1999 Audi A4 tdi fuel consumption

[brianburke]

Hi,

My first post. I've just bought a 1999 Audi A4 1.9 tdi with 125k on the clock. I only do motorway miles and I'm a bit surprised that I'm only getting around 42 mpg on my route (370 miles, 40ltr of fuel). I don't thrash it (75mph). Air filter clean, tyre pressures good, but not done any further investigation as I can't get hold of a Haynes Manual at the moment.

Am I being too optimistic expecting more mpg for this type of driving?

Many thanks in advance to any help I receive. (I foolishly put this on the general chat forum last night - whoops!)

Brian

[kite]

Is that true MPG or what the DIS is telling you.
The DIS is not accurate, try to get a true MPG, fill up to fill up.

[brianburke]

This is true mpg - i don't have a DIS (or know what it is for that matter!)

I topped up the tank, drove 370 miles, and topped it up again, using 40 ltr fuel. I do the same journey twice a week (glasgow to swindon) and i know i'm using about 40 ltrs each journey.

I just think i should be using a bit less fuel. Any thoughts as to the next step to take?

Thanks

[kite]

OK, DIS= Driver Info system, the display between the clocks that shows avg, actual miles to empty, you might not have it.
Try driving at the speed limit instead of over, that can increase MPG.
You could have a failing AMM, (air flow meter that helps regulate fuelling)
Maybe try a fuel additive, to clean up fuel lines and injectors.

[hagis]

Hi Brian,

You're probably best posting this in the A4 B5 topic for an answer:

https://www.vwaudiforum.co.uk/forum/f...play.php?f=109