I first installed this product on a 2000 Jeep Wrangler and loved the extra power and fuel savings. I recently bought one for my Honda Ridgeline and love the extra low end torque and fuel savings. I found that one installed on the Jeep experienced the whistle, but the one on the Honda is quite. Excellent Product!
But, at least in my '07 Honda Pilot, the new leaner air/fuel calculations have changed the shift points under full acceleration (5200 before vs 5000rpms now) The pull is stronger now, but you just know there's another 200rpms at the end that never come. And that's where a late model V6 makes it's torque. Between 3000 and 5500 rpms. All in all though, a good investment. Make sure you combine it with a cold air intake system or you're not going to see much difference. You can also have your ECM (computer) reprogrammed/re-flashed to regain those lost rpms, but make sure it doesn't void the warranty. Too busy having fun with the power right now to measure MPG's. Maybe in a couple months....