1987 325E 5-Spd
I never tried it, but I know the reserve was 4.5 litres. My car does 10L/100km in the city and 6.9L/100km on the highway; if you figure the math, it should do either 45 or 66km on R.
She is a 1987 325 coupe, lux, with a 5-speed.
This is a great idea! It makes sense that a loud noise jolting you awake would leave you tired. As long as it's as cbmfortaole as a normal pillow, I'll definitely purchase one. Nice article!