I installed a Dynomax cat back system on my 2008 Ford Ranger 2.3L 4 Cylinder 5 Speed XLT Extended Cab Pickup. It came with an Ultra-Flo Dynomax stainless steel muffler that was great for around town. BUT on the freeway it started humming under ANY load (e.g. the gentlest grade change or cruise control requiring more speed). When I first heard this I thought my diff was starting to fail. It was extremely annoying and too loud to listen to music over exhaust resonance. Tried resonator head, deflectors etc. at highway speeds in 5th gear with no success. I found this Super Turbo to be exactly the same size which allowed me to keep the rest of the system. and it's great, the tiniest amount of pleasant exhaust rumble versus road noise, but NOT A GHOUL AT ALL. Perfect sound and good product.