Audi A3 - Loss of MPG

MarkA

MarkA

MarkA

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Hi guys,

I have an A3 2.0 TDI 140.

I got a quick question and would like suggestions on why this issue has occurred.

I have had 2 new front tyres put on my car, but I think this may just be a coincidence.

I have suddenly lost about 10MPG over the last week. I only noticed it after I had new tyres on it. Pirelli P6000's.

Does anyone have any idea why this may have occurred? Perhaps something else has 'gone' in the meantime?

Appreciate your suggestions!

Thanks,
Mark
 
What was your previous MPG, what is your current MPG?

What tyre pressures do you have?

What were your previous tyres

Where you caught with two blowouts in the middle of the Australian outback whilst being chased by murdering goats, and the only tyre shop only had P6000's, as this is the only scenario where buying P6000's - totally dire tyres that cost a fortune - can be forgiven?

We need more info!
 
Haha, I have no idea about tyres but got done by the guy in the tyre garage! I will keep far away from them in future!

I've upped the pressure, as one was 3 below standard and now both are good.

MPG, since I do 25k a year, i got myself a little benchmarking system.

I live pretty close to the motorway so traffic has very little impact on my test:

Head to work from my house, hit 30MPG by the time i hit the roundabout (about a mile from my house) and hit 55MPH... turn on cruise control and travel 45 miles to work.

For this benchmark (that I do every now and again) I can get pretty close to 65MPG.
Since I've the new tyres, I've been getting about 56MPG. Quite a drop in MPG, especially since I'm going to be doing so many miles.

I'm not sure of my previous tyres exactly, but I got a feeling they were some sort of dunlops.

If u need more info, tell me what and I'll get it.
I've just checked my air filter, but I'm no expert but it didnt seem that dirty. Since they are a tenner, I'll get that changed anyway.
 
To be honest 65mpg sounds like it's rather outside the realms of possibility for an A3 2.0 TDI. 56mpg sounds much more realistic.

Perhaps your old tyres were the wrong size or something, leading to miscalculations in fuel economy?
 
I disagree fox, I think 65MPG can be done in an A3 2.0 TDi if you're sat at such a low speed.

If you had some sort of eco Dunlops before, it could well be that the P6000s are a lot worse.
They're **** anyway, but they could have a higher rolling resistance too.

I take it you don't have a trip computer, MarkA?
 
No, I don't have anything like that.

It' not just the calculations that are out too. I'm actually doing less miles to the tank, even when running at such low speeds. I may just get new tyres fitted and sell these.

Just for reference, what tyres would you suggest?
 
MarkA said:
No, I don't have anything like that.

It' not just the calculations that are out too. I'm actually doing less miles to the tank, even when running at such low speeds. I may just get new tyres fitted and sell these.

Just for reference, what tyres would you suggest?
Click to expand...
You could try ContiEcoContact 3s if you want to aim for low MPG, rim-size depending.
Otherwise PremiumContact 2s will be fine.
 
I had a faulty coolant temperature sender and thermostat housing on my Fabia. The sender fault meant that the temp gauge stayed rooted to the left. Effectively the car would stay in choke mode until the engine was restarted and then the needle would suddenly spring up to normal temperature.

The thermostat housing problem meant that the thermostat was staying open, causing the engine to cool down at faster speeds, again resulting in high fuel consumption. Both contributed to about 10th MPG less than normally achievable on motorway journeys.

If your temperature gauge is behaving normally, that's not your problem but apparently a lot of VAG cars are prone to it.
 
[TW]Fox;17589889 said:
To be honest 65mpg sounds like it's rather outside the realms of possibility for an A3 2.0 TDI. 56mpg sounds much more realistic.

Perhaps your old tyres were the wrong size or something, leading to miscalculations in fuel economy?
Click to expand...


The new ones can do it. I averaged 67.7mpg on a few days commuting (80 miles a day), I didn't believe the trip comp but my own calculations at the pump were pretty much the same.

That's the 2.0TDi 140 as well, company car delivered a few weeks ago.

No idea why this will have dropped though!
 
Yep - for similar reasons to the Fabia problems I mentioned. Both problems result in lower MPG because the ECU behaves as if the engine is cold.
 
The A3 2.0 TDI 140 would reach 58mpg with ease on a motorway, town driving you would be lucky to go above 40!

Reasons for loss are so varied such as weather change, driver habbits, passenger/luggage load, plus others my mind cant think of.

If you're that worried (I now get 14.1 mpg and miss the 40mpg :() hook it up to a VAGCOM or if its under warranty as the dealer to give it a proper look.

*edit*
Also check if you used different fuel or even a different garage, possible ecu fault, or you may just be seeing a different mpg indication on the DIS but the actual mileage achieved may be the same!
 
iaind said:
The sudden change of temperature recently combined with fresh rubber would probably explain it
Click to expand...

Sounds plausible.

Swapped the OEM Bridgestones for Goodyear F1's on the Fabia and the mpg average is down about 5mpg. Average also drops in the winter months apart from 10+ mile journeys, as it takes the engine a lot longer to fully warm up.

I wouldn't have figured they were still making P6000s. They were standard fit on my Dad's Volvo back in the mid 90's.

Could also be the Coolant Temp sensor, but you'd get an ECU light if that was the case.
 
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