BearsRunner

Hey guy's, I just recently traded in my 4runner and bought myself a new Tacoma double cab 4X4. I was wondering what would be a better exhaust system would be mpg or power. I have always loved the flowmaster and have had it on my last two rigs. I have heard that Banks is making stuff for gas rigs, here's that link.
http://store.bankspower.com/Categori...8-ee8e24dbdf2f

nix4x4

The best exhaust is usually the factory setup.
If you want sound, use Magnaflow. DO NOT go with the TRD one, its junk

Elton

magnaflow is nice sounds good on my truck

William

You will gain nothing with just a muffler change.

And you wouldn't be able to gain MPG anyway. IF there was an increase in air flow (more exhaust flow out equals more air flow in) the extra flow would be compensated for by the fuel injection system by adding more fuel to go with the extra flow.

BearsRunner

So if I did go with something like the Banks exhaust, I would acually be sacrificing mpg because of the extra fuel that would be needed to compensate for the added air flow. I need to look up more info on exhaust flow, fuel to air ratios and stuff I think before I make my dicision. Any input you guy's have is great thanks.

I also had a 22RE P/U with a Flowmatser and a 3.slow 4Runner both stick shift and gained 2 to 5 mpg after install. I also put the AJ snorkel mod on both witch did incerease air flow. My new rig is an Auto, so I guess there is going to be a big difference in any mod that I do to it compared to muy old rigs.

William

If you notice, I said "IF there is an increase in air flow". I didn't say there would be an increase in flow.

It's very unlikely that the muffler is the most restrictive part of an engine's intake/exhaust. On most engines, the heads are where the most restriction is. But it can vary from engine to engine.

For the muffler to make an improvement, anything in the intake/exhaust that has less flow potential than the muffler would have to be modified to flow at least as much as the muffler.

Lets say the throttle body flows a maximum of 500 CFM (cubic feet per minute). If the muffler has the ability to flow 600 CFM, the maximum flow will still be 500 CFM. Why? Because the flow is the same throughout the whole intake/exhaust, and flow is still limited by the most restrictive part.

For that matter, lets say at half throttle the flow is 250 CFM, and you normally drive at half throttle. No modification that increases flow (except for forced induction) will help power at half throttle. Why? Because if you need 250 CFM to go a certain speed before a modification is done, you will still need 250 CFM after a modification is done to go that certain speed.

Any performance you might gain from an increase in flow will most likely be at or near full throttle, with the engine spinning at or near redline (which is when the engine is pumping the most air/exhaust). How often are you spinning the engine at redline at full throttle? Certainly not while driving normally.

If the muffler isn't the most restrictive part, installing a less restrictive muffler will make no performance improvement. What will most likely happen is you will gain noise with no gain in power.

And IF there is a gain in power, there would be no gain in fuel economy. You can't have both unless you install an engine that uses different technology that increases both power and MPG (such as variable valve timing, direct injection, etc.). Installing a different exhaust just doesn't do that.