The Definitive Fuel Log?
 

I know it's sad, but here we have a full year's worth of every single tank full of fuel logged against the actual mileage. So, if you have trouble slleeping.....:rolleyes:

lol that IS sad :p
its interesting that premium fuel makes so little difference.
did you get your car sorted now with the locking?

Yes, the premium fuel doesn't pay for itself as some guys have suggested, but it does give me peace of mind to know the engine is all clean and sparkly on the inside.

The locking problem is partly sorted - the 'blipper' works fine but the key will only lock the doors - not unlock them. Hoping to get that sorted either this week or next. I think this was a separate problem, but I still have no idea why the 'blipper' suddenly stopped working and had to be reprogrammed.

I did tests on premium fuel years ago in Optimax times in Denmark with 1.8 Passat and 2.8 A6 and the end cost worked about the same as regular fuel, I have used Optimax and the V-Power since, have dot done any calculations at todays prices but when I took S8 heads off there was almost no carbon build up in compression chamber, never seen so clean before so yes it seems to keep it cleaner.

Now earlier this year I was visiting friend in near Rugby and almost run out of fuel, range meter showed 0. There was no Shells near so I filled up £40 worth of Tescos Premium 99 octane fuel whatever it is called. On the way home car was a bit more sluggish then normal and did need pressing accelerator more then usual and by the time I got home after 40 mile trip tank was almost empty again, £40 gave me around 60 miles while normally I would expect 120-130. Filled up with V-power and everything back to normal.

I am averaging 17mg in automatic and 18.5mpg in tiptronic in mostly short runs around the town.

It may be sad, but I still looked, and then I used your pence per mile to figure out my total fuel cost since I bought my s8 from Ian - and it came out at £25,585 (and 11 pence...). Now that really is sad :(

How do you guys average so little MPG on a run?

i could average 20mpg if i was sat at 110mph.........

Mostly short runs around town to work and shops , lots of stop/start at lights and crossings, neither engine or gearbox gets up to temp most of the time and not hanging around so that's how I do it. On the long run I can get 24-25 @80mph, but average was 17-18mpg. Average has now creeped just over 19 as A6 is doing daily running and S8 only special occasions getting more of the longer runs.

2.8 A6 manual was doing 21mpg at the same conditions, 1.8 Freelander about the same and 2.5 TDI A6 quattro manual 33-34mpg

2.5tdi A8 delivers over 30mpg with lots of motorway at the speed limit and using Total Excellium

Well I am using cheap diesel from unknown source in cans for A6 and on the run it does 38-40mpg maybe more, locally 33-34 but it is manual unlike A8 , weight I believe is about the same. I would have expected a bit more mpg on 2.5TDI A8 maybe EGR or wastegate is sticking, I do feel like one of them is sticking on mine sometimes, I will do overhaul and most likely blank off EGR and delete function from ECU but I am leaving it for now until cambelt change, it is now at 154k miles and first change was done at 86k so looking to do change @160-170k

I'd be keen to improve. Excuse my ignorance - what's an EGR and can we easily live without it and what's the waste gate?