VW delays Jetta TDI diesel in U.S.

The comment posted by one reader in response to the atricle was par for the course...

too bad By 2ms from USA on 11/9/2007 "Diesels are more appealing to people than ever right now with all the current focus on global warming -- their CO2 emissions are untouchable by both gasoline and gasoline hybrids cars. And, of course, their out-of-city mileage is untouchable too."

 

Just in case anyone's interested:
Prius emits 110 g/Km CO2
Jetta Diesel: 140 g/Km minimum.
Regardless of your favorite unit of measure, the ratio between these numbers says it all.

 

<div class='quotetop'>QUOTE(Tideland Prius @ Nov 14 2007, 04:33 PM) [snapback]539659[/snapback]</div>

Not at all.

Diesels make most of their power in the lower RPM ranges, both HP and Torque... that's why they 'pull' so well. Most transmissions on a diesel like car have to shift at a very Prius-like 4 or 5K RPMS.

The advantage of the diesel is the highway mileage, no doubt. When you consider the Jetta TDI and the Prius get the same mileage, and the TDI does it without any HSD benefits, you have to be impressed. When you realize the Jetta is quite a bit heavier (and safer) than the Prius, you kinda wonder if HSD is dead weight on the highway.

 

<div class='quotetop'>QUOTE(Jonnycat26 @ Nov 14 2007, 01:39 PM) [snapback]539662[/snapback]</div>

Heavier is not necessarily safer. The Prius received the highest safety rating from the EU - 5 stars. It was one of only eight cars to receive such a rating for occupant protection. I have no idea what the Jetta's is.

 

<div class='quotetop'>QUOTE(Tideland Prius @ Nov 14 2007, 04:47 PM) [snapback]539669[/snapback]</div>

Not at all... diesels have a much flatter power curve that does taper off dramatically at higher RPMs. And even with a Turbo, you're just not going to get the kind of torque a diesel produces. Not to mention that the diesel needs less fuel to make the power that a gasser produces, which is kinda of the point of going diesel anyway.

 

<div class='quotetop'>QUOTE(Tideland Prius @ Nov 14 2007, 08:28 PM) [snapback]539737[/snapback]</div>

I mean a flatter curve... And I used to own the old 1.8T, and it was a thing of beauty to drive. But the TDI had more umph off the line (altho it wasn't as fast once you got moving as the 1.8T) and it clearly used more gas than the TDI.

 

<div class='quotetop'>QUOTE(Jonnycat26 @ Nov 14 2007, 11:39 PM) [snapback]539662[/snapback]</div>

The reality of the 'highway' over here is lots of stop and go traffic. And that's where the HSD shines.

 

<div class='quotetop'>QUOTE(Jonnycat26 @ Nov 14 2007, 03:39 PM) [snapback]539662[/snapback]</div>

Casting doubt on a misconception squashed a long time ago. Smoking isn't harmful, eh?

 

<div class='quotetop'>QUOTE(Jonnycat26 @ Nov 14 2007, 04:39 PM) [snapback]539662[/snapback]</div>

You mean the 2-Mode? HSD still use the electric path even on the highway.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Nov 15 2007, 11:23 AM) [snapback]539992[/snapback]</div>

No, I did mean HSD... I just wonder why there's no more benefit, or why it's not more competitive with the TDIs given the weight differences.

 

<div class='quotetop'>QUOTE(Jonnycat26 @ Nov 15 2007, 11:42 AM) [snapback]540011[/snapback]</div>

HSD's advantage is clear. Despite 15% less energy in the gasoline, it can get as good or better than TDI on the highway.

The real question should be toward TDI.... despite 15% more energy in diesel fuel, why is it's MPG not as good as Prius HSD?

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Nov 15 2007, 03:00 PM) [snapback]540139[/snapback]</div>

As mentioned above, it's significantly heavier, uses wider tires (not LRR either), and isn't as aerodynamic. So why is the HSD not better than the TDI?

 

<div class='quotetop'>QUOTE(Jonnycat26 @ Nov 15 2007, 03:24 PM) [snapback]540156[/snapback]</div>

Come on! The HSD benefit is clear. Yaris Sedan with 1.5L / P185/60R15 tires get 35 MPG where Prius gets 45 MPG (2008 EPA) on the highway. Prius is a lot heavier than Yaris and yet gets 29% better highway MPG.

If Prius runs on diesel, HSD can boost another 29% to the VW TDI's MPG on the highway.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Nov 15 2007, 04:08 PM) [snapback]540184[/snapback]</div>

The Yaris is about ~2300 lbs, the Prius is about ~2700 lbs, and the Jetta is ~3200 lbs... so the Jetta is packing more weight than the Prius and Yaris, and handily beats the Yaris and holds it's own with the Prius.

My point stands.

 

<div class='quotetop'>QUOTE(Jonnycat26 @ Nov 15 2007, 04:33 PM) [snapback]540195[/snapback]</div>

Yaris is ~2300 lbs runs on gas. Prius is ~2900 lbs runs on gas. The difference is 600 lbs heavier (sub compact vs. mid-size) and 29% better highway MPG.

TDI ~3200 lbs runs on diesel. If a HSD Diesel is two classes bigger than VW TDI AND 600 lbs heavier, this HSD Diesel can get 29% higher highway MPG.

There is no way to spin around it dude!