Tunbridge Posted January 16, 2006 Report Share Posted January 16, 2006 I have had a 1998 Audi A4 1.8T Sport (150bhp) for 6 months and am concerned about the fact I only get 26mpg average. A Friend has an identical car and manages 35mpg average, both cars are driven the same route to work alternate weeks as we car share. I have had the car to an independant garage and they can find no faults. There are no error codes on the cars ECU, the emmisions are perfect, the engine runs fine, there are no fuel leaks, the brakes aren't binding and the lambder sensors is switching ok. The only thing I can notice is a smell of fuel from the exhaust when i reverse it into my garage. Anyone got any ideas? Link to comment Share on other sites More sharing options...
cruiser647 Posted January 16, 2006 Report Share Posted January 16, 2006 Might be running too rich, which will show itself up as poor fuel consumption. What happens to the revs, when you come to a stop? Does it rev perfectly still OR do the revs go up and down a bit when you first stop? What is the performance like? You could clean the MAF (Very carefully, with alcohol) and see what happens........ Link to comment Share on other sites More sharing options...
Tomk Posted January 16, 2006 Report Share Posted January 16, 2006 im my 1.8t if i drive badly thats the milage i can expect, try unplugging the battery for 10 - 30 mins to reset the throttle body , put some decent fuel in it ( optimax or tescos super 99 ) and give it a gentle drive upa motoway or a 30 odd mile gentle cruze not going over 70 ish - that should give you a figure on the trip of aprox 36mpg if its still giving you the problem its going to be tricky if the car in itself feels ' right' Link to comment Share on other sites More sharing options...
Tunbridge Posted January 17, 2006 Author Report Share Posted January 17, 2006 Cheers, The engine revs to rise and fall slightly at tick over but i've always put that down to wear and tear (its done 99,000 mile). If it is running rich how is this resolved? The performance is fine, the best consumption i ever managed was on a long run at 70mph driving very very carefully, this achived 29mpg on the trip but i have since found that the trip computer reads about 1/1.5mpg over what i'm actally getting (that was on normal Tesco Fuel). Also forgot to mention I'm running 18" TSW Alloys with 225 Tyres, I figure this must cause slightly more drag than the standard set up but nothing significant. Link to comment Share on other sites More sharing options...
Tomk Posted January 17, 2006 Report Share Posted January 17, 2006 slight BUT i would not think that sthe problem , when my throttle body starts playing up i get poor performance and economy , id try the above then try and get a garage to look in to it , Link to comment Share on other sites More sharing options...
steve2 Posted January 20, 2006 Report Share Posted January 20, 2006 i have just reset my throttle body ,doing what Tom said and the car runs smoother and picks up cleanly, now to cleanthe maf and heres to the next 100,000 miles Link to comment Share on other sites More sharing options...
Tunbridge Posted January 21, 2006 Author Report Share Posted January 21, 2006 I reset the throttle body last night and it has made things smoother, its a bit to early to tell if its made a difference to the economy but it defiantly drives better. I'll update you in a week when I've done a few more miles. I have managed to improve the fuel consumption by about 2 mpg (now up to 28mpg average) last week after a used an engine treatment (the type you put in the fuel), somebody at my local garage had suggested this might help after saying the poor consumption could be down to blocked fuel injectors. He said that if the injectors are blocked the fuel will not atomise as it is injected into the cylinder. Has anyone come across this problem in the past? Apparently the only way to do it properly is to take the injectors out and clean them ultrasonically although I'm not sure how much this would cost and if it will make much more difference. Link to comment Share on other sites More sharing options...
Avus_Bub Posted January 21, 2006 Report Share Posted January 21, 2006 Sounds like a good idea. Why don't you run the car on Optimax or Ulitmate? They both have cleaners built in and you should get better economy just by using them anyway (extra cost offset by better economy). BUB Link to comment Share on other sites More sharing options...
sufu Posted January 22, 2006 Report Share Posted January 22, 2006 [ QUOTE ] Sounds like a good idea. Why don't you run the car on Optimax or Ulitmate? They both have cleaners built in and you should get better economy just by using them anyway (extra cost offset by better economy). BUB [/ QUOTE ] I wouldn't use BP Ultimate, Ive tried it for a few tanks and to tell the truth there was very little in it, i'd got for Optimax everytime now, much more responsive and efficient, just my opinion though Link to comment Share on other sites More sharing options...
Philbes Posted January 22, 2006 Report Share Posted January 22, 2006 I had a 2002 A4 1.8T (!63) from new for 5 months and 9,500 miles. I kept accurate petrol purchase records (it was a company car) and it averaged 32½mpg over that time/distance. Did include a lot of motorway driving cruising at 85 when possible. Link to comment Share on other sites More sharing options...
Tunbridge Posted January 30, 2006 Author Report Share Posted January 30, 2006 UPDATE Its been over a week since I reset the Throttle Body and although the car feels a little bit sharper it hasn't made a noticable difference to the economy. I'm now averaging 26/27mpg but this could just be variations in the traffic, etc. The car is in for a major service in a few weeks time, i'll see if that makes any difference. Link to comment Share on other sites More sharing options...
neo283 Posted February 10, 2006 Report Share Posted February 10, 2006 I'm getting pretty poor MPG at the moment. Although my A3 1.8 doesn't have a computer, I fill her up with £42 worth of standard motion lotion (not sure of the capacity so I assume it's around 50 litres/11 gallons), which returns 320 miles at best. Thats 29mpg on a bog standard 1.8 engine. To me that's not too hot, and I'm sure it used to be better than that. Am going to change the air filter some time soon following a recent post elsewhere (I have a K&N panel), so I'll see how that goes. Link to comment Share on other sites More sharing options...
slol Posted February 10, 2006 Report Share Posted February 10, 2006 Is yours man or tip,mine is tip and have never had above 25 average around town,even with correct servicing and new maf. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now