2.0 TDI 170 Fuel Consumption

[JohnH]

I have a 170 TDi SE Avant, new in March '07 and it has averaged 41.5mpg over 11K miles, I have to admit to being pretty disappointed as my company thinks sub-2.0l diesels can average 45mpg and cites UK tax rules for this expectation....

It also seems to use 1L of very expensive and hard to obtain VW 507 oil every 8K miles.

Upon reflection fuel economy is probably improving but it still falls way behind my wife's Honda 2.2 CDTi which regularly gives 45+ mpg and does more urban motoring - averaging 50+ mpg in the kind of motoring I do.

As for aircon, it seems to make little difference, cruise control seems to have a negative impact though - surprising for 'drive by wire'.

Also, I don't find the engine very 'driveable', it's easy to get caught without enough power - say when approaching a roundabout and a gap appears, if you've less than 2K rpm it is gutless, then it all arrives in one big 'wallop' at 2K RPM, go drive the Honda to experience something a little more 'linear'. in fairness from 2K to 4.5K RPM the power delivery and 'sound' are good, but then the economy is poor.

I like my Audi, but I too feel that they've squeezed too much out of this engine, perhaps the 140 is 'sweeter' ? The cynic in me wonders whether the gutless low end might have something to do with the excellent emissions results.

I hope that the new common rail version in the forthcoming A4 is better as I'll probably opt for one of these next, although the TSi petrol engines appear to be offering good torque and power too.

[prolfe]

Keeping your tyres PSI right with weekly checks is another good tip as is not having air con on. You can also radically improve your mpg by knocking it into neutral on downhill stretches, not in the advance drivers guide, granted. I appreciate you're all talking about what the engines can 'do' but some of these suggs may help get yours up (so to speak) ;-)

knocking the car into neutral will make the car tickover - at tickover it will be around 200mpg.

Keeping it in gear and just backing off the accelerator will cut fuel altogether and the MPG is unrecordable. ie. a lot higher than 200mpg.

as it is in gear it uses no fuel and power to keep the engine ticking over - it lets the momentum of the car do that. Like bump starting it i guess.

I've averaged 41mpg in my car and the oil consumption has been better after it's first service.

Also, now that I know it can be remapped to around 210bhp i'm wondering if this could also improve the mpg.

Superchips say that they have yet to rolling road a 170 TDI that does not put out less than 180bhp as standard. So maybe that would explain the lower than quoted mpg.

[mcmahonleon]

Now done 11.5K miles in the A4 & no real improvement on the fuel consumption, however I suspect there has been something fundamentally wrong with the engine since new. On Christmas Eve, I was out on a short journey & the oil & coolant warning lights flashed-up - pulled over & to my horror found oil pouring out of the engine & the radiator expansion tank full of oil!

The car is now with my local Audi dealer & I suspect the news will be scary. In the meantime, I'm driving around in a Vectra supplied by Audi Recovery (who rejected my request for a replacement Audi whilst mine is in for repair). All in all, not entirely impressed with my Audi experience thus far - seriously regretting jumping the BMW-ship.

If you're interested, I'll let you know the outcome.

[Mark Hunt]

Hi All

I've logged up 20K in my Audi A4 Avant Quattro 2.0TDI, it's averaging 36mpg and already has had a turbo replaced after a month-long saga with my local Audi dealer claiming there was nothing wrong with the car. In what can only be the Audi equivalent to an I.T depts " Have you tried turning it off and on again", they normally try to fix it by "Downloading the latest software map", which achieves nothing. Not impressed with the car economy or back up, this is my 6th Audi Avant and my last..I think they have pushed the engine too far and lost their way on emissions (vs. BMW), torque (it appears higher up the rev range) and economy.

[ptflooring]

Hi all, just joined this forum for a similar problem, which I have started a new post.
i have a 3 month old A4 140 tdi avant with multitronic, and around town I have just worked out getting around 25 mpg and do not drive hard. My previous car was the same but a manual and that was in the forties, I know they quote a less mpg for a multi but I think I have something very wrong, hope my audi dealer will be as helpful as they have been in the past. My last long run was 550 miles, and did this on one tank, all motorway.

[seventh-heaven]

You can also radically improve your mpg by knocking it into neutral on downhill stretches, not in the advance drivers guide, granted.

Not sure that this is true. Most modern engines petrol and diesel don't feed the engine with any fuel on overrun above a certain rev range and therefore you will use more fuel by letting it idle.

[prolfe]

Not sure that this is true. Most modern engines petrol and diesel don't feed the engine with any fuel on overrun above a certain rev range and therefore you will use more fuel by letting it idle.

Absolutely true.

200mpg at tick over
999999mpg when coasting in gear. Fuel is cut off altogether

try it when you flick the trip computer to real time mpg.

[bogey888]

Hi, am new to this site but glad to have found it, has been very informative!

Bought a brand new A4TDI 170 S-Line Special edition in October. Have been really happy with it apart from the MPG you guys are moaning about.
I was just wondering if this will improve to what the tech Spec says in the brochure or have we been sold a dummy!? Also is there anything else to worry about with this particular car/engine as I've read they have stretched this engine to the limit!?


Cheers

[prolfe]

Hi, am new to this site but glad to have found it, has been very informative!

Bought a brand new A4TDI 170 S-Line Special edition in October. Have been really happy with it apart from the MPG you guys are moaning about.
I was just wondering if this will improve to what the tech Spec says in the brochure or have we been sold a dummy!? Also is there anything else to worry about with this particular car/engine as I've read they have stretched this engine to the limit!?


Cheers

Welcome to our little site.

I have averaged 41mpg since new and I rarely hang about.

Driving economically i can expect this to be in the low 50's

[John140]

Keeping your tyres PSI right with weekly checks is another good tip as is not having air con on. You can also radically improve your mpg by knocking it into neutral on downhill stretches, not in the advance drivers guide, granted. I appreciate you're all talking about what the engines can 'do' but some of these suggs may help get yours up (so to speak) ;-)

Surely knocking it out of gear on downhill stetches will increase fuel consumption, as the engine is using a small amount of fuel to idle, whereas on the overun these engines completely cut off fuel injection.