculated value?

[Dazzler]

Hi Mick

I think the general consensus on here is only a couple of tenths difference between the trip PC and actual usage figures.

Sounds like you put heaps extra fuel in on the refill.

If you are not going to fill it to the brim before and after your test you need to fill it to the first click both times at the same pump...

Thanks. yeah what I thought as well, it's hard to consistently fill the tank, there is only one diesel pump and if someone else is waiting I feel  should be quick and it takes a fair bit of time to get those extra litres in.  Anyway the gauge said it was still 2/3 full even after 400 km had been covered.

[inmn]

I have now had my i30 cw auto diesel for nearly 2 months. We have filled it up 6 times, and have noticed a difference between when my wife fills it up (only to the 1st click) and when I do it (always get a few more litres in).

Over 4627km have used 283.53 litres of diesel, which is 6.13 l/100km or 16.32 km/l or 38.4 MPG (US Gallons). This is for 95% rural driving.

When my wife fills it to the 1st click the average is 5.6 l/100km, whereas when I fill it the average is closer to 6.3 l/100km.

So what really counts is not the individual tank figures, but total averages, this allows for the fact that the tank is not filled in a consistent way. I would think that the trip computer calculates fuel consumed divided by distance traveled. So if the tank is filled to the absolute brim, especially after it was filled only to the first click, the indicated fuel economy by the trip meter would be different to that calculated on filling up by how much extra fuel was added to the tank after the fist click.

[Dazzler]

When my wife fills it to the 1st click the average is 5.6 l/100km, whereas when I fill it the average is closer to 6.3 l/100km.

So what really counts is not the individual tank figures, but total averages, this allows for the fact that the tank is not filled in a consistent way. I would think that the trip computer calculates fuel consumed divided by distance traveled. So if the tank is filled to the absolute brim, especially after it was filled only to the first click, the indicated fuel economy by the trip meter would be different to that calculated on filling up by how much extra fuel was added to the tank after the fist click.

That is an interesting bit of feedback... probably doesn't align with my experience but I guess it is possible....My economy didn't seem to vary more than .1 LPH no matter how much fuel I put in (and I usually reset after each fill)

Did 560km on the weekend, climate air on, windy conditions and loaded up. I just filled up well beyond first click 38litres = 6.78l/100km computer saying 6.5/6.6.  Pretty happy with 41mpg in old money and not trying to drive for economy.  This probably represented 20/80 city/freeway

[Brew69]

After 8000kms i find my trip computer to be within .1 all the time. It still can't work out how far i get on a tank which i hoped it would by now. Still tells me i will only get 700kms out of a tank after re-filling even though the fuel economy which was saying in the low 5's is reset. I then go and get 1100kms out of the tank. BP Ultimate is the way to go if you can get it.

[Eiki]

Hi I have been driving a lot this weekend ca. 900 km an only on motorway...slight traffic.
I am careful not to  exeed the maximum speed around 120 km .h. and the fuelconsumtion after the weekend is amazing 3,4 ltr /100 km.
3 persons onboard
The car is 1,6 manual 115 hp  + chiptuning that makes the difference 

[agentr31]

3.4L/100km WOW!!! thats amazing!

[skalra63]

I find my trip computer is way out.

It usually says that I have been doing about 54.5-56 MPG but in actual fact, the calculations show that I get random amounts. Sometimes as low as 52...once as high as 57 MPG. It has only been similar a few times...I have had the car almost 6 months and fill the tank to the first click every week.

[agentr31]

try and be more consistent when you fill it... fill it to the very top!!!

[mtuckeruk]

Why not fill the tank when the fuel indicator light comes on. I find if I fill mine to the brim when the fuel light comes it takes 53 litres or very close.

Just goes to show how much extra you can get in above the 53 litres.

[skalra63]

I always use the same pump until it clicks.

[agentr31]

i do it untill i can see diesel! and only fill when the tank is empty! i dont worry about figuring out fuel consumption as such!

because i know its THAT GOOD!!!

[2i30s]

the fuel tank in an i30 is in the middle of the car so the filler neck is very long,i estimate around 6 to 8 liters could be in the filler neck alone.maybee more.    [2" tube at about 1.5 meters long]

[agentr31]

yer its a bit silly, but not a bad thing!

i think having such a long filler neck is what makes it foam so much!

[2i30s]

i don't have that problem, with petrol. 

[agentr31]

LOL winn!!!

[Lakes]

Ian, when i fill with normal diesel, i notice it foams a lot, but the pemium diesel does not foam much and is easy to fill.
i had the light come on fri night & filled up fast with caltex vortex diesel reasonably quick 55L not too much foam.
i notice diesel pumps a lot faster than unlead i have to fill up the work toyota every two or three days so can tell difference. the 2.7 Hiace goes about 350k on 55L in syd, the i30 1.6 CRDi goes about 1,100k on 55L in syd and the i30 more fun.

[agentr31]

yer i have noticed that! i have found up here, that the BP diesel foams the least! (im not being biased or anything)

then caltex vortex, and the worst is the shell normal diesel! thats like 99% foam i think!

[Opa_1]

yer i have noticed that! i have found up here, that the BP diesel foams the least! (im not being biased or anything)

then caltex vortex, and the worst is the shell normal diesel! thats like 99% foam i think!

Agree with you agent, BP diesel seems the easiest to fill to the brim so I expect, minimal foaming, Caltex is also pretty good but I can't generally get Vortex as not all the outlets provide it. Devenport in Tasmania had it but they waited until Dazzler SOLD his beloved Luna before installing it.. Sorry Darryl..

[Dazzler]

Yeah that was weird...The first time I went to fill the replacement car (my Hybrid) with unleaded i took a cursory glace at the diesel pump and then a second look when I saw it was now premium diesel (at the same price as regular diesel used to be...

I don't know if the Hybrid would perform better on premium Unleaded (But I'm not going to find out either while it is 20c per litre dearer in Devonport  )

I just did around 700 kms (trip away to Hobart for the weekend) and saw some really low figures (under 6.0) but eventually settled at 6.2 average (Trip PC is indicating over 900 from this tank) Considering it is an Auto (CVT) I am very happy..

[ozsnowman]

i do it untill i can see diesel! and only fill when the tank is empty!

Yep, that covers me too!

Filled up yesterday after 778km, Trip computer said 120km to empty, so there must have been a fair amount of fuel remaining in the tank. Anyway fill up was 52 litres! Trip computer said 6.3 l/100km actual would appear to be 6.7l/100km.  There car was very heavily loaded on all accasions with a fair amount of short running, so I'm pretty happy with the economy at this stage

[agentr31]

only another 4L left in my books!

[Joel]

My auto i30cw diesel has settled on about 7.8l/100km but I am happy with that, I have been keeping climate control on all the time and this is for driving to work through Melbourne peak hour (I live close to the city, so a lot of start/stop driving).

Am going to do a hwy trip this weekend, keen to see how it goes...

Interesting you should say that.  The fuel gauge was still above empty roughly half way between e and 1/4 , no fuel light either. Some on this forum claim it is possible to get 60l into the tank.  If the DTE is anywhere near accurate (still indicating 120km to go) there would have to be at least 7 l remaining in the tank.

Any comments on the accuracy of the fuel gauge? How much fuel is left when the fuel light comes on?

[Dazzler]

Any comments on the accuracy of the fuel gauge? How much fuel is left when the fuel light comes on?

The fuel gauge is like most other cars, the second half goes down quicker than the first.. From memory the fuel light comes on with about 105kms remaining according to the trip computer (for the diesel).

As discussed on here before, even when down to that level of fuel the DTE is still conservative and although the DTE stops counting down when it gets below 50kms remaining (goes to --) I believe a couple of brave souls have managed to get close to another 100 kms (making a total of almost 150 kms on the light)  

Edit: I am talking the Manual CRDi so one would expect the Auto to be a few Kms shy of those figures...

[Joel]

My auto i30cw diesel has settled on about 7.8l/100km but I am happy with that, I have been keeping climate control on all the time and this is for driving to work through Melbourne peak hour (I live close to the city, so a lot of start/stop driving).

Am going to do a hwy trip this weekend, keen to see how it goes...

OK to follow up the hwy trip I did, down to Lorne from Melbourne on the HWY I got 5.4l/100km which is pretty good with the auto I think and still a new car..

Driving around Great ocean road and a few dirt roads and other smaller roads I got up to around 6.3l/100km for the long weekend away...

[2i30s]

that's fairly good Joel.    how many kms have you done now mate?