I have an 04 disco II the Rave says that its fuel tank capacity is 95 liters that would equal 25 US gallons but I have yet to be able to get anything more than 20 gals in her on empty. Im trying to get my ultra gauge set up properly, what is the tank size? will the OBDII automatically set the right tank size? Newbie here looking for some guidance.
Gracias!

 

25 gallons is correct.

 

Thats bone dry though, so the only way you'll fit 25 gals in is if you run out.
When my low fuel light comes on I have about 5 gal left.

 

Unfortunately, the UltraGauge will not read the Fuel Gauge. The Rover does not send that info. At least not that I've been able to do.

 

Wow, its that much?

On a normal car the light hits at about 2 gal.

 

A normal car also has 2x the MPGs so it works out.

 

Makes sense, maybe that explains why I've been getting 17 MPG..... Not I will need to enter the accurate tank size for an accurate reading. Is it true that you need to clear the ultra gauge each time you fill up? Or will reset when the tank is full?

 

You just push the up arrow and hold it down. Then it tells that UG that you filled up and it will reset the fuel amount to full. And I believe the tank is 25.5 gallons not that the .5 will make that much of a difference in accuracy, but just in case you want to be precise.

 

The instantaneous MPG on the UG should be fairly accurate since it can read other sensors and calculate what the amount of fuel being used SHOULD be. There is no connection from tank to computer so the UG would have no way of knowing if you filled your tank (unless you reset it) and based on its calculated fuel consumption it can tell you when it is will be empty.

 

I dont have an ultra gauge so this might be completely off base, but wouldn't you want to set it to whatever the amount of fuel you always put in? (i.e. i always fill up around with about 20 gal so i would put 20 gal in so that it was dividing the milage over the correct gal)???

That is assuming the UG calculates by know the milage driven over a preset refill capacity? Or do you enter your mileage at fill up and it just does the calc for you?