Long Distance Drives

[pgarner]

When i first got the bora back in august i was averaging 35mpg. this has since dropped to 31-32mpg meaning i was losing nearly 50mile a tank ( working off a 12 gallon tank (55ltrs)). after the 700 mile round journey down to london last week, ive noticed a huge increase in economy again the last 2 days ive taken the wife into work ive been getting 36 and 37 mpg compared to the usual 31-32. i originally just put this down to her needing an oil change (8000mile since last one dont worry, oil arrived this morning and getting a filter when im in town on sat).

does anybody know what would have caused this massive increase ?

the only thing i could come up with was the gunk thats built up over the last 8k miles was getting burnt off as the car was getting used for 3 hrs then 1hr break then another 3hrs

 

[HDi fun]

i reckon it's down to more frequent and longer use. Any car gives better MPG figures with regular use. Unless you twat it all the time a drive around at 6000rpm. I can't do that in my diesel thing, but I can change up at 2.5k RPM.

 

[obi_waynne]

I get this with my Audi (there is a sweet spot at 3050 rpm which seems to give me peak power to economy and I cruise there!) The following theories I think applies.

1) The car gets cleaned out thoroughly with lots of air running through the engine and an efficient clean burn so afterwards it still benefits from a clearout.

2) You havent reset the trip counter so are still benefiting from the motorway MPG bringing down your MPG.

3) You subconciously like the extra MPG and have subtly changed your driving habits.

4) The cars ECU takes an average of 200-300 miles to set the ignition parameters so although you are running around town the computer is still set to deliver constant speed timing.

 

[pgarner]

my trip counter resets itself after the ignition is off for 2hrs. i dont have the 2 settings enabled

yeah a think its came down to my right foot a bit after running at carlise and back this morning im back to the more normal 34 for the motorway trip

 

[HDi fun]

Blimey Waynne, 3050rpm in mine works out a 103mph. And, of course, I've NEVER EVER driven at that speed. EVER.

Seriously though, all engines do have a sweet spot, regardless of judicious factory mapping to score good economy numbers under standard tests.

I find mine is happiest at about 2300rpm, strangely where the torque is about to peak - which is about right for a custom mapped diesel. Equates to 78mph.

Given the current fuel prices, I'm getting used to grannying it around at 55mph. At least it's a big comfortable thing to sit in.

 

[obi_waynne]

3050 equates to 68 (speedo 73 mph) in mine. Longer gearing I guess. I do find more economy at 50 odd but I'm usually late for meetings so this is not always an option.

 

[pgarner]

is that on a 6 speed or 5 ? if its on the 5 whats the point in the 6 speed
3000 shows on mine as 69 on the climate display and 75 on the speedo

 

[HDi fun]

I've only got five in mine. A sixth would be close to idle revs at 60mph. And therefore useless below 100mph. But, as you know, I NEVER EVER break the 70mph limit.

Not ever,

 

[Izo Azlion]

I've only got five in mine. A sixth would be close to idle revs at 60mph. And therefore useless below 100mph. But, as you know, I NEVER EVER break the 70mph limit.

Not ever,

Same here!

Speed limits are there for a reason!

to be broken....

 

[obi_waynne]

is that on a 6 speed or 5 ? if its on the 5 whats the point in the 6 speed
3000 shows on mine as 69 on the climate display and 75 on the speedo

Its a humble 5 speed box in 5th gear. OH I wish I had another gear the engine is crying out for it. I've continually checking that i'm not in 3rd gear when I'm really in 5th because there is so much power I should really have got used to this by now.

The real speed is a sat nav reading. (I see you've found the codes to bring up info in the aircon window!)

 

[pgarner]

yeah have you got them or wanting a copy ?

 

[obi_waynne]

I've only got a few. A copy would be awesome! (Maybe its worth doing a new topic in Audi - crediting the source of course!)

 

[pgarner]

yeah i will post up the email i got along with the website accredited