smatsuda

hi everyone -
this is my first diesel auto and I after talking to my salesman at the dealership, I am still confused about fuel - -
what are the various grades of biodiesel, and what can be used safely, without damage to, the Q5?
I was under the impression that we are supposed to buy ONLY "pure diesel" - but when I get to the gas station, the attendants tell me "there is no PURE diesel - - it is all mixed"
so how are you supposed to know what is harmful to the engine of a Q5?
and are we supposed to be putting additives (cleaners or performance boosters) into the tank when we refuel?
One guy told me to just make sure it's "#2" diesel, whatever that means...
I'm now paranoid about what to put in the vehicle and where I can find the CORRECT TYPE of fuel when out driving and seeing the tank near empty -
I would be so very appreciative of any information you can provide!

also, on another topic - - the FUEL GAUGE:
what's the deal with the fuel gauge on these cars...???
I fill up, and the needle stays up in the "Full" mark for at least a hundred miles before it starts to budge - -
then by the time it's moved down to a HALF-TANK on the gauge, I have driven at least 300 miles - -
but the next half of a tank only racks up 100-130 miles - -

so I'm thinking, either the fuel gauge is broken...
or if this is the case with all the other Q5s out there, then I cannot trust it to be reflective of how much fuel is remaining in the tank - -
i.e., the HALF-TANK mark is actually the 2/3s or 3/4 tank mark - -
which makes me crazy... why didn't they make the gauge accurate?

again, any help or input or comments you can provide would be most appreciated!

thank you in advance,
Stacy
smatsudd@comcast.net