Prius VS. TDI (which to buy)

[Unforgiven]

Hmm, still I would take a Prius and the hybrid batteries over the explosive potential and EXTREME cost increases of hydrogen fuel cell or ethanol driven vehicles. Having said that, I would think Prius for city work with occasional highway, while TDI for mostly highway use. One big factor that many here but not many outside understand is that turbo's operate best under certain higher heat conditions and loads than a non turbo, and that "blowing the carbon" (archaic term) is what helps keep them spinning properly. Take note about the use of ultra low sulfer diesel fuel and the requirements of keeping your idle time low to prevent soot build up and the associated troubles with it. (Semi drivers learn this quick as a failure for us can mean a 17,000 repair bill)

[MetroMPG]

Originally Posted by Deezler

The energy impact of a vehicle must always be considered over its entire lifetime

I'm glad you said "energy" impact. Do we also compare the energy content of diesel fuel vs. gasoline in evaluating their merits? A gasoline powered vehicle getting the same MPG as a diesel is significantly more energy efficient.

I find these discussions often tend to end up in the realm of "how many angels can dance on the head of a pin?"

[Deezler]

Originally Posted by MetroMPG

I'm glad you said "energy" impact. Do we also compare the energy content of diesel fuel vs. gasoline in evaluating their merits? A gasoline powered vehicle getting the same MPG as a diesel is significantly more energy efficient.

I find these discussions often tend to end up in the realm of "how many angels can dance on the head of a pin?"

Yes, I think that would certainly be fair game for consideration. And also how diesel requires far less energy to refine, including the nasty chemical manipulation and alteration necessary for gasoline. Or, using my car as an example, how the diesel engine is epa rated at 44 mpg while the 2.0L gas is rated at 29 mpg. (52% better mileage with 12% more btu's per gal. Before the EPA decided to lie about average diesel fuel economy, the stickers showed a 58% advantage for the diesel engine.) You simply cannot argue the logic of diesel engine efficiency superiority. Direct Injected gasoline engines may start to blur the lines a little bit.... which is awesome.

Of course, ymmv. Certainly kudos are due to those of you pulling down stellar mileage figures with gasoline. And I don't disagree that a hybrid is still a better choice for all city driving. But when I see a prius rocket along at 80+mph on the highway I cringe a little bit. Happens a lot in southeast MI.

Not really feeling you on the angel pin thought...?

edit; just found a different source citing more like an 18% btu advantage for diesel... numbers seem to be all over the place. Also interesting to note might be that those running pure biodiesel are actually at a lower btu level / gal than regular unleaded gasoline.

[dcb]

I don't know why there isn't a diesel hybrid. Just a big enough diesel to keep you moving on the hiway and recharge a bit (and give you some decent biofuel options), and an electric motor to help with the acceleration up to speed and around town.

[Deezler]

Originally Posted by dcb

I don't know why there isn't a diesel hybrid. Just a big enough diesel to keep you moving on the hiway and recharge a bit (and give you some decent biofuel options), and an electric motor to help with the acceleration up to speed and around town.

For real DCB. I can only speculate that
A) the combined price of both technologies is just way too high and
B) the start/stop function of the hybrid powertrain using a diesel is simply very hard to make transparent. Who the heck cares if the thing shudders once in a while when you are getting 70 mpg...

plus add emissions reqs... and it gets very complicated.

[BrianAbington]

I would think that a diesel system similar to what the volt uses would be pretty sweet...probably would be over a 1,000 miles pergallon compared to the gas system the volt uses.

Interesting thing though...this discussion was to help my wife and I narrow our choices as we save up to buy a new car next year. Well the transmission went out in the mirage last night. I only have first gear and it vibrates like crazy when stopped, and acclerating, and when slowing down...so its pretty much shot.

So now were looking for an imediate replacement...think TDIs out for a couple years still.

but lets keep this discussion going. this is a good thread. Never seen a TDI vs. Prius thread before.

[G60ING]

100k miles in a year? It sounds like you will be doing a lot of highway driving, if thats the case then I highly recomend a TDI. If you plan to drive mainly off the highway then I'd recomend a hybrid.

I do NOT recomend converting to WVO as it will tear up a TDI very quickly if you are not ULTRA carefull and 100% knowledgeable.

[G60ING]

Originally Posted by Binger

Never seen a TDI vs. Prius thread before.

Go search TDIClub.com and you will find dozens like this. I am fortunate in the diesel vs hybrid discussion because my dad has owned an Insight and currently owns a Civic Hybrid so get to compare them against my TDIs. For my type of driving I can say that a hybrid is not the best choice.

[BrianAbington]

Originally Posted by G60ING

100k miles in a year? It sounds like you will be doing a lot of highway driving, if thats the case then I highly recomend a TDI. If you plan to drive mainly off the highway then I'd recomend a hybrid.

I do NOT recomend converting to WVO as it will tear up a TDI very quickly if you are not ULTRA carefull and 100% knowledgeable.

no...I'm sorry if I wasn't clear...the car has just shy of 75,000 miles on it and I calculated that with my commute to work it would be just past the 100,000 point by this time next year.

But as I said in the last post...the transmission just went out so...the search for a cheap immediate replacement is on.

[COcyclist]

If "cheap, immediate" replacement is truly the issue, a small used Corolla (gas/manual tranny) may be what you need. You pay a premium for the extra technology in either the Prius or TDi that could take years to recoup through fuel savings alone. Used Toyota gassers should be plentiful and reliable even if they give up a little in ultimate fuel economy.

If you want fuel economy and performance too, get the TDi.