- In general, expect a 2-5 percent increase in torque, horsepower, and fuel mileage.
- But, of course, the amount of power increase you’ll experience depends on how restrictive your stock exhaust is.
Thus, What mods increase mpg? Top Power and Mileage Mods You Can Do in a Day
- Cold-Air Intake. …
- After-Cat Exhaust. …
- Headers. …
- Distributor Upgrade/Ignition Timing. …
- Carburetor Swap. …
- Intake Manifold. …
- Ignition Coil/Plug Gap. …
- Fuel Injection.
Additionally Is a cat back exhaust loud? Straight through cat-back systems have mufflers of minimal size with fewer baffles. This creates a louder sound and a low amount of restriction.
What exhaust gives the most hp? The included SuperFlow mufflers have a straight-through design for a stronger sound and added power. Thanks to the high quality craftsmanship, Gibson exhaust systems are truly enduring and will serve you well for a long, long time. With this system, you will get the highest horsepower and torque at 1800-3000 rpm.
How do I make my exhaust crackle? 
How can I double my MPG?
Here’s what to do:
- Never drive above 45 mph. Yes, this includes highways. …
- Remove passenger side mirror. …
- Avoid braking and rapid acceleration. …
- Turn off engine at red lights. …
- Windows up/AC off. …
- Try to stay relaxed. …
- Legally draft when possible. …
- Overinflate tires by 10 percent.
What parts increase mpg?
Install These 4 Aftermarket Parts to Improve Your Gas Mileage
- High-Flow Cold Air Intake System. One of the first aftermarket parts you should consider when you’re aiming for better gas mileage is an air intake system. …
- Cat-Back Exhaust System. …
- Performance Chip or Tuner. …
- Performance Suspension Kits.
What parts help gas mileage?
Replace 5 car parts for better gas mileage
- If you’re unhappy with how much you are spending on gas, you may be able to save money by simply replacing car parts. …
- Mass air flow sensor. …
- Oxygen sensor. …
- Spark plugs. …
- Air filter. …
- Tires.
Will a cat back exhaust pass inspection?
The CAT must be approved for sale and use in California and posses an Executive Order number issued by the California Air Resources Board. A vehicle will not pass the smog check without having the correct catalytic converter installed.
Does a cat back exhaust add HP?
A cat-back exhaust system improves horsepower because it improves the car’s performance. Your vehicle doesn’t have to work as hard, and the flow of air is increased.
Is it illegal to have a cat back exhaust?
Catback exhaust systems are completely legal in the State of California because the modification starts after the catalytic converter and does not affect any of the emissions control components of your vehicle.
Are straight pipes with cats illegal?
According to Car Throttle this is usually due to the removal of the catalytic convertor and adding straight pipes, making it you guessed it; illegal.
Will a cat back exhaust void my warranty?
What about a cat back exhaust system? Since most high quality systems, at least those systems that are 50 state legal, are installed behind the catalytic converters, there should be no warranty concerns to other components, even emissions components.