Up in a puff of smoke

I’d like to know the pros and cons of owning a diesel. I am looking at a 2004 VW Jetta TDi diesel (yes, I know about the Jetta jokes - my daughter totaled two of ‘em), and I know diesel fuel is more expensive, but at 36 miles/gallon, is it a good investment (e.g. don’t have to worry about spark plugs). And I do know it has a smokin’ habit. Just like to know if it would be a good investment. Thanks

Diesels get better mileage and have more torque than gasoline engines. If you like the car for it’s comforts and looks, well I guess it might be the car for you. Cars are never good investments, but if you like this one then buy it. And don’t be overly comforted by the vehicle not having spark plugs, there are still plenty of things that can go bad.

A modern diesel shouldn’t be smoking-- if the one you’re looking at is, it’s got problems.

Maintenance usually costs a bit more on a diesel and repairs can be pricey, especially if you live somewhere without an independent mechanic that can work on these and you’re beholden to the dealer. The TDI engines are pretty reliable and can go for a very long time if they’re well maintained, but the rest of the cars suffer from the spotty VW reliability. I personally would not endeavor to own any VW unless I had a trusted VW specialist to inspect the car before purchase.

Just from a strict economics perspective, the TDI might be better than a gas Jetta if you do a lot of driving. But versus a more reliable gas vehicle, the TDI will almost certainly end up being more expensive.

I have a 2002 TDI and love it. I get a little better mileage than 36 mpg more like 45 mpg. I have about 90,000 miles and no problems. 36 mpg would be about right for a TDI with manual transmission.

I would suggest two things. First find out how many miles on it and if it is about 80-100,000 verify if the timing belt has been replaced yet. That is a bit expensive and I would guess it is about due on that car.

Next I would suggest stopping by the TDI Club web site. It has everything TDI there. It also has a list of respected TDI mechanics in almost any area of the US and Canada. There you should be able to find a local mechanic to check it out for you.

BTW under normal conditions, you should not see any smoke except on heavy acceleration and then there should not be too much. Modern diesels do not smoke normally.

A VW diesel is an expense, not an “investment”. If you drive over 10k miles a year it could pay off. If you drive less, the cost of fuel or maintenance will not outweigh the costs of depreciation, insurance, taxes, registration, etc. VW’s do not age well and their upkeep costs rise after five years – not the engine, but electrical systems, HVAC, etc. Also check out a MB E320 CDI – a very nice used car, but priced much higher than a VW.


I second the ‘cars are NEVER an investment’ philosophy. You can expect to get 43-47mpg average and between 580-630 miles per tank. So you can go much farther between fill-ups which is good because you might have to spend a lot of time looking for ‘gas’ stations that may or may not have a diesel pump. After a while though you’ll know which are your favorite places to fill-up. Also, if you travel far frequently some diesel pumps have an oversized nozzle for filling trucks. The Jetta TDI can take this nozzle but you have to fill the tank VERY slowly or the fuel will bubble and overflow. There’s a lot more to have to know and deal with in owning a ‘special’ engine. What you probably don’t know is that every 80k miles you have to change the timing belt on the TDI engine. If you don’t and it breaks the pistons will smash the valves and the engine is ruined. The timing belt job you can probably do yourself in a weekend if you do your own wrench work already and have the time. Otherwise it could cost $900-$1000. So unless you have a reliable source for and collect your own waste vegetable oil and make your own biodiesel, the TDI will most likely never ‘pay for itself’ in fuel savings.