1st Mission Accomplished!

[03NHVW]

Joenavy, I believe you...but until I can pick up a ScanGuage that really is my only way to judge a baseline of how much fuel is in the tank...so far, since my commute is pretty steady (34.5 miles one way) and I put in a pretty steady amount of fuel, I can pretty much predict when the light will come on with accuracy...(" That light is gonna come on/beep when I get to the stop light outside the parking lot after work") and I'm usually not more than a mile off...so far now I'm basing my computations on that.
When I *do* get a ScanGuage my OCD is gonna have an all-out, no holds barred, FIELD DAY.
All I really wanted was 33mpg, so I'm pretty happy, compared to driving my 95 Tacoma which struggled to get 24mpg.
Maybe instead of stopping at $20 at the pump...I'll stop on an even gallon number if possible...maybe the resulting lack of decimal places will give me a more accurate number...but I've been smack between 34 and 35 mpg 2X a week since February with the one exception when I coasted down literally every little grade on my commute. I was actually annoying my own self then.
I like this place...people take it seriously.

[Phantom]

If you do not start with a full tank and at one point fill the tank again then you have no idea how much fuel you have actually used. If you are only wanting to put $20 in each time then fill once do your $20 fuel adding and keep track of the miles and gals till you completely fill the tank. Then you can take the total miles and divide by the total fuel to get an actual MPG.

[03NHVW]

I like that idea Phantom...I've done that a bunch of times...but I got it in my head that the top half of a full tank is added weight that I can trim off.
I will start that again...advice taken...will fill tank in the morning and give it a week's worth of miles...I can go the whole week-ish on one tank.
Will report my findings.
Thanks!

[Phantom]

While you will have a little more weight ~6lbs per gal if mostly highway driving you should not notice it, but think of it this way every extra time you stop to get fuel you are slowing down and driving at parking lot speeds getting bad MPGs at that time and them restarting and pulling out doing the same and adding idle time.

That time and gas used in each stop assuming it takes 1 min extra of the car running to get gas and that you get 40mpg at 40mph you could drive one extra mile per fill or after 40 fills save one gal on gas.

[03NHVW]

OMG Phamtom...that all is just crazy talk...=)~
...but in the AM I'm gonna fill the tank and see what happens. Actually, I might take a ride and visit the fambly this weekend for Easter...so a full tank will get used over the course of the trip, plus some back at home.
Actually, once I already got from my place in NH, across VT, to my folks' place in upstate NY...and BACK to NH...with enough gas to get to work in the morning. This isn't a big deal...425 miles, NH-NY-NH...I actually did this with my Tacoma as well (with a load of firewood on the back)...but with the Vdub it's do-able, repeatable *and* able to be improved upon.
Supposing the owners' manual and my VW mechanic are correct...the tank holds 14.5 gals including 1.9 gallons in reserve...I'm gonna shoot for 460 miles (NH to NY and back + home to work 1X) on one tank (before the reserve)...that should be +/- 36.5 mpg. That would make me wicked happy...like the Easter bunny left me a six pack of Cadbury eggs and a bottle of Baileys.

[BadDog98]

Great Job!

[03NHVW]

OK, this is just preliminary but...
This morning I filled the tank on the way to work (12.7 gallons +/-) which somewhat supports the notion that my "low fuel" warning is mostly accurate.
Then I drove around for the day doing my usual stuff, mixed driving between backroads, small town 30mph and interstate...before heading home I filled it again (both times I let the pump click off on its own). As long as the pumps and the trip meter are correct, I put in 1.9 gallons tonight, having driven 70.5 miles. My calculator says those 1.9 gallons gave me 37.1 mpg. I'll take that.
Early in the AM, I'm gonna take a trip and burn through the tank and see what happens.

[wanna bECO]

I wouldn't trust too much until i'd driven at 100 miles... and maybe even a bit say 200. I think a longer usage is needed for an accurate count on mpg, but what you've done is a good place to start. If you do 70 miles a day, just wait 3 days and it'll definitely give you an accurate reading.

[03NHVW]

I hear ya, wanna beCo, I should have pointed out that when I first bought the car I filled the tank and drained it twice...mostly to see what the "performance" of the car was and whether I could find anything mechanical that needed to be addressed immediately...not for mileage. Still, driving it hard I still got 29 mpg. ...same as my wife's 1.8L turbo gets.

Anyway...last Friday I filled the tank til the pump clicked off. Currently I've driven 340 miles and have just a needle-width under half tank left. Based on my schedule for the rest of the week I'll probably fill it again on Friday morning (unfortunately just in time for the stations to raise prices for the weekend, again). Based on experience, the gas left in the tank now will take me about another 125-140 miles.
I'll update when I fill it again...try to take a dashboard instrument picture too.

[03NHVW]

OK, to bring this full-circle, so to speak.
I never did make the road trip that would have used a full-tank...but I drove the car since last Friday for one tank of gas down to the "fuel low" light...my cut-off for reading the miles driven. I plan to fill it up again tomorrow and start again but the next go-round will take longer as I'll be out of town next week.

Anyway...from full-tank to the "fuel low" light is approximately 12.5 gallons according to our VW mechanic and 12.6 according to the manual, also evidenced by how much it takes to refill the tank, give or take a tenth or two.
When the light went on/beeped today the miles read 463.9. ...divided by 12.6 gallons = 36.8 mpg. I'm believing this, as my previous experiments have yielded approximately 33-37.something. I believe this is not only repeatable but improvable, as my wife drove the car between 30-40 miles of the tank and she flogs it like a rented mule.
The mechanic says one of their techs is a mileage nut and will have a couple of tips for me, including his pick for best LRR tires, which is the next improvement planned. (currently Nokian "rain groove" type tires)