Volkswagen Repair: Question?, throttle body injection, highway mileage

Question
Hello don. I have a question for you.

Is it normal for the Diesel engine to get loud  after a while? I have been test driving some golf's GLS TDI diesel, and some of the engines are louder than others? Is that commom? Should I be scared by that? Is it due to some kind of problem with the engine? What you you sugesst?

What does it mean when they talk about (HB)GLS TDI?
What do they mean (OBO)? 12,500 OBO?

Wich one in between 2000-2001 you considere to be more expensive as far as maintanace and repears wise?

If I was to compare this car to a honda let say. Wich one do you think would be a better invesment on the long run considering: relaiability, maintenance & repears expenses,fuel economy? etc,etc.

Thanks a lot.
Alberto.

Answer
Alberto, thank you for your question.  Diesel engine vehicles can be a real pain in many ways. One is fuel cost, diesel is typically a little higher that gasoline.  Also you can only use “Auto Diesel” which is different from the type that the “18 wheelers” use. Diesels by nature are noisy.  This is because they technically run at a constant RPM and flow is controlled by use of a governor.  Also they get louder with more fuel added during acceleration. Diesels on cars are usually more expensive to repair since there are fewer repair technicians per vehicle.  

(HB)GLS TDI? – HB is hatchback GLS is the model and TDI is Turbo Diesel Injection. (TBI is Throttle Body Injection)
OBO is Or Best Offer

Which year model is better depends on the type of driving done (stop and go traffic, high city or highway mileage), where you are at (as far as climate, the higher the average temperature the more cost in maintenance and the same with average lower temps).  

If you compare a Honda, Toyota, Nissan or VW (water cooled).  Probably the biggest difference is the resale value.  The first three I listed hold their value for about the first 4 years with an average mileage of about 20,000 miles a year but above that the resale value drops like a rock. Fuel economy has stabilized with most of the 4 to cylinder vehicles between 25 city and 32 hwy with some exceptions.  When it comes to buying used vehicles there will always be the problem of reliability.  That is because many people will trade off or sale a car they are tired of repairing, so that it will become someone else's problem.  That may sound a little cynical but that is just what I have seen over the years in the used car market.  There are great buys out there that are in outstanding shape and there are real Lemons too.
Hope this helps.