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Sedans Volkswagen Jetta VW Jetta TDI
3757 messages, Last post on Dec 07, 2009 at 4:45 PM
You are in the Volkswagen Jetta Forum. Your Hosts are pat & karens
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I am looking to purchase a Jetta 2009 TDI and am trying to figure out what I should pay and which warranty I should buy for it. I will put nearly 30,000 miles per year on it so the standard warranty will blow out in a matter of a 1.25 years. I need this car to at least last me 100,000 to 160,000 miles (to cover the 5 year financing). Best warranty and cost/price from VW? Can't find much info on the official VW website. Thanks, Kris Arthur
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a civic diesel would get HUGE mpg: 140% or 150% of gasser civic's mpg. (comparing VW TDI with smaller/lighter gasser cars that get 37 mpg is not an apples-to-apples comparison.) Although I prefer VWs today, I civics and have owned 3, for ~200k miles total. (90 base/hatch, 92 EX, 93 LX) . the civics' highway mpg dropped from >40 to <30 when california RFG1 was introduced.  Yesterday I was conversing with an ancient pal who once had a CVCC engine disassembled on his kitchen table. The pistons were so tiny - they looked like they were from a RC aircraft. [edit: maybe i should say "fit" instead of "civic" in this post! today's civics are as large as accords were back when i owned civics - and the jetta is probably bigger than passat was back then!  ]
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Replying to: karthur1 (Jun 22, 2009 7:47 pm) Try looking up dealers in our Dealer Ratings & Reviews feature. Also you can ask others who are hanging out in our Volkswagen Jetta Prices Paid & Buying Experience discussion as well as the VW TDI Models Prices Paid & Buying Experience topic. Good luck - let us know how it goes. |
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Replying to: elias (Jun 23, 2009 3:06 am) "The density of petroleum diesel is about 0.85 kg/l (7.09 lbs/gallon(us)), about 18% more than petrol (gasoline), which has a density of about 0.72 kg/l (6.01 lbs/gallon(us)). When burnt, diesel typically releases about 38.6 MJ/l (138,700 BTU per US gallon), whereas gasoline releases 34.9 MJ/l (125,000 BTU per US gallon), 10% less[5] by energy density, but 45.41 MJ/kg and 48.47 MJ/kg, 6.7% more by specific energy. Diesel is generally simpler to refine from petroleum than gasoline. The price of diesel traditionally rises during colder months as demand for heating oil rises, which is refined in much the same way. Due to recent changes in fuel quality regulations, additional refining is required to remove sulfur which contributes to a sometimes higher cost. In many parts of the United States and throughout the UK and Australia[6] diesel may be higher priced than petrol.[7] Reasons for higher priced diesel include the shutdown of some refineries in the Gulf of Mexico, diversion of mass refining capacity to gasoline production, and a recent transfer to ultra-low sulfur diesel (ULSD), which causes infrastructural complications.[8] http://en.wikipedia.org/wiki/Diesel_fuel" The true measure of efficiency of a piston internal combustion engine is the so called brake specific fuel consumption (BSFC) which is weight of fuel consumed per unit time per unit power output. In English units this is lb / hp-h and in metric units this is g / kWh. An advantage of gasoline is that it is relatively higher in hydrogen than diesel fuel. Natural gas (methane CH4) is higher in hydrogen than gasoline. The lower the moleular weight of a saturated hydrocarbon the higher is the amount of hydrogen relative to carbon. The molecular formula of a saturated hydrocarbon is CnH(2n+2). So the ratio of number of H to number of C in a saturated hydrocarbon is 2 + 2/n. So the ratio is 4 H per C in methane n = 1, about 2.25 for gasoline n=8, and about 2.14 for diesel fuel n = 14. After all these effects are taken into account a modern TDI diesel is currently still significantly more efficient (lower BSFC) than a sequential multiport injected gasoline engine of the same power output, and diesel fuel is much less of a fire hazzard than gasoline in case of a spill. But it remains a question as to whether the efficiency advantage of a diesel is enough to pay for the significantly higher cost of the diesel engine, and potentially higher maintenance costs over the life of the engine, e.g. glow plugs, high pressure fuel injection system. When the next generation of gasoline engines comes out (turbocharged direct inject gasoline still spark ignition) the differences will no doubt be narrowed, but then the cost of the gasoline engines will rise relative to the diesel engines. |
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Replying to: jim314 (Jun 23, 2009 4:39 am)
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Replying to: elias (Jun 23, 2009 3:06 am) Indeed that is the utility of comparing apples to apples (like-models) . A Honda Civic diesel would overnight turn the already great economy car into a serious economy leader/king/queen for many MORE years to come. I think Ford/GM/Chyrsler would take the WC Fields line: go away boy, you are bothering me. Most folks understand the weight factor effects a (further) loss on mph. They might not know the rule of thumb (plus+/minus - : 1-2 mph per 100#'s) For example the weight difference between a 03 VW Jetta TDI and a 04 Honda Civic is 436 #'s (2950#'s 2514#'s) So a Civic getting 38-42 mpg (using the rule of thumb ) would now be 33.64 to 37.64 mpg vs a TDI of 48-52 mpg. This of course works vice versa also. (what mpg would the TDI get being -436 #'s lighter) Need another graphic? What do you think would be the difference in mpg would be with one person and 3 extra (normal weight) folks or 2 college football types (218#'s each)? |
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jim-pi*100 , thanks for your detailed and thought-provoking data & analysis. diesel is less expensive than gasoline *per gallon* in most of USA currently, and mpg is indeed a crucial factor for bottom-line for drivers. I think a metric like "miles per pound of fuel" is more important for rocketry & NASA, and less important for passenger vehicles. I don't anticipate fuel being sold per unit weight or with prices normalized to take density into account - and until/unless fuel is priced like that, I conclude that your initial point is simply not correct: the one about diesel advantage being falsely-high/misleading. There's no falsity here. The cost to own/operate "is what it is" no matter if we use non-standard units to do the comparison. (Shall we compare using the number of drachmas per joule, or cubits per gallon?) Buyers can always do the math given current fuel *per gallon* prices, and compare "true cost to own" in order to determine if the extra $200 or $1000 or $5000 cost for the diesel-engine is a likely "slamdunk" win for their situation. One possible optimizing strategy is to own two lower-cost vehicles instead of one big-$ vehicle. one gas, one diesel, driving each according to prices/conditions/needs and to minimize the price per cubit of driving.
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Bought my TDI almost 2 weeks ago. Dealer filled up the tank and computer shows I can still run another 200 miles. (for a grand total of almost 435 mles). My question is (and I'm sorry if this has been asked before) are there any differences between Shell, Amoco/BP, Exxon/Mobil .........? Is one better than the rest? Anything I should watch out for? Thanks
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Replying to: jim314 (Jun 23, 2009 4:39 am) Regardless of weight the most important issue is that you can about 40% farther on a gallon of diesel as compared to a gallon of gasoline. |
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Replying to: elias (Jun 23, 2009 5:58 am) If all you want is to calculate the cost of driving a certain distance today, then, of course, all you need is the fuel volume consumed per unit distance and the price per unit volume. But if you want to ponder the relative merits of gasoline and diesel engines in the larger scheme of the environment and the economy, then a scientific approach is needed. The environmental regulations in Europe and in the US used for setting taxation or regulation of carbon emissions recognize that diesel fuel contains as much as 15% more carbon per unit volume than gasoline. The calculations of carbon dioxide release per unit distance travelled (g/mi, g/km) are to multiply the mpg by one factor for gasoline and a higher one for diesel. A scientific approach is also more likely to lead to a correct understanding of what the future prices of these fuels will be. From a scientific point of view diesel fuel is currently underpriced compared to gasoline and we must expect this would change if market forces would set the prices. Why wouldn't diesel fuel and gasoline be priced equally per unit mass or per unit energy content? At retail you buy meat, bread, beans and tomatoes by weight, right? Demand and environmental cleanup charges by the government (not cost of production) are what sets prices in a market economy with proper government regulation of the common envoronment. Already the introduction of ULSD has increased the price of diesel, and for that reason some people who demand that they be supplied as much fuel as they want at a low price were outraged at the insistence on forced introduction of this less polluting diesel.
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