Flowmaster Super 40 Series Muffler Review

There are many who are considering purchasing an aftermarket muffler for their vehicle. There are plenty to choose from, all with their unique benefits and sound. I purchased the Flowmaster Super 40 series muffler. Flowmaster claims it to be one of their loudest high flow mufflers. According to Flowmastermufflers.com “The Super 40 has that ‘deep and powerful’ sound of the original 40 series but with all the performance benefits and low internal resonance of ‘Delta Flow technology’. I have to say I agree with the fact that it has a deep and powerful sound, however, the internal resonance is significant.

I put this muffler on a 2001 Toyota Tundra 4.7 liter V8. I ordered the muffler online and when it arrived I took it and the truck to a local muffler shop and had it installed. The shop simply cut the original muffler and installed a new one. The resonator was left alone. I also added a stainless steel tip. Since day 1, I have been very impressed by its sound.

Between .5 and 2 RPM the sound is very throaty and deep especially when I’m really into it, however as my RPMs increase above 2.5 the cockpit sound gets a bit lower and the revs from the engine replace the sound of the exhaust Still sounds great in my opinion, but not quite what I was expecting.

Performance-wise, I feel like I’ve lost a bit of low-end power. With high flow mufflers like this this can be common. The claimed horsepower gains are true, however the horsepower increase is at higher RPMs. The loss in low-end power is enough for me to notice, but not enough to make much of a difference. (I’m picky)

I have not noticed an increase in MPG. I was hoping it would, but it remained unchanged. (even with a K&N drop in air filter). I’m still getting between 16 and 18 MPG.

Advantage:

* Deep throaty sound inside and outside the cabin.

* Good price.

* Increased power (high RPM).

Cons:

* It is not a stainless steel construction, but it is painted. After several months of use, the beautiful black paint has almost completely burned off.

* Around 65 to 70 mph, there is an inner resonance that I just don’t like. It goes about 72 mph, so it’s not a big deal. I liked it at first, but it gets annoying after a while.

Overall the Flowmaster Super 40 is a great product. I really like the sound of this muffler. It is deep and smooth. It is not harsh and “scandalous”. It produces a powerful sound and really lets you hear the beast that is the 4.7 liter i-force. It is one of the best Toyota aftermarket parts I have ever purchased.