Hi all.

 

Focus MK4 ST-Line 2020 1.5 EcoBoost 182HP here,

Was fiddling with Forscan for the last few days and noticed that in the IPC config, the fuel tank size is 39 liters.
Confused as to how could that be, (I looked at the dealership brochure I kept from when I bought the car, it said 52 liters) I went ahead and took a quick peek at the owners manual, according to it, the ST-Line version with the 1.5 EcoBoost (182HP) is supposed to have 52 liters. I never change any of the fuel options while playing with Forscan but is it possible my vehicle came to me misconfigured from the dealership? Or maybe its forscan who’s messing with me?

Have you tried seeing how much you can fit in?

Also 52 litres is usually with all pipes etc

I've never got more than 48 litres in my car with it on zero miles, although there is likely to be a good couple of litres reserve. Perhaps forscan is based on the fuel guage not actual tank size?

5 minutes ago, alexp999 said:

Have you tried seeing how much you can fit in?

Also 52 litres is usually with all pipes etc

I've never got more than 48 litres in my car with it on zero miles, although there is likely to be a good couple of litres reserve. Perhaps forscan is based on the fuel guage not actual tank size?

From what I reckon from Forscan, the IPC is configured with the tank size, and calculates the fuel consumption, distance and remaining fuel according to it. also controls the actual gauge based on said size.

I never really got close to 0 to know the aprox. tank size ( I usually refuel when half empty or when I'm about to reach the last quadrant of the gauge).

Any way to know the actual size without running her till only fumes are left?

 

It's worth mentioning that the car config is just a series of bits.

Forscan have programmed their interpretation of those bits.

Just because forscan says 39L doesn't mean that's what the car understands.

The config will just be for example bit FA. To the car software that could mean 52L and forscan has interpreted wrong or not accounted for different cars knowing their own values. e.g. the bit could just represent "standard fuel tank A" on some cars that is 39L, but the car know it is actually 52L in your case.

I wouldn't worry too much about what forscan thinks, you get the same with configured battery capacities and tyre sizes sometimes.

There is always a reserve taking it close to zero miles to get an idea of tank size once won't cause any harm, I frequently don't fill up until around 30 miles.

Maybe its capacity stamped or moulded on the tank somewhere visible? Or a part no. that you could look up?

It could also be linked to the conversion between US Gallons  / Imperial Gallons / Litres

For example:

11 Imperial gallons is approx = 50 Litre

11 US gallons is approx = 41.5 litre

So if one design team is working in US gallons and the FORScan team is working in Litres who knows what misinterpretations could occur.

 

Here's a thought. Why not brim your tank, drive it till empty (with a suitable gallon tank in the boot), and then measure how much you need to brim it again. I know it's old school, and doesn't involve any fancy computers, but we launched a rocket to the moon on 'old school' technology...

Warning - this post contains no humour whatsoever, just a bit of common sense which I hope does not offend anyone.

1 hour ago, StephenFord said:

 

Warning - this post contains no humour whatsoever, just a bit of common sense which I hope does not offend anyone.

That's a first for you! 🤣🤣🤣🤣

I think that @unofix is correct, some of the capacities in my handbook are US Gallons not Imperial ones as well, luckily I can convert Imperial and Metric roughly in my head so I don't make mistakes.

If your running fuel consumption is quite consistent then an easy way of checking what size of Tank your car thinks it has is to look at the estimated miles (Km) to empty when you fill up. For example my long term MPG is around 43 and when I fill my tank it gives an estimated range of around 500 Miles, so without getting my Calculator out I must have a Fuel Tank of between 11 and 12 Gallons (52 Litres) and my car must think so too. I haven't checked what FORScan says.

You must be able to do a similar rough calculation in Litres/Km.    

I would strongly recommend NOT changing that value