[Drivingforfun]

I admit I'm not mechanically knowledgeable but I was wondering something yesterday after looking at an exhaust pipe that wasn't attached to a car, and noticing the 2 outlets are connected to the same place

What's the reason for cars having more than one exhaust outlet pipe at the back? Is it just considered "sporty" looking?

Do 2+ smaller outlets produce a "nicer" sound than one big one? Or is it for legal reasons, like a single outlet has a maximum legal size so they just put lots on?

In a world where car manufacturers genuinely remove cupholders to save weight for emissions/economy tests, I can't see the justification in the extra metal so it must surely serve a practical purpose

Thanks!

[Beelzebub]

Originally Posted by Drivingforfun

What's the reason for cars having more than one exhaust outlet pipe at the back? Is it just considered "sporty" looking?

There is no right answer. Some are functional, some cosmetic.

[olduser]

Exhaust systems are a complex subject.
At its very basic, it's just a pipe to get rid of exhausted products of combustion.

A RR Merlin aircraft engine just had 12 short stubs at first, but exhaust gasses were getting into cockpits (not good) so different stubs were tried, the outcome was (after some changes in shape) the Spitfire of the day was (I think) 20 - 30 MPH faster using the thrust from the exhaust like a jet engine.

Exhaust on cars, designed properly use the energy of the flowing gasses to suck exhaust out of each cylinder, improving the engines power but at low revs it can force exhaust gasses into the cylinders decreasing emissions, exhaust engines produce sound, this can be, and is tuned to what the designer considers a sexy sound. The silencers main job is to reduce the volume of the sound.

Twin pipes were/are an easy solution to getting the exhaust from a V engine, this shows two pipes at the rear, the simplest would by one each side but they can be side by side.
V type engines suggest big engines, which suggest power, so twin pipes suggest power.
So, the reason a car with a single exhaust pipe but with a bit fixed on to show two pipes is trying to kid you it's powerful that's all.

If you are of a certain age, you will remember falsies, I'd best leave it at that.😮

[Mark07]

There are plenty of cars with fake exhausts to make them look extra sporty. If you poke a stick into them more than a few inches, you'll find out which are real or not.

[olduser]

In my youth, it was potato's we pushed up exhaust pipes but potatoes were cheap then...

[Rolebama]

Certainly with most multi-cylinder engines, individual exhausts, one per cylinder, are better for power, but, a single exhaust system is generally better for torque. But, their are other factors involved. Cam configuration and timing, inlet system, ignition timing, valve and cylinder head design all play a part. Manufacturers tend to compromise between power, torque and economy so any off the production line engine can be improved upon in any or all of these factors.