Try this web site - http://www.maintainyourcar.com
it has quite a bit of info about getting more fuel economy out of your car
Jeep Liberty should notice a decent increase in fuel economy, between 2-5%. It will make the car easier to drive requiring less fuel to do the same job
maybe
In some case it is just for looks as they are not true dual exhaust systems. In other cases they are for improved performance and are true dual exhaust systems. On most V6 or V8 cars they do improve performance. On a 4 cylinder they do very little to improve performance.
It is often used to improve performance, fuel economy or emissions.
There are several ways. First step would be to change your jets, air cleaner assembly and exhaust. Or do like I did and replace your carburetor with a performance unit with an upgraded air cleaner assembly and install an aftermarket exhaust system of some kind.
improve the economy
How much money do you want to spend? Mustangs are one of the top cars for aftermarket performance parts. You can do things as simple as changing the exhaust all the way up to replacing the engine with a high performance create motor.
It will improve the flow of exhaust coming from your engine. This will give you better gas milleage, more get up and go and will last longer. All of these things can also increase your cars value.
There are a wide variety of tools that can improve a scooters mobility and performance, including but not limited to better exhaust, more efficient fuels systems, and more efficiently designed engines.
More cam, better exhaust, smaller torque convertor, more rear gear.
Swap out your stock ecu chip with a high performance one it can increase hp and mpg.
There are several factors that can improve the economy. The biggest factor that can improve and economy is a low unemployment factor. When unemployment is falling the economy usually improves.
Change the exhaust, the air flow and the gearing. You can get a 2-stroke Vino going 60 mph. . .