Replacement Exhaust/muffler 97 Metro

[RedRocket321]

Just bought a 1997 Geo Metro 3 Cyl, 5 spd, 128,000. The muffler needs replacing. The question that I am posting is should I go with a stock muffler (autozone) or go with a muffler from (flomaster, cherryboom,etc). I realy do not care what tone comes out of the exhaust but would prefer more of a rumble instead of the whine I am getting now if possible. I can live with whatever sound as long as the mpg is there.
I have read that the stock mufflers give too much back pressure and hurt fuel economy and that the performance mufflers reduce backpressure and help to increase mpg. Could I get some suggestions on what type of muffler and possibly model numbers so I could do the right thing for the Red Rocket.

[MetroMPG]

On the topic of exhaust tuning, I'm no expert (I just play one on TV).

But this is what I've read from people who know more than I do: opening up your exhaust is what you do if you want to improve high RPM performance - something you're not going to be doing if you're driving for efficiency.

Doing that may hurt low RPM performance (torque).

For best MPG, you want low end torque, and for that a standard exhaust with stock "restriction" is best.

[RedRocket321]

Thanks Captain Slow. The stock muffler it is. You are already saving me $$$. What other things should I look into for improving mileage?
I see your gas mileage and WOW I want to know what mods you did to achieve such high numbers?
The car has I own has 128,000 on it. Are there certain things that have issues with the Metros I need to keep an eye on?

[Katmandu]

Originally Posted by MetroMPG

For best MPG, you want low end torque, and for that a standard exhaust with stock "restriction" is best.

TOO much restriction is NOT a good thing for efficiency and/or power.

Too much exhaust restriction forces back-pressure on your pistons causing your engine to work HARDER. Therefore reducing efficiency.

[Frank Lee]

Dooya think the factory boys put too much restriction in?

[Katmandu]

Originally Posted by Frank Lee

Dooya think the factory boys put too much restriction in?

Of course they do.

[Johnny Mullet]

I experimented with my exhaust a few times and one thing about these 3 cylinder engines is they are very loud without the proper muffler or cat. I used a replacement muffler made by Walker and it was like $69.00. I enjoy a quiet ride. That "pissed off hornet" sound gets very annoying after awhile.

[Katmandu]

Originally Posted by Johnny Mullet

I experimented with my exhaust a few times and one thing about these 3 cylinder engines is they are very loud without the proper muffler or cat. I used a replacement muffler made by Walker and it was like $69.00. I enjoy a quiet ride.

Did the Walker make any difference efficiency/power wise ?

[Johnny Mullet]

No, it was like a stock replacement.

[MetroMPG]

Originally Posted by Katmandu

Of course they do.

I'm not aware of any credible/reliable evidence that a free flowing exhaust will improve fuel efficiency at the engine speeds most eco-drivers operate.

From Fuel saving gadgets - a professional engineer's view

Another frequent argument is that the intake and exhaust systems of "stock" engines are too restrictive, that is to say it takes a lot of power just to suck the air in and blow the exhaust out. By reducing this loss, not only is power increased, but fuel economy gets better as well. In theory there is a hint of truth in that, but in practice the difference between a "stock" and aftermarket performance exhaust or intake system only really makes itself felt at times of maximum gas flow (full throttle, maximum engine speed - or close to it). Under normal crusing conditions the losses in even the standard system are so low that the effect on economy is vanishingly small.