Q5 TDI vs 3.0 TFSI Question
 

I'm thinking about purchasing a new 2014 Q5, but I haven't decided yet between the TDI or the 3.0 TFSI engine.

I wouldn't mind the TDI but my typical driving habits might change my mind on this. In a typical week during the summer I'll usually drive around 5-10 kilometres one way in the morning and then again in the evening each day (not very far). This is city driving only. The weekends in the summer typically involve highway driving for at least a couple of hundred kilometres. It could be much more if we go away on vacation.

In the fall/winter/spring, however, the driving is usually the same 5-10 kilometres in the morning/evening daily but only 50-80 kilometres of more city driving on the weekend (running around town, lots of driving for 10-15 minutes then stopping, repeat). Not much (if any) highway driving at all.

The concern I have is regarding the DPF (diesel particulate filter). From what I've read the DPF usually needs to recharge to burn off the particulates in filter, but that would typically be done once you reach the proper temperatures and then keep it there for an extended period of time (normally highway driving). During this time of year I could end up going for weeks without getting in any highway miles. If I had time, I could take it for a spin on the highway, but that would start to negate the benefits of TDI increased fuel mileage.

I'm wondering, based on my driving habits, if I would be better off getting the 3.0 TFSI and not having to worry about the potential DPF issues?

I have read where this is becoming a concern for quite a few people over in Europe where, due to their long periods of short distance driving only, the DPF is becoming clogged and requires replacing much sooner than would be expected if their vehicles were driven longer distances.

I would typically drive around 15-20,00 kilometres per year, and anticipate keeping the vehicle for the next 7-8 years.

Any comments/suggestions would be greatly appreciated.

Stephen

Totally different vehicle but I know of a Chevy Truck Duramax diesel that went into limp mode for the very reason you describe. Based on that, your concern may be valid.

If I'm not mistaken the Audi TDI actually has a regenerative function that burns off the particulate filter when it needs to. It can run when the car is turned off and has its own burner within it.

My Golf TDI works like that. Very disconcerting the first time it happened.

Could well work the same in other VAG vehicles.

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Video explaining the new 2014 TDI Engine:

Skip to 12min and 33seconds to learn about the DPF and Burn off:

Is there a way to embed the video to start at a particular time?

It does have regenerative...what happens if it gets parked mid cycle?
 

It has regenerative to burn off the soot--both on the road passively but then actively if the system senses the soot filter is clogging up. Since coming to understand this, I've wondered what would happen if it activates shortly before entering a closed space like a home garage. The once in a while sound effects of the cycling of the rear brakes on shutdown to adjust is one thing. But to have effectively something akin to a self cleaning oven cycle running autonomously that could end up mid cycle in a garage seems like it could be an occasional weird surprise.

From what I remember reading there is 2 different types of regeneration for the DPF, active and passive. In the passive mode the particles in the DPF are burned off when the operating temperature is high enough through normal driving (highway driving for 20-30 minutes after everything is at normal operating temps). In my case this probably wouldn't happen very often in most winter months.

The second type is active regeneration (which is what Telate is referring to). From what I read it actually tries to heat up the exhaust gases faster to heat up the DPF to burn off the particles when passive regeneration isn't happening. But even with active regeneration it still takes around 10 minutes. If you turn the vehicle off beforehand it won't complete the cycle and will try and complete it the next time you run the engine.I'm not sure if active regeneration happens as soon as you start the vehicle or if ithas to wait for a few minutes before attempting it.

Bear in mind this is what I've been reading online to try and gather some information.

On the myturbodiesel.com website they mentioned the following:
"European TDI brochures include the warning: "Please note, driving conditions within inner-cities and the Channel Islands may not provide optimum conditions for the use of DPF technology. Therefore, it is advised that you consider this before ordering your vehicle with DPF". This note isn't in North American brochures. The Channel Islands are about 5 miles long so my interpretation of VW's warning is that being restricted to 4-5 mile trips may cause a malfunction due to the DPF not being able to warm up sufficiently."

Interesting there isn't anything mentioned on the North American brochures since I'm sure we've had the DPF for a few years now. Maybe most people who buy the TDI's here don't do a of short trips only. Or maybe the technology has gotten better since then.

Unfortunately I can't find an owners manual online for the Q5 TDI to see if anything is mentioned in there about not taking short trips.

I Think 3.0 TFSI is better than 3.0 TDI based on your driving style in Cagary, Canada.

I haven't checked TDI pricing vs 3.0t pricing, but if there is any additional cost to the TDI there may be no overall cost benefit to owning the diesel given your low kms, let alone the possible drawbacks you've outlined. As for power/performance, I call it a wash between the two engines.

I took both the 3.0T and the TDI for a test drive last Saturday. The 3.0T is quicker form a standing start but if you had both of them around 20 kph and floored them both, it would be close. The TDI sucks you back in your seat on acceleration. Both vehicles were very smooth.

In talking with the dealer about the whole TDI/DPF issue, his recommendation as well would be to go wih the gas engine vs the TDI.I don't think he was biased since they had a pile of diesels in their lot to sell but not a single 3.0T. From what he said the 3.0T are hardest to find and get.

Now it is just a matter of seeing if they will come down much on the price. From what I've heard here in Calgary they don't really budge from the asking price, but will throw in extras. I'd rather just have the price lowered.

On another note, the B&O sound system is really good in these vehicles. The TDI had the basic stereo and the 3.0T had the B&O. It's just a shame that up here if you want the B&O you have to order the $4,500 Technik level just to get the option of paying another $1,000 for the B&O. Why they don't offer the B&O in the Progressiv as an option is weird.