Air Bear

anybody, have any performance, fuel mileage, improvement figures, going from stock 3 inch exhaust to 4 inch exhaust with straight pipe or straight thru muffler.

CTD NUT

While some here claim a power gain, don't expect much of a change when installing 4" exhaust on a stock truck........the real gain to be had is a notable egt reduction - especially when running at fueling levels beyond stock. The real power gains come from additional fueling - 4" exhaust simply lets the motor accept higher fueling levels before egt becomes an issue. Some claim a mileage gain but I noticed no change on either one of my trucks......a good straight-through muffler will perform the same as a straight pipe.

Tommy93w350

I bought a 4" system from WarpSpeed, good system, easy to install, and best price on the internet, but, I lost mpg. The 4" gave a quick trottle response and a little more power. A lot louder in the cab even with the muffler.
Honestly, I wish I had my 3" back on my truck.

Supermod56

I tossed the stock pipe the 2nd day I had the truck and went to a 4". Never had gauges on it stock so I don't know how much it helped the EGT's, but it does. What I did notice is it lets the turbo spool faster. A must-have if you do any fueling mods, or you will burn it down.

Tom

Air Bear

Just as I suspected, I shouldn't listen to salesman and their hype about all the advantages of 4 inch exhaust. I do know that a straight pipe will give you more torque and a cone megaphone at the end of the exhaust pipe creating some restriction and back pressure is better for higher rpm power. well, I will drive it and keep track of fuel mileage. thanks

2002 quad cab 24v line-x 295x16 4inch stainless

Gotlift01

Nope it's pretty much just a good sales gimmic to get you to buy! The only thing that I really noticed was faster spool up and less lag like SUPERMOD56 said, and lower EGT's. I couldn't tell a darn bit of difference in mileage, maybe because I couldn't keep my foot out of it