Like the title says I’m considering buying a used 2014-2016 Audi A6 with the TDI diesel engine.  I want something nice to drive thats fuel efficient. The diesel is a plus since we have bulk on road diesel tanks and thats what pretty much all our other vehicles are. If I decide to buy one I’m probably going to trade in my 2014 STI sedan on it that only has 10k miles on it. I know VW had the buy back with TDI’s but I’m not sure how that effects the Audi’s or how it would effect me. I live in IL and we don’t have any emissions testing in my county. Anybody have experience with these?

I would keep considering it, indefinitely. Audi is not a Toyota from a reliability standpoint.

The wisest decision about cars I ever made was to NOT buy an Audi A6.

Never owned an A6 but we had an A8 for a bit.  I genuinely think you would have to go to a Bentley or something comparable to out do it in terms of luxury.  The problem is the engineering.  So much gets crammed in that when things go wrong the simple part is crazy expensive to fix.  For example, the thermostat started to stick and the engine would start to overheat.  I think it was like a $20 part but because of where it was it ended up being a $1,000 repair.  So, if you get one certified that has warranty, you will be fine.  Otherwise, just assume it is going to cost you a few grand at a minimum to keep up every year.

As for the engine and emissions, I can't say.  I just thought that i would share my experience with the brand.  To be fair, this is going back 10 years so things could be different now but it has kept me away from Audi.

Solid drivetrain but the rest of the car will nickle and dime you.

Pretty sure Audi means "boat" in German. Bust Out Another Thousand.   Seriously, I've been around collision repair for 20 years and everything is expensive to work on, you wait for the part forever, and in the last several years there is always some electronic module not talking to another module.  Audi's answer is always to replace modules until the problem goes away.   Good luck!

I would never own a German car out of warranty.

I did once, never again.

This here.

I drive a VW, but won't once the warranty is up.

I daily drive a EPL Stage 2 2012 A6 3.0T, VERY happy with it.

So much so we bought the wife a 2013 Q5 3.0T.

Put a tune on the TDI and enjoy it.

Thanks for all the replies. I really like the car but am afraid it’s going to be something that’s going to nickel and dime me like a lot of you guys are saying. I’m still considering it but am definitely going to keep looking and see what else is out there.

I considered a used A6, 535i, and E350 a couple months ago but the German $ upkeep scared me away.  I plan on keeping this car for awhile and don't want to pay for extended warranties so I stuck with Toyota and got a 2015 gs350.  Very happy with it so far and feel much more at ease with long term reliability.

I have not owned an Audi TDI but had a 96 and 06 Jetta TDI and now my commuter is a 15 Golf TDI. I've put just under 1 million miles on my TDIs.

If the Audi is anything like the VW the engine will outlast the rest of the car. I turn my own wrenches, follow the maintenance schedule and never had one of my TDI's leave me stranded.

I'd you buy it, idparts.com is a good source for OEM filters and such. Check malone tuning for ecu needs and I recommend rawtek I'd you decide to loose the emissions crap

Look at a use Hyundai Equus.  Less than $20k with a lot of luxury and a solid V8.  I've never owned Huyndai, but I wouldn't think that the maintenance is going to cost what an Audi costs and the Equus is more A8 than A6.  They were $70k new....some of them are $10k and $12k now.  I don't like cars, but if I was in the market I would definitely be test driving them.  Seems like a lot of vehicle for the money

Here is one pretty clean example

https://www.autotrader.com/cars-for-sale/vehicledetails.xhtml?listingId=502378308&zip=66221&referrer=%2Fcars-for-sale%2Fsearchresults.xhtml%3Fzip%3D66221%26startYear%3D1981%26sortBy%3DderivedpriceASC%26incremental%3Dall%26firstRecord%3D0%26marketExtension%3Don%26endYear%3D2019%26modelCodeList%3DEQUUS%26makeCodeList%3DHYUND%26searchRadius%3D0%26trimCodeList%3DEQUUS%257CUltimate&startYear=1981&numRecords=25&firstRecord=0&endYear=2019&modelCodeList=EQUUS&makeCodeList=HYUND&searchRadius=0&makeCode1=HYUND&modelCode1=EQUUS&clickType=listing