In the 2 categories where Jetta TDI won (highway & backroads), the margin was narrow.

In 2 that Prius won (city & fuel cost), the margin was extreme. The other (greenhouse) was narrow.

Too bad there wasn't a SMOG emission category. That's another extreme advantage for Prius.

Of course, what's the point of comparing a MANUAL transmission to Prius anyway? It would be far more appropriate using an automatic... but then, Prius would sweep every category.

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The Prius won the OVERALL over the TDI. Take notice.

In Round 1, Driving up hills for prolonged time (see the photos) requires a lot of torque and power. (for those that think it takes power but not torque, shift your bicycle into a high gear and try riding uphill) The battery on the Prius would be exhausted, and the gasoline engine would be struggling. The diesel would be at home driving up hills.

For Round 2, it's no surprise the Prius won. It's hybrid system is optimized for stop-and-go traffic. The engine even shuts off at stop lights.

Round 3. For highway driving, I would think the engine with the lowest displacement (liters) would be the most efficient, since all it has to do is simply maintain speed. Any displacement beyond the minimum required to do that is wasted. That is a comparison when all cars are using the same fuel. The diesel won because diesel is more efficient.

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In an earlier thread, many people (including myself) assumed that because diesels have more carbons per molecule and black soot on their rear bumpers, they "must" also emit more CO2, but this article clearly stated "Greenhouse gases are not the visible pollution (called particulate matter) that can be seen chugging out of the Jetta's tailpipe."

I guess that is one way of looking at it. What I noticed was the HUGE difference between EPA mileage and actual mileage for the TDI. The EPA rates the '05 5 speed TDI @ 30/39. Edmund's got 47 mpg on backroads and 48.9 mpg on the highway @ 75 mph. That is 20.5% and 25.4% better than EPA respectively. It even beat the EPA in the city by 5.2%.

Why use a manual? Because the object was to get the best fuel economy and that is what they had. VW also sold a lot of 5 speeds mated to TDI's. The auto is only rated 1 mph worse than the manual. (30/38 vs 31/39)

I thought being objective was to make comparisons as similar as possible.

Also, keep in mind how much more efficiency can vary when manual shifting is involved.

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How do you suppose they measured mileage given the uncertainty of the Prius gas tank?

Tom

If the object was to be as similar as possible why include the Smart fortwo at all?
Why compare a 5-person coupe, 5-person hatch, 2-person hatch, and a 5-person sedan?
Why use a CVT, Auto, Manual, and clutchless manual?
Why compare a hybrid, turbo gas, turbo diesel, NA gas?

Why ask Why?

I prefer a manual so I don't see a CVT or automatic as being a positive feature. I bought my Prius in spite of it having a CVT and because I couldn't find a Civic Hybrid within 500 miles.

it was not to compare similar cars... it was looking at the cheapest way to get around. storage, passenger comfort, legroom, etc...not part of the equation.

i like the line "The Prius... if you have the money.

price a TDI jetta lately??? how much money do you save by buying one of them??... not much

Regular Unleaded-$4.15
Diesel-$5.00

which is cheaper now.....? hmmmmmm

Actually, as John knows (but will never point out) the DSG Auto TDI cars get better mileage than the manuals. SO using a manual TDI was putting the TDI at a bit of a disadvantage.

Wasn't the reason for this to provide data just like that?

All transmissions have peaks & lows. With it, I could have pointed them out. But they didn't use it. Why?

Do you have data to support your claim?

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Just those pesky EPA ratings, which I've sent you before.

Well, then there's no contest. A minor bump is still not enough.

Of course, we all know estimates are never as good as real-world.

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i bet prius could have won out on top in all categories had they chosen to use a non-touring model

Dude... I mean, come on.

I was just pointing out that the manual is not as efficient as the manual, which is what people were saying.

I'd be more concerned with the driving styles of the different drivers. We picked up our 08 Touring on Valentines Day and we are currently averaging a bit over 58 MPG. I expect this to climb to around 60 once the weather here in NE Ohio decides to get with it and stay warm for more than a couple hours.

The differences between Touring and non-Touring just don't effect mileage all that much.

David

The "soot" is generally considered particulates (PMs) and aerosols (PMs and gas together) correct? Quite different than greenhouse gasses in their effects on our health and local environments. Diesels definately put out more of those than does a gasoline vehicle although one should not discount the fact that particulate size has decreased overall with catalytic converters. This could be deemed even worse than the large particles since they remain airborn longer and are more easily driven through the respitory system (similar to the problems with nanotechnology). Any better info on this? I'm not well served in anatomy.

Wow... my touring never broke 45mpg/tank until I hit 20k miles on the odometer.