I am just wondering i know that factory turbos add power but i hve heard that they are mainly for fuel economy i was wondering if anyone knew the real reason for this thanks for all your help

 

you should go to http://www.howstuffworks.com and read up on turbos

 

>>i know that factory turbos add power but i hve heard that they are (substitute "also" for "mainly") for fuel economy<<

Yes.

 

I like to refer to a lot of factory turbocharged cars as having "afterthought" turbos.
A lot of the chrysler turbos for example. It seems like they got done designing the minivan, and said "hey, this thing has nowheres near enough torque. Lets throw on a turbo

Then of course you have the DSMs, Supras, etc. where the point of having a turbo is obviously to add power.

In some instances, turbocharging a car will slightly increase your MPG, but its very dependant of your driving habbits. You definatly need to read up more on turbos and turbo theory.

 

the 91 isuzu impulse RS AWD turbocharged car made 160 HP 150 ft/lb torque, and got 36 MPG on the freeway.

that's pretty good economy if you ask me, for a turbocharged car,

or how about the volkswagen TDI, Fuel mileage in the high 40's low 50's..

 

Thats the reason why most semi's are Turbo Diesel - fuel economy... however on most non diesel cars, they are there for power. Speaking of turbo minivans. I saw some guy at the track about 2 years back pull up to the line in a turbo plymouth. he was wearing a helmet and was up against a Z28 camaro or something. We were all kinda snickering under our breaths until the guy took off - 13.4 sec 1/4 pass.. our jaws dropped.