Testing / Results

Dyno Testing - 

Where the lies meet the truth. We have found through dyno testing that our cat-back kits produce the largest HP and TQ gain in the exhaust industry and still have ZERO droning in the cab.

So how do we verify those numbers on every truck? We find a completely OEM truck, (exhaust, tune, air intake, and manifolds) just as it left the production line many years ago. We have dyno'd trucks with 300,000 miles and trucks with 2,000 miles on them.

When we strap the stock test on the wheel dyno we make 3 Pulls ensuring we have a good baseline data set to compare. Unstrap the truck remove the factory exhaust and install an MPI System (Cat-Back). We give the test vehicle an estimated 20 miles of road driving to allow the factory tune to relearn the short-term fuel trims with MPI Exhaust exhaust, then dyno the truck. Making 3 pulls as before to ensure a consistent number.

Bam, up to 30 HP Increase!

NOTE* All numbers are measured with a completely stock vehicle. Any aftermarket parts or non-OEM parts may alter the numbers. 

Do I Need a Tuner/Programmer?


All our numbers of hp and ft-lb gains are with zero tuning. A truck's computer monitors the exhaust temperatures with O2 sensors and air sensors to give your truck's engine the correct fuel it needs. When you replace your exhaust, it takes a couple of drive cycles for the truck computers to fully relearn the long-term fuel trims, the short-term will relearn the very first time the truck drives over 45 MPH with a new system. So the truck will adjust accordingly for the new system. 

MPG Testing - With trucks, we sample for MPG test we drive a 50-mile stretch of road, mostly interstate then a couple miles in town driving with a wide variety of different areas, some large hills, some long flats, a mix of everything. Filling up at the pump, drive the 50-mile test section, cruise set at 80 MPH, drive the 25 miles turn around drive back to the same pump, and fill up. We repeat this test 3 times to ensure a consistent number. Go back to the shop, change exhaust then repeat the same test 3 times. We always use the same 87 oct gas with testing dyno and MPG.   


2-4 MPG - Why is it a range vs a hard number? Every truck is a little different. Tires, bed covers, simply have too many variables.  Newer trucks will gain more MPG instantly vs older trucks since the computer systems are "smarter". Trucks with proper maintenance will gain more vs trucks without. We have fuel mileage trucks with 300,000, misfires, and bad cam phasers and still gained 1.98 vs stock. So we know all trucks will gain a minimum of 2 MPG vs stock.   





At MPI Exhaust, customers can expect experienced answers to their questions ranging from testing to fitment to installation. Our knowledgeable technicians are available to assist.