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Discussion Starter · #1 ·
Hi folks! I'm new to Audi/VW and I have a few questions...

1) May I know why ppl want 'TDI'? Isn't Diesel gas hard to find among gas stations in US (in Seattle where I'm at) and therefore very inconvenient? I was under impression that diesel cars cause pollutions (at least when I was a little..all these diesel trucks!)... apparently that's not the case nowadays...

2) What do people pay for their A5's nowadays? MSRP or what's the % of discount?

Thank you in advance for your input...
 

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Hey cellg8, welcome to the forum. First, update your profile with your location please.

I don't know if the A5 TDI will come to the US, apparently the new A4 will have TDI engine available.

Diesel are clean nowadays, many car brands are changing to diesel. Ferrari had a bio-diesel F430 at the Detriot autoshow, the R8 lemans concept is also diesel. I believe that because its clean the US will have more diesel cars available soon, and gas stations have to go along with it. Oh, and the new diesels are fast too, so its all good :)
 

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Modern turbo-diesels do have lower CO2 emissions than equivalent sized gasoline engines, but on the other hand they do produce more other pollutants/harmful particles. DPF and AdBlue and things like that go towards solving those issues, but they are not always standard - nor do they fully solve all issues of course so the debate (and development) continues which engine type is cleaner...

Of course diesels also have better miles per gallon than gasoline engines usually have, which does have additional environmental (and financial...) impact.

It is not a black and white issue, diesels are quite trendy in Europe at the moment though, but I think developmens in gasoline engines like FSI and of course turbo charging will keep both juices running in our engines for a while...
 

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Discussion Starter · #4 ·
Thank you both for your helpful info. I really appreciate it.
 

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The diesels by nature produce more particles (soot/smoke) and NOx (nitrogeous oxides) which are harmful to the environment and can also cause cancer (soot).

This has to do with the fact that the diesel engine operates with diffusion (slow) burning. However, modern diesels operate with very high injection pressures, sometimes up to 2000 bars, which effectively reduces the amount of harmful soot. Also, all diesels nowadays use EGR (exhaust gas recycling) which lowers the combustion temperature to reduce the amount of NOx.

Further, the TDI has a DPF (particle filter) which reduces the soot levels even more!

The same emissions requirements apply to diesels as gasoline engines.

In terms of fuel consumption and CO2-emissions, well, they are linearly related. So if you consume less fuel you produce the same amount of less CO2. Easypeasy!

And since a diesel consume about 20% less fuel than a gasoline engine, they also emit about 20% less CO2 (not fully true though since the fuel quality (H / C balance) of the fuel also influences).

Hope this sorts it out :)

I went for a Diesel :D Just love the extra power at low revs!
 
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