Just got back from our almost 2000 mile road trip, avg'd 35 mpg running about 80 mph over most of the trip 
I noticed a couple times when the low fuel warning light came on (along w/ the warning "ding") I had 40 miles to go on my range marker. Got down to 15 miles one time, filled up and I only got 12.5 gallons on the fill. Got down to 20 miles on another warning, only got 12 gallons on the fill. So I guess VW figures 4 to 5 gallons in the reserve is adequate, and I guess that's better than actually running out when it says 5 miles left lol.
But also nice to know I actuyally have a 550+ mile range vs. the 420 miles that it states on the dash
I noticed a couple times when the low fuel warning light came on (along w/ the warning "ding") I had 40 miles to go on my range marker. Got down to 15 miles one time, filled up and I only got 12.5 gallons on the fill. Got down to 20 miles on another warning, only got 12 gallons on the fill. So I guess VW figures 4 to 5 gallons in the reserve is adequate, and I guess that's better than actually running out when it says 5 miles left lol.
But also nice to know I actuyally have a 550+ mile range vs. the 420 miles that it states on the dash