Review: 2009 Volkswagen Jetta TDI
by John Neff on Feb 9th 2009 at 11:56AM 
2009 Volkswagen Jetta TDI – Click above for high-res image gallery
The car as we know it is being redefined. Hybrids have reintroduced electrons to the driving experience, and the rumble, shake and shimmy of the internal combustion engine is being muffled and, in some cases, even silenced by cars like the Toyota Prius, 2011 Chevy Volt and Tesla Roadster.
For us to continue harnessing the energy of combustion under our hoods, we need to go much further on a gallon of fuel. Enter Volkswagen and the diesel-powered passenger cars it's been selling in the U.S. since the late '70s, the latest of which is the 2009 Jetta TDI. Follow the jump to find out how VW's newest diesel fares against the electrified future of the automobile.
Gallery: Review: 2009 Volkswagen Jetta TDI
Photos copyright ©2009 John Neff / Weblogs, Inc.
Most U.S. customers have largely ignored VW diesels. Early examples had their quirks, including an engine rattle that sounded like a Peterbilt and the propensity to puff out black smoke like a coal miner. Still, they could go twice as far on a tank of diesel compared to gas-powered cars and their engines lasted for hundreds of thousands of miles. A cult following has kept them going and many have been converted to run on vegetable oil and other bio-fuel blends.
It will be years before we know if the new 2.0-liter four-cylinder turbocharged diesel engine powering the Jetta TDI is as bulletproof as its predecessors, but we can tell you that its fuel efficiency is as impressive as ever. The EPA has rated the car at 30 miles-per-gallon in the city and 41 mpg on the highway. VW felt the EPA test cycle wasn't accurate and hired an independent company called AMCI to run more real world tests that yielded even better results: 38 mpg city/ 44 mpg highway.
We had the opportunity to take our TDI tester, which was *ahem* obviously provided by BOSCH, on a trip from Cleveland to Pittsburgh. We were specifically curious to find out if achieving similar highway fuel economy numbers as the EPA and AMCI required a hypermiler's touch, or if our lead-infused feet could manage equally respectable numbers. Long story short: Our best average fuel economy was 46.1 mpg on the highway.
The current fuel economy champ in the U.S. is the Toyota Prius, which the EPA rates at 48 mpg city/45 mpg highway. What makes the Jetta TDI so impressive is that it doesn't require a complex hybrid drivetrain to achieve similar results. The straightforward design of Rudolph Diesel's engine and an interstate, highway or autobahn is all that's required. In fact, the Jetta TDI doesn't even require a cross-country trip to show its stuff. Hop on the highway and within minutes the trip information display will report an average of 40+ mpg. Though high-speed cruising is when this powertrain is most efficient, we also achieved results in the mid to high 30-mpg range while running errands around town.
We didn't resort to drafting semis or cruising at insufferably slow speeds, either. Our average cruising speed was around 65 mph, and the only trick we pulled was shifting into Neutral down steep grades to keep some of the momentum that engine friction would have sapped away. The simple average mpg readout in the trip computer display was all it took to get us hooked on trying to improve our efficiency.
Most Americans have never driven a diesel-powered vehicle, let alone compared one with a gas-powered competitor. We have and can tell you that the experience of driving a diesel is markedly different. Aside from being less fuel efficient, gas-powered four-cylinder engines have to work much harder to keep you cruising. They're often described as loud and "buzzy" because highway speeds require most to turn over at a rate of 3,000 rpm or more.
Volkswagen's new 2.0-liter turbodiesel, which was named one of Ward's Auto's Top 10 Engines of 2009, runs at just 1,800 rpm while cruising between 65 and 70 mph, so the Jetta TDI feels and sounds more like a car powered by a large, unencumbered V6. It's relaxed and anything but buzzy, accomplishing all of its work below a 4,500 rpm redline that ensures things never get hectic underhood. Also gone is the knock, clatter and clang characteristic of past diesels. The Jetta TDI is as quiet as a luxury car on the highway, and though the diesel can be heard while idling, the entire car is eerily vibration free while sitting at a stop light.
The '09 model is also significantly quicker than VW diesels of the past, taking a tick above eight seconds to reach 60 mph, but even that metric doesn't tell the whole story. Though rated at only 140 horsepower, the engine's 236 lb-ft of torque means there's power aplenty. While off-the-line acceleration won't scare any sports cars, the Jetta TDI exhibits an effortless thrust when the right pedal is pushed. Whiplash inducing it's not, but the wave of power this little engine produces while underway is remarkable for its size.
Diesel engines have always been known their stump-pulling power, but they also have a reputation for being dirtier than gas engines. This became an issue a few years ago when California and the Environmental Protection Agency enacted their corresponding LEV II and Tier 2 Bin 5 emissions standards that erased the distinction between diesel- and gas-powered engines.
The modern diesel engine required major work to meet these new standards and gain access to markets in all 50 states, and most companies resorted to injecting a urea-based solution ahead of the catalytic converter that specifically targets the most harmful particulates like Nitrogen oxides (NOx). This solution, so to speak, was less than ideal because of the extra effort required to refill the solution at regular intervals. Volkswagen, in partnership with BOSCH, has developed a diesel engine for the Jetta TDI that's clean enough for sale in all 50 states without the use of a urea-based exhaust treatment system.
The trick is the use of a particulate filter in the exhaust system that requires zero maintenance from the driver. When the filter becomes full of harmful particulates, the engine's ECU will adjust the air/fuel ratio to raise exhaust temperatures high enough to burn them off. This process occurs every 300-500 miles and is all but transparent to the driver. Since raising exhaust temperatures requires a richer air/fuel ratio Fuel economy suffers slightly during this process, which we experienced on our way to Pittsburgh when we noticed a sudden but temporary 1.5-2 mpg drop in fuel economy.
The Jetta TDI isn't all about saving us from buying a few extra barrels of foreign oil. It also happens to be a dynamic small car with above average moves. The independent suspension with 16-inch alloys at all four corners exhibits typical German tightness with a solid ride that's not easily shaken. The standard, gas-powered Jetta has always been ahead of the economy car curve in this regard, and the TDI version is that much more so compared to cars like the Prius with its myopic focus on fuel efficiency at the expense of driving pleasure.
Another thing you're not going to get with a hybrid is transmission choices since most use a highly efficient CVT, or continuously variable transmission. Volkswagen offers two transmissions for the Jetta TDI: a good, old six-speed manual and six-speed DSG dual-clutch transmission with manual and Sport modes. Operating the row-your-own version is an above average experience for a small car, but the DSG is where you want to put your money. The latter will act like an everyday automatic if left to its own devices, but slip the stick over a notch and you're in control of precise shifts that occur quicker than you could make them yourself. VW deserves a double ding, however, for the lack of steering wheel-mounted paddle shifters and arranging the DSG's manual control as forward for up-shifts and backward for down-shifts.
There's still more decisions to make if you're considering the Jetta TDI, as VW also offers a SportWagen model in addition to the sedan. The four-door offers a 16-cubic-foot trunk, but the wagon goes above and beyond with 33 cu ft behind the rear seats and 67 when they're folded. While you may pay a small mpg penalty for the extra weight, the SportWagen TDI offers an unrivaled combination of utility and fuel efficiency in the marketplace. The EPA, however, reports the same results for SportWagen TDI as the Jetta TDI sedan: 30 mpg city/41 mpg highway.
For most, the decision to buy an exceptionally fuel efficient car like the Jetta TDI has less to do with making Mother Earth your BFF than saving money on fuel costs. The irony is that breaking the 40-mpg barrier adds a significant price premium to the up front cost of a car. In the case of the Jetta, the TDI version carries an MSRP of $22,270 versus the comparably equipped, gas-powered SE model that starts at $20,095. You may have noticed, however, that the Jetta TDI also qualifies for a $1,300 tax credit that more than halves the up front price premium, though that will only apply for the first 60,000 units VW sells.
Then there's the cost of diesel fuel to consider. When we topped of our tank, the price of diesel at our local station was $3.70/gallon versus $2.60/gallon for regular unleaded. Prices for both fuels have fallen since then, but the national average for diesel is still higher at $2.24/gallon versus $1.89/gallon. You will, however, go much farther on a tank full of diesel. Using EPA numbers, a Jetta TDI with 14.5 gallons of diesel could conservatively travel 595 miles on the highway before hitting empty, whereas our real world experience of over 46.1 mpg equates to 668 miles. A manual-equipped Jetta SE using a gas-powered 2.5-liter five-cylinder engine with 14.5 gallons of regular unleaded would stop on the highway after 450 miles.
The Jetta TDI has won us over because it offers what no hybrid on the market does: flexibility. Not only does it come in sedan or wagon form with your choice of transmission, but its mere existence represents an alternative for car shoppers who want fuel efficiency, but not at the expense of enjoying the car they drive.
Volkswagen will add to this equation by offering a TDI version of its Rabbit hatchback this fall using the same 2.0-liter TDI engine, and may also sell a street version of the Jetta TDI race cars that compete in the Jetta TDI Cup. There's also the Touareg V6 TDI on sale now and the Aud A3 TDI arriving later this year for those who need more utility or want extra luxury.
The 2009 Volkswagen Jetta TDI is a push back against our future of electrified motoring, and VW/Audi will soon be offering more diesel-powered models in the U.S. than ever before. A world that has silenced the sound of pistons pumping is not preordained, and the Jetta TDI proves that there is a way to meet stricter fuel economy standards without sapping the fun of driving from point A to point B with as many turns in between as possible.
Gallery: Review: 2009 Volkswagen Jetta TDI
Photos copyright ©2009 John Neff / Weblogs, Inc.
Reader Comments (Page 1 of 3)
zamafir 12:10PM (2/09/2009)
Great review, I've yet to find a more frugal and fun car for highway cruises... just curious though, how much is GM paying for little quips like this:
"Toyota Prius, 2011 Chevy Volt... Tesla". Last I checked, the Volt hasn't been driven i production form and isn't on sale, and that 2011 date is the result of continued back pedaling on GM's part. Isn't it a bit early to mention it matter of fact as heralding electric driving when the car's not out yet, and won't be out for a year or so at the earliest?
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220v 12:31PM (2/09/2009)
"Since raising exhaust temperatures requires a richer air/fuel ratio, fuel economy will suffer slightly during this process."
You may want to verify this, John. Air / fuel mixtures lower than stoichiometric (rich) tend to lower exhaust gas temperatures because there is unburnt fuel to absorb the heat of combustion. Leaning out the A/F Ratio will increase exhaust temperatures.
Any forced induction experts want to chime in on this?
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why not the LS2LS7? 12:37PM (2/09/2009)
It does enrich the mixture. The mistake is in the phrasing of the sentence.
Higher exhaust temps aren't needed to burn this off, higher catalyst temps are needed. The catalyst heats up by oxidizing unburned fuel in the exhaust. It cannot do this if there is no unburned fuel in the exhaust, which is what happens if the engine runs at stoichiometric or leaner. And Diesels usually run leaner than stiochiometric at highway speeds because they don't have a throttle plate to close and reduce the air to match the fuel (which is part of why the have such good highway economy).
So in order to burn off these residues, the computer puts extra fuel in the car, which isn't completely burned off and goes to the catalytic converter where it reacts and heats up the catalyst, allowing the deposits to be burned off.
HCCI cars have the same issues, with the catalysts cooling off due to lean burning. They also have similar advantages on the highway over conventional gas vehicles (and the same problems with excess NOx production as Diesels).
why not the LS2LS7? 12:32PM (2/09/2009)
A couple things. First of all, we need to go farther on a barrel of oil, as such the energy content of the fuel itself must be taken into account. This wipes away 15% of Diesel's advantage.
Second of all, the idea that the clatter and such is gone is RIDICULOUS. Yes, these are much quieter than before, there's no doubt. But when I was walking from my car into work the other day, there was a new Jetta near the door (parked across two handicap spots) letting people out. I could hear from 80 feet away it was making more clatter than usual (at idle!) and walking up to it confirmed it was a Diesel. There's no doubt these are more livable than before, but when you can tell what kind of fuel it is using before you can read the badges on the car, the clatter is not gone.
And finally, although not as complex as a hybrid, this vehicle is not straightforward like Diesel's design. 29,000psi injectors are not straightforward and nor is the addition of a turbocharger and intercooler. These are very complex engines, just not as complex as a hybrid.
And finally, on a more personal note, I still find it disgusting that companies are allowed to advertise fuel economy figures other than the EPA ones. If I competed against VW I'd retaliate by hiring someone to report more advantageous fuel figures for my vehicles too.
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Warren W. 5:15PM (2/09/2009)
Are you sure that the noisey Jetta that you saw was a 2009 model? The 2006 has the same sedan body style but uses the older PD engine. The only way to tell from the outside is to look at the TDI badge. The new ones have a blue I, whereas the letters on the older ones are all silver.
MBS 1:56PM (2/09/2009)
I find it far more disgusting that the hybrids' fuel efficiency is so incredibly inflated by the EPA test cycle. Those cars never would have gotten a market foot hold if it wasn't for the EPA's grossly overestimated numbers.
Why should a manufacturer be forced to market numbers that the EPA themselves have admitted to not being very good estimates?
why not the LS2LS7? 2:34PM (2/09/2009)
I don't know that EPA figures for hybrids are terribly inflated anymore. The Prius hasn't been rated at 60mpg for years.
The EPA has not admitted that Diesel figures are inaccurate. You really need to read the source material. Click on my name and look for some of my Diesel rants. This 18% figure only shows up in one place, and that is when comparing EPA figures to an internet poll. This same poll says high mpg gas cars (not hybrids, just gas cars with >30mpg) are also 10% underrated. These figures (either of them) are not corroborated by other figures that come from more controlled studies in the same report.
why not the LS2LS7? 2:40PM (2/09/2009)
Oh crap, I forgot to mention what is wrong with it.
The problem is that if every company uses different standards, customers have no way to really compare cars. Every car on the market will have the highest mpg in their class, simply because they'll pay someone to find a testing methodology that makes it so. This makes it possible to his poor mpg behind funky testing and removes any importance of companies actually competing on mpg and all clarity of what the relative efficiencies of vehicles are.
BobbyBud 3:16PM (2/09/2009)
Nice to see somebody actually point out how really complex the new diesels are. The last Ford F350 I tested, when I raised the hood I couldn't even find the block! At the same time, hybrids are getting a bit simpler (and the Prius actually has a very simple transmission and engine, and really low maintenance requirements). A Mercedes engineer I talked to went on for 10 minutes about how they build identically sized V6s, one diesel and one gas, and the Blue Tec is light years more complicated.
Great post.
Alex 3:46PM (2/09/2009)
Are you sure that was the new diesel? vw sold the new jetta with their older diesel in 2006-07, stopped in 08, and now came out for 09 with the new engine. I know the previous engine was quite loud, but if everybody says this engine is quiet then it most likely is, at least from the inside of the cabin.
why not the LS2LS7? 4:13PM (2/09/2009)
Alex, I didn't know the older engine was sold in the current body style. What you say is possible, although it is somewhat unlikely given that I live in California and I don't believe we had the previous Diesel Jetta.
I frankly assumed the car was not warmed up, as even current "quiet" Diesels cannot use the system of multiple bursts that make them quiet until they are warmed up. You can see the same effect when you drop the pedal, where the system also has to use continuous squirts even on a warm engine, and it brings the clatter right back. The fact that reviewers somehow overlook these things kind of shows that they're listening more with their hearts than with their ears when reporting on these cars.
will 7:40PM (2/09/2009)
LS2, Please explain your comment about how energy content of diesel fuel takes away 15% of the diesels advantage? Diesel fuel's energy content is higher than gas, which allows for greater efficiency in the high-compression diesel engine.
The '09 TDI is not silent but is a lot quieter than previous diesels, like my '98 Jetta TDI. I'm not sure (and neither are you apparently) what it was you were listening to, but chances are it wasn't an '09, as the previous PD TDI engine appeared in the Jetta TDI in '06 before VW's two year diesel hiatus. Those engines were louder due to the older injector technology used.
Regarding the engine's complexity, the diesel has evolved and has a more complex induction system than older engines, but is still a simpler powertrain than a hybrid. I'm not sure why you chose this point to harp on - the author was just using it as a comparison.
If you're disgusted that companies can advertise their own mileage figures, I guess you don't understand marketing. When the EPA revised its testing procedure for the '08 model year, hybrids took a hit because in real-world driving they didn't match their EPA testing figures. VW's diesels did. In fact, the new testing standard affected diesels the least. The TDI's 30/41 rating is laughable as many new TDI owners report high 30's in town and mid to high 40's on the highway (like John Neff wrote). The artificially low numbers didn't do much to help VW's case, so they went with an independant 3rd party for verification. By law, they still have to put the bs EPA numbers on the window sticker.
montoym 8:11PM (2/09/2009)
quote from LS2LS7: -
"I don't know that EPA figures for hybrids are terribly inflated anymore. The Prius hasn't been rated at 60mpg for years.
The EPA has not admitted that Diesel figures are inaccurate. You really need to read the source material. Click on my name and look for some of my Diesel rants. This 18% figure only shows up in one place, and that is when comparing EPA figures to an internet poll. This same poll says high mpg gas cars (not hybrids, just gas cars with >30mpg) are also 10% underrated. These figures (either of them) are not corroborated by other figures that come from more controlled studies in the same report." -
I agree that hybrid ratings are far more accurate now than they ever were before thanks to the EPA's '08 updates. However do you think hybrids would have become as popular if their accurate mileage had been advertised originally instead of the 60mpg claims they originally were listed with? That's what MBS was speaking of from my understanding.
Secondly, the Prius was rated at 60mpg as recently as the '07 model year. The new EPA guidelines didn't take effect until 2008. I guess 2yrs does qualify as "for years" but you make it sound as though it's been much more than the 2 years it actually has been.
In regards to your last section, I've posted about this same topic before in response to you.
That same source material also mentions that the YourMPG data has been used in the past to help determine inaccuracies in the EPA testing and was part of the reason the EPA updated their testing to what we have now. You'll note that the data for hybrids is now much more in line with what is reported on YourMPG because of the changes the EPA made in their testing.
So, obviously the EPA feels that the YourMPG data is valid and meaningful and it may help to rectify the diesel disadvantage that currently exists.
Basically, you definitely have a strong bias and double standard that is readily apparent in any post you make regarding diesels. I admit that I am biased as well, but I do not feel that I am inserting a double standard because of it.
For instance, you claim disgust with any company that utilizes 3rd party testing to refute EPA claims(of which VW is hardly the only culprit), yet you do not seem one bit concerned that the Prius(and other early hybrids) benefitted from inaccurate testing which greatly enhanced their mileage figures. EPA or not, the figures were a gross misrepresentation of the actual mileage that a buyer could expect. I'm fairly certain Toyota knew it as well but they obviously weren't going to say anything about it. Diesels are currently experiencing the same problem, but on the other end and I think that is far more damaging to VW than any damage that Toytota's sales took due to the Prius's inaccuracy.
why not the LS2LS7? 9:28PM (2/09/2009)
Will:
Listing figures is useless if everyone gets to make up their own figures. If companies are allowed to advertise figures other than the EPA ones, then they might as well not advertise EPA figures at all. Well, close to it.
What I'm saying about with efficiency is that efficiency is "energy put to work" divided by "energy put in". To change the bottom to "gallons of fuel put in" is to misstate what efficiency is. In a Diesel, when you put a gallon of fuel in, you are putting in 15% more energy than when you put a gallon of gas in. This must be accounted for in any real efficiency figure, in that the Diesel would have to go 15% further on a gallon of Diesel to even be as efficient as the gas car. Of course, Diesels usually go more than 15% further on a gallon of fuel than gas cars.
montoym:
If the EPA really figured that YourMPG was the way to go, wouldn't they have raised the fuel efficiency figures for high mpg gas cars (which were shown to be half as far off in that comparison as Diesels were)? But they did not.
To say that the EPA changing their figures endorses YourMPG is to completely ignore every point that doesn't favor Diesels. People are concentrating on a single data point in that report, somehow trying to say it is the one that defined the EPA's strategy.
Do I think hybrids would have been as popular with different mpg figures? Yes. In the timeframe that the old EPA figures were used, people were buying hybrids more for image than anything. Or they were buying them to get into carpool lanes during rush hour while driving alone. I don't feel that reduced EPA estimates would have impeded them from selling as well as they did, because people weren't buying the cars for the EPA estimates.
Last time you accused me of being anti-Diesel when I expressed a general skepticism of internet poll figures. This despite me pointing out that other figures (high MPG gas cars) also are a bit suspect. And if you want to box me as pro-hybrid, know I don't own a hybrid and my next car won't be a hybrid either. I do have friends who are very happy with their hybrids. Many even exceed the new EPA figures (but not the old ones), but I can tell you it is clearly because they have adopted techniques to increase their mpg, techniques which would apply to regular-old cars too. And finally, most are happy with their hybrids most of all because they can drive home at rush hour in the carpool lane.
As to me not bitching that other companies are advertising non-EPA figures, you couldn't be more wrong. There are very few companies that do so, but one is Ford with the Fusion hybrid, and I complained about that too. To be honest, I'm having trouble finding it with google, but I have more than once pleaded with autoblog to not be a party to helping ANY company promote non-EPA figures for any vehicle of any sort (hybrid, Diesel, horse-drawn, etc.)
Here's me bitching about it for Ford trucks:
http://www.autoblog.com/2009/01/26/video-mike-rowe-takes-on-dirty-job-of-comparing-full-size-picku/
I looked back two months and I cannot find my other posts about this. You'll just have to trust me on this. We need standardized testing so people can compare vehicles more accurately. Otherwise, companies will just all make their own standards which favor themselves.
gowen 8:50PM (2/13/2009)
camper - isn't the extra energy that diesel has per gallon more than taken into account with its price differential?
Mike P. 12:32PM (2/09/2009)
Diesels have certainly come a long way, and I'm glad to see more of them returning to North America.
...a side note though: are you quite sure it's legal to shift into neutral when going down a hill? It's illegal here in BC.
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Mike P. 12:34PM (2/09/2009)
In fact (I'm not sure if this applies only to standard transmissions) sometimes shifting into neutral can use more gas down a hill, because if the engine is being driven by the wheels the ECU can shut off gas to the engine, whereas in neutral gas has to be consumed to keep the engine idling.
...or so I've heard. =)
220v 12:52PM (2/09/2009)
Idling may use more fuel than if left in gear, but compression braking will sap way more momentum, which will consume significantly more fuel than that spent idling when the driver needs to accelerate again. The result of putting into neutral is net benefit, for sure.
Mike P. 1:07PM (2/09/2009)
...I agree with that, say, if you're on the highway (not coming to a stop) on a grade that's gentle enough that you don't have to use the brakes.
If you're coming to a stop anyways, you might as well stay in gear. If the grade is steep enough such that the acceleration due to gravity puts you over the speed limit and you have to brake anyways to stay under it, you might as well stay in gear (save gas and brakes, as long as the RPMs aren't too high). You can control the amount of engine braking by changing the gear--in 5th or 6th gear, there isn't much engine braking at all.
Then there's the varying legality of coasting in neutral.
I suppose it depends on the situation, but in general I think it's better to stay in gear.
220v 1:33PM (2/09/2009)
What's with the interest in the legality? Have you ever been pulled over for coasting? Coasting in neutral for that matter? I haven't, and I do it all of the time.