xfirechief

Anyone who purchased an A 6 TDI have second thoughts that they should have stuck with the gas engine after some time has passed?
If so why?

I should mention we drive around 15K per year mostly rural area. 75/25

audi40

Nope. I had a 2010 3.0T before so I know how the engines compare - I've had my TDI for 3+ months and 4k miles, and don't think I'd ever go back to a gas engine.

in2dwww

I've had a VW 2010 Jetta TDI and a 2013 Passat TDI. I now have a MB BlueTec and an A6 TDI on order. Once you go diesel, you never go back. My only regret was selling the Jetta TDI for an A4 gasser. The Passat was a regret because it was a badly made car. The MB is a locomotive.

qqq1970

I had an offer I can't resist but otherwise I'd have waited for the TDI. I drove diesels when I travelled in Europe and it is a sensible choice. Unlike hybrid, diesel is a mature and proven technology. While pick up from standstill is slower than the 3.0T, the TDI's low end torque is very handy in passing traffic. Most of us seldom drive to the redline so the nameplate peak 310 hp at 5500 rpm is irrelevant in most driving situations. If we look at 1500-2500 rpm used in normal driving situations, we harness an estimated 244-314 lb-ft of torque and 85-150 hp respectively from the 3.0T. For the 3.0TDI at same rev range, the full 428 lb-ft of torque is available and produces power between 105-180 hp respectively. So we get more useable power from TDI and better fuel economy than 3.0T in normal driving rev range.

In Europe 70% of cars sold is diesel and in UK the only gas A6 sold is the 2.0T hybrid, S6 and RS6 the rest is all diesel. Europe sells an A6 3.0T biturbo diesel that has 313 hp, a monstrous 479 lb-ft of torque that tops a Ferrari 599 and 0-62 mph that beats the 3.0T by 0.2s according to EU figures. The performance gap between gas and diesel is more apparent beyond 62 mph. Someone posts on YouTube a 3.0T takes 24s to hit 125 mph and 46s to hit 155 mph. A 3.0 biturbo diesel with only 3 hp advantage over 3.0T achieves that in 20s and 38s respectively because it beats 3.0T in hp across the rev range. It is no wonder the business case for gas engine in Europe is weak when it doesn't beat the diesel in performance nor mileage. Where I live, diesel costs the same as regular gas, so you get double benefits from better mileage and lower pump price.

Are there shortcomings in diesels? Yes there are a few. The heavier diesel engine means weight distribution is more biased towards the front at 59/41, compared to 55/45 for the 3.0T and there is more understeer. Upfront cost is higher (same in Europe) so it takes a couple of years to get the payback in fuel savings. If you intend to own the car long term diesels make a lot of sense, if you lease or own less than 4 years then diesel is not for you. Diesel crankcase is more sturdy to withstand the higher compression ratio and hence usually lasts longer than gas, but most of us don't own the car more than 15 years.

All that said, I think Audi TDI pricing is wrong. In Europe the 3.0TDI we get is the diesel counterpart to our 2.0T gas model so the $2,400 diesel premium should be over the 2.0T not 3.0T (alright, to be fair the 245 hp TDI performance is better than 2.0T so maybe another grand or two over 2.0T. Europe has another de-tuned 3.0TDI that generates 204 hp that is a real counterpart to the 2.0T). In Europe the 245 hp TDI is priced below 3.0T so don't know why it is the reverse here. Now if they bring the 3.0 biturbo TDI monster then it would make sense to tag a $2,400 premium over 3.0T. As it stands it is hard to convince customers to go with TDI that costs more than 3.0T but weaker performance, at least on paper. As I said above, practically the useable performance of TDI is not worse than 3.0T.

I look forward to the day when electric hybrid is tagged to diesel engines. That would be marriage in heaven.

Thanks for bearing with my long blurb.

qqq1970

MB diesels, while not high performance, are reputed for durability. From time to time they issue press release of drivers who log one million km or 625,000 miles on the diesel.

DasA6

I cannot remember where I saw this but someone said that diesel engines are taxed more than petrol engines as an import to the US. Perhaps it is not true but my quick Google search found the US to have some very low diesel import tax.

Also, did you see where MB has created a diesel-electric E-class?


As to the OP,

It is a true phrase, "Once you go diesel, you never go back." I could not imagine driving a gasoline engine as a regular everyday car. Granted, performance wise the gas is better, but if you are working M-F and drive some distance, you cannot go wrong with diesel. I get consistent 30mpg in the city and city only. Highway it is about 38. Oh and with the torque and quattro? Dream come true.

irenesbob

Do any of the diesel owners find it difficult to find service stations that carry diesel fuel? I never owned a diesel car, but had diesels in two sailboats I owned. I found them very reliable in the boats, so I have no reason to dislike them beyond the idea that they seem to add weight to a vehicle. In my area in suburban NYC I seldom see diesel for sale, although maybe that is because I am not looking for it for my car. The NYS Thruway service areas all carry it I think, so that’s plus. Just asking.

qqq1970

I don't know about import duties. My understanding is diesel engine has higher production cost. Diesel engine costs more in Europe and there is no import duties issue.

Alas, Mercedes diesel electric hybrid is not available stateside.

audi40

I think you're referring to the Federal fuel tax which is .06 more per gallon for diesel vs gas.

miwung

I just picked up a '14 TDI. I absolutely love it. I've been averaging 28 mpg over the first 800 miles, most of which is in stop and go traffic (the start/stop works great). I'm a performance junky (traded in a vette z06) so I don't like the fact that there aren't many upgrades you can do except APR flash (can't complain its a big jump in power for money). I can't comment about not having access to diesel. In NJ you can find it in most places.