Why does the Volkswagen Jetta TDI get so much more miles per gallon than a regular Jetta?

[GearHead318]

What does the TDI mean? Is this some kind of hybrid? A TDI is listed at 36 mpg city, but a regular Jetta gets only 22. What gives?

[just522]

I can't remember what TDI stands for, even though I've read it in my owner's manual. People "interpret" it to mean Turbo-diesel, which it is, and the fact that it's a VW diesel is the reason it gets so much better gas mileage than any gas car. I own a 2002 model, automatic transmission, and I get 47 highway. I bought my son a 2004 model, 5 speed, and he gets 53mpg highway. A co-worker of mine in the railroad business bought a 2000 model, 5 speed, and he gets 53mpg. VW is well known for very good diesels. I had a 1981 VW Rabbit diesel, 5 speed transmission, and I got 57 mpg before I finally had to give it up with 326,600 miles, all original equipment except a new set of rings my mechanic put in at 250,000 miles since I broke a head gasket and he felt it would just be wise to replace the rings since he had the engine taken down so far already. If you can get a TDI, which cost a bit more than a gas model, get it!! It's well worth the investment. I got my son his 2004 model since he came home from his first tour of duty in Iraq very close to his 21st birthday. He's now finishing his second tour in Iraq, but he'll be driving his 2004 model for quite a few more miles. The EPA has put more restrictions on VW's diesels, so they can't import any more till the 2008 model year which is just one year away. I hope you can get one. You'll be glad you did. God Bless you.

[Weatherman]

Turbo Direct Injection.These engines run on diesel fuel which is very highly combustible compared to normal gasoline. They are turbocharged which increases effeciency, and the fuel is injected directly into the combustion chamber which also increases effeciency. When you combine these attributes, you end up with amazing fuel economy.Every big 18 wheeler truck you see on the road is also turbocharged and runs on diesel fuel. Those big trucks need all the fuel economy the can get because they run all day long.If you ever get one of those Jettas, remember they only run on diesel. They sound different, too...kind of noisy.By the way, I work at a dealership and I have seen TDI's with over 250,000 miles that run just fine...they seem to last forever.

[wolf]

Turbo Direct Injection.That is a TDI.It gets more mileage because it is diesel.It is a turbo charged diesel engine,that uses direct injection technology to deliver the fuel.It is not any form of a hybrid.