Here From TDIClub - looking to increase highway mpg

[dremd]

RH77 To answer your questions
Yes I do oil changes on the Golf. Rotella T Blue bottle (synthetic) works GREAT for 03 and older (ALH). it is $14 for 4 qarts at Wall-mart. Blue Rotella T is not aproved for the 04+ PD cars, but many people run it anyway. Approved oil is around $7 a quart so that makes it around $45 for a change. You have to bear in mind that oil changes are at 10,000 miles so that typically comes out cheaper (or similar) to a gasser (unless you go to the stealership)

My car had a Timing belt done JUST before I purchased it (was overdue). He used the PD Belt and tensioner, so that's good for another 100,000 miles. I'll change it myself if I keep the car that long.

If you are after MPG get an ALH, typically (real world) they get 5~10 mpg better than the PD. and UNDER NO CIRCUMSTANCES buy an auto, -10~15mpg.

As far as starting, running and driving these cars are rock reliable, now as far as widow clips, door switches, and factory radios are concerned, well lets just say YMMV.

TDI Club is a great site, my only complaint is that some members drill doom and gloom on others if they don't do things to a T how they think they should be done.

All and Alll I LOVE the TDI. I get significantly better milage than my Prius driving friends, burn Bio now and then, and paid about 1/3 what they did. (Not Prius bashing here, I'd love one of those also)

[metroschultz]

Diesel motors have been used for long haul trucking since mass production of long haul trucks. This is where i work every night. They used gas and diesel in the beginning but soon found operation cost of gas motors to be too costly. That said.
Most of the operations for maintenance on a passenger diesel are the same as a gas engine. And VW is one of the most user friendly for maintenance out there. Many of your routine ops. are so easy they can be done right in the driveway.
Many people shy away from the small diesels for fear of the unknown, also, the motors tend to get really dirty really fast. So if you have access to a pressure washer, and are not afraid to try something slightly to the left of what you are accustomed to, maintenance on your personal diesel is no more hassle than on your gas motor.
Basically a timing belt is a timing belt(yeah i know some are a little more difficult, they still all do the same job) and an oil change is an oil change.
OK i got really wordy this time, shutting up now. S.

[SmartMath]

On the little 0.8L turbo diesel of my Smart ForTwo. According to the scangauge, my turbo push between 8 to 12 psi at around 100 km/h!!! It vary according to load but over around those number. I was actually very surprised to see that high of a reading!!! But as you see... boost doesn't automatically = big fuel usage.

The boost on the smart is limited to around 17ish psi (1.2 bar) from the factory. And it is very easy to peg it there with the little go pedal.

[dremd]

I need to make a short vid to illustrate the sudden down turn of Economy in correlation to boost on my car. I have been in many vehicles which do get good milage under boost (F250 + Cummins), I am not doubting that it can be done, I'm just saying that for some reason (fuel map??) MY milage does decrease significantly under boost.

[SVOboy]

You could always take away the boost by removing the spring in the wastegate.

[dremd]

Originally Posted by SVOboy

You could always take away the boost by removing the spring in the wastegate.

No wastegate on the vnt15. VGT

That works on the supra, no problem, just apply pressure to the wastegate actuator. Crazy loud (divorced downpipe) however it is not an option on the VeeDub.

Most Likely the TDI would just smoke without boost at that load without positive pressure anyway.

[dremd]

Just wanted to let you guys know that the reason why the aero mods haven't started yet is because my time has been going in to BioDiesel which appears to be a lower hanging fruit at the moment.

[tputus]

Maybe it's not the boost but EGR? On a gasser EGR reduces pumping losses
but on a diesel it slows down combustion, reduces peak temperatures (and thus NOx), makes BSFC worse. That is the reason heavy duty trucks in Europe use urea instead (AdBlue). That way truck manufacturers don't have to trade fuel efficiency, particulate emissions, power density, reliability against NOx. Making AdBlue has energy costs too, but those are not taxed so that's what we get.
Back to topic: listen for a hissing sound when the egr gate is opened. I think driving either with just a tad of boost but EGR closed or full throttle (EGR closed again by computer) is best. EGR systems in general are not reliable as you may already know so it is possible you have a faulty EGR valve?