Milage

[merlinq21]

Good afternoon all- just had the Water Pump and T stat replaced as well as the secondary air intake cleaned out to carbon build up. Since my last service about oct 2016 my gas mileage has dropped liked a stone over the last 5 fill ups?

The last time I was in for service the adviser mentioned that the o2's we giving some errors but not enough to trigger a cel - anyone having issues with sudden drop in l/100km's?

If so what did you find and how did you resolve-

Truly the dealer is trying hard, but it is like I am there every 14 days dealing with one thing or another.

Any insight would be very helpful.

Thanks

[Tanner]

Do you know your mileage from a year ago? I know my mileage has gotten a bit worse at the start of October, believe this is due to the winter gas we have now.

[merlinq21]

Do you know your mileage from a year ago? I know my mileage has gotten a bit worse at the start of October, believe this is due to the winter gas we have now.

Yes I do the milage last year at the same time was much better- what has changed is that I have gone from 65 % city to 15% city I have moved from MIsssissauga to Stoney Creek and I am on the highway both ways to and from work. I am on the higway about 4 30 am it is good constant flow to work. On the way home I am on the 407 - same flow.

I have been averaging 10.2 l/100 km best ever was 9.8- last three fill up's have been between 10.9 and 12.3-

[Tanner]

10.2L/100 is pretty good. I've been getting ~13L since early October but most of my driving is city. Highway driving, depends on my right foot, but as low as 9.6 to 10.5.

[merlinq21]

Pardon the formatting

fuelup_date l/100km km litres price city_percentage
11/09/16 12.01 482.996 58.027 $1.24 10%
11/04/16 11.28 482.9 54.449 $1.28 10%
10/31/16 10.2 497.995 50.778 $1.25 10%
10/28/16 10.42 541.995 56.501 $1.27 10%
10/24/16 10.7 525 56.16 $1.27 10%
10/17/16 9.94 549.607 54.646 $1.26 10%
10/11/16 10.14 546.002 55.347 $1.26 10%
10/07/16 10.08 525 52.947 $1.27 10%
10/03/16 10.78 457.102 49.286 $1.25 10%
09/29/16 9.33 584.997 54.601 $1.23 10%
09/19/16 9.87 542.993 53.571 $1.26 10%
08/17/16 10.23 525 53.715 $1.17 10%
07/26/16 10.98 465.004 51.061 $1.22 10%
07/15/16 9.98 547 54.62 $1.21 10%
10/06/14 10.73 496.804 53.287 $1.41 45
10/03/14 12.29 445 54.707 $1.46 60
07/13/14 13.12 374.993 49.21 $1.53 70
06/25/14 11.46 439.995 50.437 $1.59 50
05/22/14 11.79 462.992 54.589 $1.22 65
04/28/14 12.19 421.004 51.319 $1.56 20

[merlinq21]

sorry about the formatting below - but I could not get this data to post correctly - I agree 10.2 to 10.5 is pretty good and I would be happy about that - just the last 4 fill ups have been terrible- have an appointment with the Miss - Audi Tuesday i am convinced there is an issue there somewhere.

Thanks for the feed back

[Tanner]

I honestly believe it's the winter gas blend that we're using now, having a worse gas mileage is a given. In all of the three cars I've tracked mileage on, both forced induction and naturally aspirated, the mileage would improve in late spring but then start to get bad again around October.

[DesiredCustoms]

surprised i haven't seen ya on the hwy yet :)
i live in niagara and work in sauga..

work 6-2 and commute with HOTPass on the hov and 407 when needed.

just got my a4 2014 and running a CTS intercooler and AWE exhaust on 20'' wheels. everything else stock for now other then cosmetics..
i just got back to back fill ups with over 600km on a tank which is better milage then what my chevy cruze was giving me :)

i will start to monitor the data, as i want a good ballpark before i tune in the near near future....

[Theiceman]

is that a v8 S4 ?

[Tanner]

DesiredCustoms - 2014 A4
merlinq21 - 2011 S4
mine - 2010 S4

So yes, it's easy to get 600+ km range on the 2.0T. Kinda miss that... uh, no not really :)

[Crucible35]

I have a 160km round trip commute to the office that I do 4 times a week.....live in Markham and office is in west Mississauga....99% 407. I drive about 40,000 kms per year and am very sensitive to my l/100kms. As mentioned above it's the winter gas most likely, I see my values increase from 7.5l/100kms to roughly 8.8l/100 on my 2015 2.0T A4. The other thing you may want to check is your tire pressures. They drop around now and can have a pretty significant affect. As well, I only use Shell 91 w/ 0 ethanol. If I fill up elsewhere on the very rare occasion, my l/100 kms drops.
I can usually get around 580 kms per tank in the summer but around 530 this time of year until spring.

[merlinq21]

V6

- - - Updated - - -

I have a 160km round trip commute to the office that I do 4 times a week.....live in Markham and office is in west Mississauga....99% 407. I drive about 40,000 kms per year and am very sensitive to my l/100kms. As mentioned above it's the winter gas most likely, I see my values increase from 7.5l/100kms to roughly 8.8l/100 on my 2015 2.0T A4. The other thing you may want to check is your tire pressures. They drop around now and can have a pretty significant affect. As well, I only use Shell 91 w/ 0 ethanol. If I fill up elsewhere on the very rare occasion, my l/100 kms drops.
I can usually get around 580 kms per tank in the summer but around 530 this time of year until spring.

Thanks for the feed back

[ahcow]

FWIW, I was lucky to get 11L/100KM on my old B8 S4. I used to get roughly 400km a tank (to red) with Shell 91, it was worse when I was using Esso 91.

[jschrauwen]

FWIW, I was lucky to get 11L/100KM on my old B8 S4. I used to get roughly 400km a tank (to red) with Shell 91, it was worse when I was using Esso 91.

Shell 91 has zero ethanol content whereas their 89 has 5% and their 87 has 10%. PetroCan 94 has up to 30% ethanol content. The FSI engines do not like ethanol additives. There's a few other gas companies that offer zero ethanol content.
I use this app on my phone when away from home area. http://www.pure-gas.org/

[merlinq21]

Shell 91 has zero ethanol content whereas their 89 has 5% and their 87 has 10%. PetroCan 94 has up to 30% ethanol content. The FSI engines do not like ethanol additives. There's a few other gas companies that offer zero ethanol content.
I use this app on my phone when away from home area. http://www.pure-gas.org/

You know you maybe on to something- I have been recently using 94 from petro can like the last 4 fill's before that I used three different shell stations - I wonder if the 30% ethanol is the issue. Going to run one more fill using Shell and see if that doesn't get me back some better results- good point and thanks

[merlinq21]

You know you maybe on to something- I have been recently using 94 from petro can like the last 4 fill's before that I used three different shell stations - I wonder if the 30% ethanol is the issue. Going to run one more fill using Shell and see if that doesn't get me back some better results- good point and thanks

note

Source- Shell Canada Website. I think we have found the issue- Thanks
11. Is Shell V-Power NiTRO+ premium gasoline safe for all vehicles?
Shell V-Power NiTRO+ is effective in all gasoline-powered engines found in conventional, modern and hybrid vehicles as well as motorcycles, snowmobiles, and leisure marine vehicles.
Shell V-Power NiTRO+ premium gasoline in Canada does not contain ethanol.

[jschrauwen]

You know you maybe on to something- I have been recently using 94 from petro can like the last 4 fill's before that I used three different shell stations - I wonder if the 30% ethanol is the issue. Going to run one more fill using Shell and see if that doesn't get me back some better results - good point and thanks

You're most welcome. It might not be the final solution, but it can't hurt.
The reason I found this out was this past summer I went to www.techmax.ca checking to see if my engine needed to be de-carboned using the walnut shell blasting process since the FSI engines are noted for encountering performance issues due to carbon build-up on the intake valves and valve area. The owner there, Atilla, mentioned to me that they tested the PetroCan 94 octane to have nearly 30% ethanol additive. I've been using that Petrocan 94 and the previous Sunoco 94 for almost 15 years on my high HP TT 300ZX believing it had a much much lower ethanol content as they advertised only ~ 10%.
If your engine hasn't been de-carboned, then perhaps that may be why you're beginning to see mileage issues. There's plenty of threads on the subject. There are various de-carboning processes but the most effective and long lasting is the walnut shell blasting process. It's been a common practice for FSI engined BMW's for years and the process has just migrated to the VW/Audi FSI engines. Perhaps something to think about after your gas type change. Here's a good video on the subject. I thoroughly believe the Italian tune-up process is a good occasional practice.

I like this guy - https://www.youtube.com/watch?v=RnhUJsZXzmg

[jschrauwen]

[ahcow]

Shell 91 has zero ethanol content whereas their 89 has 5% and their 87 has 10%. PetroCan 94 has up to 30% ethanol content. The FSI engines do not like ethanol additives. There's a few other gas companies that offer zero ethanol content.
I use this app on my phone when away from home area. http://www.pure-gas.org/

Yeah, I made the switch to Shell after a discussion on that topic on this very forum. I even tracked my mileage over 6 months (3 with Esso then 3 with Shell), I was seeing a 10% difference.

[jschrauwen]

Yeah, I made the switch to Shell after a discussion on that topic on this very forum. I even tracked my mileage over 6 months (3 with Esso then 3 with Shell), I was seeing a 10% difference.

That's pretty good numbers. I never took the time to evaluate the change-over. My discussions with Atilla of Techmax in Mississauga was convincing enough. He knows his stuff and he runs a top tier shop IMO.

[merlinq21]

You're most welcome. It might not be the final solution, but it can't hurt.
The reason I found this out was this past summer I went to www.techmax.ca checking to see if my engine needed to be de-carboned using the walnut shell blasting process since the FSI engines are noted for encountering performance issues due to carbon build-up on the intake valves and valve area. The owner there, Atilla, mentioned to me that they tested the PetroCan 94 octane to have nearly 30% ethanol additive. I've been using that Petrocan 94 and the previous Sunoco 94 for almost 15 years on my high HP TT 300ZX believing it had a much much lower ethanol content as they advertised only ~ 10%.
If your engine hasn't been de-carboned, then perhaps that may be why you're beginning to see mileage issues. There's plenty of threads on the subject. There are various de-carboning processes but the most effective and long lasting is the walnut shell blasting process. It's been a common practice for FSI engined BMW's for years and the process has just migrated to the VW/Audi FSI engines. Perhaps something to think about after your gas type change. Here's a good video on the subject. I thoroughly believe the Italian tune-up process is a good occasional practice.

I like this guy - https://www.youtube.com/watch?v=RnhUJsZXzmg

Thanks again; my issue is that if the fuel switch does not fix or improve the situation what will Audi do about it? Car was in yesterday and they did not find any error codes. To prove that I am not abusing the car in terms of driver behavior causing fuel consumption- they want to let the tech take my car home and drive it to home and back to work. They will define what the issue is from the test. I agree with the process and I hope they find they need to do more investigation.

I would be surprised if Audi would own up to carbon fouling and at their cost de carbon the intakes?

We will have to wait and see what they come up with - appointment is next Thur so hopefully I will have something to report in two weeks!