When to fill the fuel tank?

[gwatpe]

Many drivers use "flatten Battery first mode" [NORMAL] mode, and would not see the effect that some battery has on the operation of the ICE as the petrol tank gets towards empty.

 

[anko]

Many drivers use "flatten Battery first mode" [NORMAL] mode, and would not see the effect that some battery has on the operation of the ICE as the petrol tank gets towards empty.

True, I guess. But in colder conditions, when you know SOC is not enough to complete the whole trip anyway, it can be wiser to use Charge for a while midway your trip, so you can benefit from the engine heat during the trip (and not afterwards, when the car is parked on the drive way) and finish the trip in EV mode. This way you will need less electricity for heating and can save on fuel.

I do this, but try to wait until SOC drops below 50% or so (when temps allow). Finding the optimum, I think it is a very difficult equation.

 

[Sharky]

It gives the "low fuel" alarm from the moment that about 7 litres (two gallons?) are left in the fuel tank. So I usually only start looking for a petrol station when I get the alarm. Filling up everytime when the tank is still about half full, will result in an average of 20 kgs extra weight (decreasing mileage), more stops and it will take more time.

I agree to some extent, but the only reason I usually fill up when I am near a quarter full is that I pass petrol stations on my way home so I'm not going out of my way and due to the nature of my job I maybe required to jump in the car at a moments notice and be the other side of the UK so with something in the tank already I have options before stopping to fill up again. The 20Kgs "extra" in fuel I don't feel is an issue when the car weighs 2310Kgs (I know it all helps) I challenge anyone to notice a drop in MPG due to an increase in less than 1% of the cars weight and if you have a 4Hs you have already added 61Kgs of extras against a basic model. Don't forget there seems to be a lot of people in this forum carrying a spear wheel just in case!