I was reading a news article about the first people in West Michigan to get a Chevy Volt. So I decided to do some number crunching.
The Chevy Volt price is around $41,000, you will get 35 miles on a charge just running off of the electric motor (4hour charge @240volts), an extra 344 if you use the gas engine (80hp requiring premium fuel) after the electrical charge is used up. With a top speed of 100 mph.
The VW Golf TDI is about $23,000 with 30city/41highway, that is with a 2.0 140hp TDI that will do 16.4 @83mph on the 1/4 mile 0-60 in 8.7.
So adding some numbers up 30mpg with a 14.5 gal tank that's going to get you 435 miles on a tank.
so with that said the TDI will give twice the power, half the cost, and more mpg


http://blogs.insideline.com/straightline/2010/05/il-track-tested-2010-volkswagen-golf-tdi-vs-2010-volkswagen-gti.html
http://gm-volt.com/2010/11/24/official-2011-chevrolet-volt-epa-fuel-economy-released/
http://www.chevrolet.com/volt/#technology
http://www.vw.com/en/models/golf/features_and_specs.html

so with that said the TDI will give twice the power, half the cost, and more mpg

The price part is true(even with federal tax grant of $7500 bringing it to $33,500), but it has less power actually and gets less MPG unless you're usually on long highway trips. It's also close in acceleration.


http://www.motortrend.com/oftheyear/car/1101_2011_motor_trend_car_of_the_year_chevrolet_vo lt/specs.html

I'm not in the market for either but one thing I'd consider is that when fuel prices go up diesel is usually impacted more, at least where I live. When gas hit $4.50/gal a few years ago diesel was about $5.35/gal.

If you are actually considering one of these vehicles I suggest you do a lot more research before making a decision and do better number crunching.