2017 C4 Grand Picasso showing crazy fuel estimate

[GoOnYahGoodThing]

Citroen C4 Grand Picasso Flair 2017
1.6 Diesel
108k km.

Have owned the car for 10 months.. only put 20k kms on it..

Two weeks ago the car went nuts about Adblue and threw up the Engine Repair needed message swiftly followed by the Emissions problem one.
Fearing the worst I topped up the adblue tank with 5L of Adblue and used a diagnostic computer to clear all the errors it was reporting.
I then put 215ml of anti-crystallisation fluid in the adblue tank.

So far so good. No complaints from the car in the mean time.. but note that the car doesn't get run every day, I work from home, so it gets very light usage.
It probably did 200 km since. ( two weeks) so I'm worried the Adblue horror will rear its ugly head again.

Yesterday I took the family out for a spin, filled up with diesel before doing around 120km of a roundtrip.
Didn't notice anything odd. All went well.

Then later last night I had to take a spin up the road ( about 10km) and happened to notice the Fuel indicator saying that there is 940kms worth of diesel in the tank.
Thats a bit worrying cos normally when I fill the tank it says its going to last for 740km .. so.. this is decidedly odd.
Then this morning I went out and checked and the estimate has dropped to 900kms.. (I only did 10kms last night )

What should a full tank be showing as ? 740 km or 940 km?

Would the anti-crystallisation fluid have done something to screw it up I wonder?

[myglaren]

Estimated range depends on various factors but probably the most influential one is what type of driving has been done recently.

I found with my last C5, that was predominantly used for local short trips of four four-mile trips a day, work then home fore me, then work and home for my son, with the odd diversion to the local shopping centre a couple of times a week.
Setting off for a Citroen rally a few years ago I noted the range and was looking at filling up halfway there.
The estimated range increased the more I drove.

I drove there, then back, and still had fuel left for a few days. Motorway driving clearly far more economical than local trips.

[PaulC5]

If you go up a long enough hill in a low gear the estimated range will reduce but then when you go back down this long enough hill it will go up again. Similarly if you go through a town centre and when you get out onto the open roads again. Using the estimated range may not be the best way to decide if you have enough fuel for a trip, better to know how much is in the tank and an average mpg from experience.

[Paul-R]

The heavier the vehicle, the more damaging the effect on MPG and estimated mileage is.

[GoOnYahGoodThing]

Thanks folks.
Yah, I am just worried that the estimate went so high so suddenly... Its never been more than 740km even with the odd 3hr motorway run.
Now it just hops up to 940km.. I dunno..
Google says the tank should be good for 1447 kilometers but I think its got its AI in a twist...

At least I have the fuel gauge to rely on.. so I reset the distance traveled for now and we'll see if it actually manages the 900km its promising currently.

[PaulC5]

The trip computer on PSA cars only goes up to 6214 miles (9999 km, any more would need another digit) and if not reset any values shown will likely be wrong. You seem to have reset it (pushing in and holding the button on the end of the wiper stalk) so see what values you get.

Google putting AI at the top of searches is annoying knowing that it can not be believed (if anything can
on the internet) and needs to be checked. Always seems to say how good things are as well, maybe it wears rose tinted filters or looks favourably at those who pay google.

[GoOnYahGoodThing]

Ohh yeah... I reset all of them.. any one I could find..
It still thinks I have 900km in the tank.. lol.. but shure as long as the diesel gauge is still operating sensibly I'll be grand.
Will be interesting to see if I suddenly get 900km out of it.. if so I'll be adding more Wynns Adblue Crystal Clean to the adblue tank !!!