I don't know much about VW diesels, but my F350 diesel never has had so much as a hiccough. On the other hand, its mileage stinks.
When I ran on an ambulance crew, we ran modified Ford E350's van-styles with non-turbocharged diesels (1997 models). Those engines were bullet-proof and fairly economical (8-11mpg). When ran the crap out of them to cover a large area of rural Ohio (top speed aerodynamically limited to 111 mph). When I left, most had 170K miles with no probs (except for Unit 113, which some rookie totalled -- that was my favorite rig). The specialized Medic units they bought had the "new" at the time PowerStroke turbo-diesel. Lots more problems with those: turbos going out at 80-100K miles, valves broke in half, and various electrical problems. -- but they were quick (unfortunately governor-limited). Now all come with the Power-Stroke -- I guess the trick is to let the turbo cool down, but that's impossible when you run "hot" to the hospital and have to shut down under the canopy to prevent fumes. I miss those days...I want to drive a diesel again, but nothing reliable is available right now (unless I unload 60-large on a Mercedes E320D) -- yeah right.
2003 Jetta TDI - MFG recommended timing belt replacement interval: 105K. My electrical problems at 110K- 1. front speakers cut in and out at low volume (suspect a grounding connection somewhere, this happened with factory radio and aftermarket, cranking the volume takes care of it) 2. Ignition switch needs to be replaced, won't start in cold weather 3. Recall on brake light component. Only other problem has been coking at the junction of EGR, crankcase vent and starting air supply valve. Lift hood move actuator on butterfly, problem solved (VW fixed in 2004 model). Runs great, fun to drive, lifetime average fuel economy > 53mpg. Expecting 5-10% increase with more extensive coasting and pulse and glide. If only traffic would cooperate.
Which is not more expensive than a good synthetic you'd put in a gasser. Granted you'll have to change it a bit sooner than you would on a gasser, but it's not impossible to go on pretty impressive drain intervals.
2. The timing belt needs changed every 60,000 miles
There are 100k kits available to mk4 TDIs.
3. Consumer Reports rates it in the pooper for reliability
They can say whatever they want, but it never let me down. Sure they have some problems, but it's really just little annoyances. In my car I've had problems with poor lightbulb contacts, the handbrake switch, the cruise control switch, the wipers grease jamming up in the cold and the door latch jamming in the cold too. But nothing that contact cleaner and a generous dose of various lubes wasn't able to resolve.
The powertrain is rock solid. The car can take a lot of beating. Neglect no, but beating yes.
4. If you live in areas with harsh Winters, you have to add an anti-gel fluid to the fuel, and an engine block heater is almost mandatory.
I live in Quebec City and never plugged the TDI once this past winter (because I couldn't). It always started instantly after a good glow plug cycle.
If you live someplace where it gets cold enough for the fuel to gel, chances are there will be all the additives needed in the fuel. At least in the province of Quebec. I've never had my fuel gel in any diesel I've driven since I started driving.
I would never get it and here is why...
1. Jetta are not reliable, too many electrical problems.
2. Diesel is really expensive.
My experience is that the US-sold VW's assembled in Mexico are either SUPER, stone-stock reliable, or abysmally UN-reliable - it's a crapshoot, luck-of-the-draw thing, and there's nothing in between. My Dad's '00 Passat V6 4motion was bar none the most reliable car we've ever had, and through 5 years and over 60k miles the ONLY issue we had was the flimsy rear cupholder. No CEL's, no hiccups, nothing at all. Everything down to the brake pads were in good shape.
My Mom's '00 Beetle 1.8t on the other hand was a disaster...both window motors went out three times in the same five years, the hatch release solenoid failed, the passenger lock motor failed once, various interior trim pieces came loose, and vacuum hoses were mysteriously disintegrating.
Back to the topic though...a Jetta/Golf TDi was what I was originally looking for when I got my SVT Focus...shoulda gotten the VDub though. Even with diesel costing ~70-80 cents/gallon more here, I'd be ahead in fuel costs at 50mpg vs. 30 with the Focus.
'67 Mustang - out of commission after an accident
'00 Echo - DD
'11 Kia Rio - Wife's DD
'09 Harley Nightster - 48mpg and 1/4 miles in the 12's