Jetta Diesel Tops Prius in Fuel-Economy Marathon... NOT!

Terrain makes a huge difference in fuel economy. I would get 52 - 54 mpg in my Jetta on trips from Tennessee to Michigan. That was @ 65mph in TN, 75 mph in KY, 70 mph in OH, and 80 mph in MI. 90% of that traveled on I-75

What do you consider to be normal noise and smell for diesels? Are you comparing them to Ford F350's and tractors or to say a 1998 - 2005 VW or Mercedes?

My 2003 TDI is louder than a gasoline vehicle outside of the vehicle but quieter than the gasoline model at speed inside the vehicle. This is due to only needing to run at 2400 RPM to go 70 mph. My TDI is also quieter inside than my Prius.

The new 2009 common rail TDI is as quiet as the gasoline model standing next to the car with the hood open and even quieter inside the vehicle.

I can smell diesel exhaust in my TDI if I back up with the windows down. There is not smell with the windows up. I didn't notice any diesel smell while standing next to the new 2009 TDI with it running.

 

That's funny since the wagon wasn't the topic we were discussing. BTW, your cargo and passenger volumes are reversed.

I'm actually in favor of wagons though, beats the tar out of SUV's/vans/light trucks.

Fuel economy for the 2009 TDI Jetta Sportwagen per the EPA is 29 city, 40 highway, 33 combined. (Add 1 mpg for manual transmission.) Annual greenhouse gas emissions are estimated at 4 tons for the Prius and 6.4 for the Jetta TDI Sportswagen.

Which is misleading since from your own description the Prius is getting the difficult route and the Jetta the easy one. Reverse the services and the Jetta will look bad.

So for the same service the wagon as expected has more capacity, but is a diesel (negative in several regards) and costs more for initial purchase, has much lower fuel economy, and the fuel is more expensive.

 

They aren't so noisy and smelly like they were, and VW has a lot of experience with the TDI engine. As a plus, if you use biodiesel, the exhaust smells like french fries as you drive along.

We need all high-efficiency options that we can get. There will be people who won't buy a Prius for one reason or another, so if we can get them in a car that gets 40 mpg (at least on the highway), it's still not a total loss.

I know people rail on diesels because of a gallon of diesel contains more hydrocarbons (thus fuel and pollution) than a gallon of gasoline, so some (or all) of their more noticeable advantage is taken away when you do the math. But the fact is, when you refine petroleum, you end up with both gasoline and diesel, so it only makes sense to have efficient vehicles available for each type. Until we get the natural gas and electric cars out in mass, anyway.

 

What year Prius? There was a change to the back seat in '06 to give it 1" more headroom.

 

Good point. My experience is all about what I have to listen to as the non-diesel driver behind or beside them at stoplights. I have to hear them in my car. I've certainly noticed that they are quiet inside, but I'm not inside. I love how quiet the world is at a stoplight in my car with the engine off. Now if other drivers boomboxes also shut off at stoplights...

Same point here -- its all about me as the driver of the other car. I have to smell every diesel I'm behind. If diesels made up the bulk of cars on the road, it would be a far less pleasant driving experience. I certainly would prefer more electric vehicles.

 

Its not a loss at all. I agree completely. If diesels get us more fuel efficient faster, I'll learn to like the noise and smell..

 

Again, are these relatively new diesel CARS or medium duty trucks like a Ford F350 or Dodge Ram 3500? I really doubt that most people would notice that my Jetta is diesel but the trucks are incredibly loud to sit beside or behind. Don't even get me started on the idiots that chip their trucks so that they create huge clouds of smoke when accelerating.

My Jetta is a 2003 and uses an engine that was first produced in 1993. It doesn't have catalytic converter, particulate filter, or advanced common rail injection system of the new TDI. However, it was the most fuel efficient wagon with the cleanest emissions that I could buy at the time.

Since I've had my Prius is does seem odd when the Jetta doesn't turn off when stopped at a light. However, BMW has incorporated auto stop start into their diesel 1 and 5 series cars and is in the process of expanding this to cover the entire range. Personally I think that all vehicles should have stop/start as standard.

I don't know about that. I've spent months traveling through Europe with my last job and didn't notice the air quality to be any worse than US cities.

I would also like to see electric vehicles. We really don't need the Prius as we don't use it to travel long distances. It could easily be replace by a electric vehicle that goes 50 to 75 miles on a charge.

 

I have a 2005 so that would explain it. My Prius would have 1.1" less rear headroom than my friend's 2006 Jetta sedan.


Shawn_Clark:
The sedan may have been the subject of this test, but it doesn't change the fact that you can get a significantly larger version of the Jetta that gets the same fuel economy.

Yes, the EPA rates the Jetta at 29/33/40 but even they admit that the new standard rates diesels up to 18% lower than reality. This is backed up my personal experience and every test I've read that have consistently beat the official EPA numbers. Notice that Popular Mechanics beat the EPA by 12%.

Even if I only got PM's numbers and drove 100% city.

10,000 miles / 44.7 * $3.343 = $747.87 or $0.075 per mile for the Prius
10,000 miles / 32 * $3.796 = $1186.25 or $0.119 per mile for the TDI

So even in the worst case it is only $0.044 per mile difference. Again, I'd drive the TDI; the interior and handling of the Prius is that bad. I hope that these issues are addressed is future hybrids. I doubt Toyota will do it but maybe Honda has with the new Insight.

($3.343 is the national average for 87 octane gasoline for the past 52 weeks)
($3.796 is the national average for #2 on-road diesel for the past 52 weeks)

 

J: In my friend's Prius, if I sit up straight in the back seat, my hair will hit the liner too...but just barely (I'm 5'9" with a 32" inseam). As far as legroom goes, with the seat all the way back, I still have a good 2" from my knees to the back of the seat. When you've sat in the back of the Jetta, was the driver's seat all the way back? There might be a slight apples/oranges arguement here if the seat wasn't fully back.

Otherwise, though, thanks for the reply/input. :rockon:

 

The seat was not all the way back, though my friend that owns the car is 6'3" so it was quite a ways back. My knees did not touch the seat and I was comfortable for 2 hours.

 

Just keep in mind that running biodiesel is strictly verboten by VW, and will affect warranty status. They don't recommend anything above 5% BD in a mix. Eventually that will change, but in the mean time does not make BD an option for most folks.

As to the hydro carbon content / have to use both argument I disagree. The carbon content is important as CO2 output is proportional to carbon content of the fuel. For the same MPG, a diesel will put out 15% more CO2. Petroleum does naturally contain both light components to make things like gasoline, and heavy components to make diesel and kerosene. The problem with your statement is that the longer hydrocarbons in the heavy components can be broken down to make lighter ones. In fact we already convert (crack) part of our diesel production into gasoline in the US. The reverse process is not possible. You are stuck with the gasoline, but the diesel part is negotiable.

I agree 40mpg is good, but only with all things being equal. From a CO2 perspective, it is equivalent to a 34.8mpg gas car. From a current fuel cost perspective, it equivalent to 37.5mpg. From a crude petroleum consumption standpoint its equivalent to 35mpg. From a NOx perspective, its like a 9.6mpg Prius. For CO its like a 12mpg Prius. For NMOGs its like a 36mpg Prius. For the earlier TDI, the CO2, cost and oil consumption numbers stay about the same, but the emissions numbers generally get much worse. You can see a pretty detailed comparison I did on the emissions here:
http://priuschat.com/forums/prius-hybrid-news/49909-2009-vw-jetta-tdi-emissions-results-in.html

For jhinton's situation, I can see how one of each works pretty well. Personally I would not choose to trade the comfort and driving experience difference for the greatly higher emissions in the earlier TDI given the performance of today's Prius. I understand though that at the time he purchased his TDI things were different. For the average person who needs a car that will perform well under both highway and city conditions, and assuming fuel economy and/or emissions are a major consideration I still the the Prius is far and away the better choice.

Rob

 

There, fixed that for ya. Your Jetta was far from the cleanest vehicle on the road when you bought it.

Gee, that's only 60% more in fuel costs than the Prius, what a bargain!

Just giving you a hard time, but 60% sure sounds a lot different than 4.4c/mi.

I doubt the interior will be much different, but I'm positive that the Honda will handle better than the Toyota.

Toyota is well known for creating vehicles which are boring to drive, Honda is well known for creating vehicles which are fun to drive.

But the interiors have always seemed pretty similar in feel/comfort to me.

 

I never said it was the cleanest car at the time. I was looking for the most fuel efficient WAGON and the Jetta TDI is by far the most fuel efficient. The TDI is the lowest emission engine available from VW but, upon further investigation, it was not the cleanest wagon available in 2003.

Here are the cars I seriously considered back in 2003:

Vehicle ---------------------- CO ----- NMOG ----- NOx ----- PM ---- Total (g/m)-- EPA Mileage (08-STD)
VW Jetta TDI Wagon ------ 0.40 ---- 0.0500 ---- 0.54 ---- 0.05 ---- 1.0400 -------- 35 / 39 / 45
Pontiac Vibe ------------- 0.33 ---- 0.0314 ---- 0.06 ----- N/A ---- 0.4214 -------- 25 / 28 / 33
Ford Focus Wagon -------- 0.50 ---- 0.0390 ---- 0.11 ---- N/A ---- 0.6490 -------- 24 / 27 / 30
Mazda Protégé 5 --------- 0.64 ---- 0.0296 ---- 0.07 ---- N/A ---- 0.7196 -------- 22 / 24 / 28
Volvo V-70 -------------- 0.27 ---- 0.0227 ---- 0.01 ---- N/A ---- 0.4027 -------- 19 / 22 / 28
Volvo V-40 -------------- 1.94 ---- 0.0710 ---- 0.06 ---- N/A ---- 2.0710 -------- 19 / 22 / 27
Data from: (Annual Certification Test Results & Data | Cars and Light Trucks | US EPA)



In case you’re curious, here are the emission for the hybrids available in 2003:

Vehicle ------------------------- CO ----- NMOG ----- NOx ---- Total (g/m)
Honda Insight (CVT) --------- 0.01 ---- 0.0037 ---- 0.01 ----- 0.0237
Toyota Prius (CVT) ----------- 0.18 ---- 0.0024 ---- 0.01 ----- 0.1924
Honda Insight (Manual) ------ 0.60 ---- 0.0290 ---- 0.00 ----- 0.6290
Honda Civic Hybrid (CVT) ---- 0.78 ---- 0.0158 ---- 0.14 ----- 0.9358
Data from: (Annual Certification Test Results & Data | Cars and Light Trucks | US EPA)


The TDI was also the cleanest engine available from VW in 2006. Here are the numbers:

Engine -----------------------CO---NMOG-----NOx----PM----Total (g/m)-----Standard----2008 EPA Mileage
2.5L Gas (GVWXV02.5257)-----0.41--0.0033----0.000----N/A------0.4133--------T2 B2---------19/22/28
2.5L Gas (GVWXV02.5253)-----1.26--0.0290----0.029----N/A------1.3034--------T2 B5---------19/22/28
2.0L Gas (5VWXV02.0224)-----0.77--0.0205----0.012----N/A------0.8025-------- T2 B5-------- 21/24/29
1.9L TDI (6VWXV01.9238)-----0.04--0.0194----0.310---0.046-----0.4154--------T2 B10--------30/33/37
Data from: (Annual Certification Test Results & Data | Cars and Light Trucks | US EPA)
Note: 2006 is the last year that EPA data is available for diesel engines.

The first 2.5L gasoline engine is the CARB engine sold only in the 5 states with CARB emission regulations. The second 2.5L gasoline engine is the Non-CARB sold in the remaining 45 states. The 2.0L is the gasoline turbocharged engine sold in CARB states. The 1.9L is the turbocharged diesel sold in Non-CARB states. As you can see, not only is the diesel cleaner than the CARB-only 2.5L, it is 2 or 3X cleaner than the other non-CARB engines. In a note for used car shoppers, the 2006 TDI is also cleaner than the 2003 5 speed Insight and Civic Hybrid.



MISCRMS has pointed out that for 2009 the 2.5L is the cleanest engine available from VW in CARB states. His excellent comparison is available here:

http://priuschat.com/forums/prius-hybrid-news/49909-2009-vw-jetta-tdi-emissions-results-in.html

However, I will reserve judgement until EPA data becomes available since I, like most Americans, don’t live in a CARB state.




The TDI’s are also by far the cleanest and most fuel efficient engines offered by VW for sale in the United Kingdom. That data can be found here:

http://priuschat.com/forums/2010-toyota-prius/49534-why-no-prius-diesel-hybrid-4.html#post704560

It is a bargain for a vehicle that is not only more comfortable but also much more fun to drive. (That is more fun to drive in the traditional sense, not the tech / geeky sense of those here on Prius chat. )
Really $400 a year is quite small when compared to the total cost of operating a vehicle for a year especially, with fuel efficient vehicles.

 

Sorry, I misread - you said you were looking for the "most fuel efficient wagon with the cleanest emissions that I could buy at the time.". While you bought the most fuel efficient wagon, you also bought just about the dirtiest.

No, it's not. You're reading the data wrong, or selectively.

The only car that is dirtier is the Volvo V-40, which I assume is also a diesel.

All much, much cleaner than your TDI, except for the CO levels from the Insight manual and HCH which are 50-100% higher.

No, the TDI is dirtier. It falls into the T2 B10 category which is much less stringent than T2 B5 or even the T2 B2 of the CA emissions model (which is very squeaky clean).

The 2003 TDI is far, far dirtier on the important pollutants such as particulate matter an NOx. With the other pollutants, it's not that much different. Which is why the TDI falls into a much lower emissions class than the gas cars.

Hmm, that directly contradicts what he says later in the thread.

Which sums up my thoughts, very neatly. I may change my mind once I see the latest emissions data for the '09 TDIs selling here in the states, but until then...

 

Just because the vehicle is allowed to emit a certain amount of pollution doesn't mean that is does. The Bin system doesn't take into account total emissions but instead breaks the emissions up into 5 components with a 5 point scale for each. A vehicle that ranked 0-0-0-0-5 would be rated a 5 while while a vehicle ranked 4-4-4-4-4 would be ranked a 4. Which is better the one that puts out 5 units of pollution or the one that puts out 20?

I rank vehicles by total emission based on EPA data. In 2006 the TDI had 1/2 the total emissions of the 2.0T and 1/3 the total emissions of the 2.5.

CO (Carbon Monoxide) is an important emission to me considering that is a poisonous gas that can kill you within a hours.

 

Yep, I noticed that originally as well, but let it pass. He's not really trying to make reasonable comparisons but instead justify the Jetta over the Prius because he prefers driving the Jetta. :cheer2: It is irritating how frequently the Jetta fanatics try to misrepresent the Jetta here, but pretty much business as usual.

 

CO emissions from all modern cars are so low now, that CO poisoning is very low.

You'd literally have to be sucking on the tailpipe of a modern car to die from CO poisoning these days.

That said, weighing all pollutants equally is obviously not the best way to weigh pollutants since their effect on the environment is very different. If you wish to go down this route, why don't you also add in CO2 emissions?

We're beating a dead-horse here, though. All these arguments were already made in that thread you linked to earlier, and it's obvious that you would rather weigh the facts in such a manner that tilt the scales in the behaviour of the outcome you desire.

 

Hi Guys
First post from a new member here in the UK - interesting to read the TDi stuff, over here in the UK everyone is buying diesels, almost all new company cars are diesel - even though diesel fuel fuel here is about £5.35 per gallon (remember our gallon is a little bigger than yours, its about all we have bigger thanyou! And petrol is around £4.85 per gallon!

My company car is a Prius T-Spirit, and we get just the same discussions with the unitiated (do you plug it in, does the battery go flat, etc) but when we talk about mpg, Road Tax £15 per year compared with normal up to £170 per year etc, people start to see a different side to it.

Looking forward to some interesting chats - as for the TDi, to get such awful figures from a TDi how are they driving it? Over here 45-60mpg is normal for VW TDi's!

John

 

you guys have different mpg standards (imperial vs US) and strong cats have increased consumption and reduced speed of US Jetta...