451 Fuel capacity/reserve

[Posh Pete]

I did a wee experiment at the weekend. The bike was low on fuel, showing 30 miles on the count down. I filled a plastic container with 4 litres of fuel and set off down the road on an approximately 50 mile return loop.

After 30 miles the countdown reached zero and stopped there. I kept going, confident that the petrol strapped to the rack would see me right. The odometer showed a further 20 miles before i approached my usual filling station on the return loop. I filled up there and the bike took 15.2 litres.

With a specified 17 litre capacity in the tank, that suggests that the bike could have completed close to 50 miles (20 + 1.8 litres at 17.5 miles/litre approximately) in total before running out AND after reaching zero on the countdown.

I may do a run dry experiment at some point although I'm a tad reluctant in case it buggers the fuel pump. We'll see!

 

[RedRick Esq.]

Indian Litres

 

[Wapping]

Indian Litres

And Eskimo pence.

To misquote Mr Strummer.

 

[RS-eyJohn]

Yep my '19 RS also takes more than expected when I run it low.

NB the fuel pump runs at variable speed dictated by the engine management system, but only stops when you turn off.
The problem is that the pump is cooled by the fuel - so before the bike chugs to a halt, the expensive pump could be damaged...
Don't ask me how I found this out...

 

[Neil W]

Yep my '19 RS also takes more than expected when I run it low.

NB the fuel pump runs at variable speed dictated by the engine management system, but only stops when you turn off.
The problem is that the pump is cooled by the fuel - so before the bike chugs to a halt, the expensive pump could be damaged...
Don't ask me how I found this out...

Learned that one with an old Scirocco injection , the main high pressure pump is supplied by a secondary low pressure pump in the tank , if the pump in the tank fails the car will still run as the high pressure pump has enough power to suck fuel out of the tank through the low pressure pump.
You have maybe 300 or 400 miles before the strain burns out the main high pressure pump .