Size of rear muffler - giving away cargo space

welcome! i have no idea, perhaps to make the car quieter?

 

One of my biggest disappointments was the lack of the sub floor bonus space in my 2019 Prius. I came up with a little solution. Check it out if you're interested!
Custom rear cargo spacer for camping, hidden cargo area, etc. | PriusChat

 

The size is to make the exhaust quiet. The location is as far to the rear as possible so that any holes in the exhaust will be in front of the muffler so you hear them and don't die from a silent exhaust leak under the cabin. -- if anyone is still wondering.

 

Give me a Gen3 style front-to-rear muffler off to the right and make room for a spare on all models. That Gen4 muffler is a huge waste of space.

 

Is the muffler the same on all gen 4 levels? I suspect so, and ONE US gen 4 level has the temp spare. Internationally, some even have full size spare, as evidenced by mention in the Owner's Manual.

I don't think the muffler configuration is the reason all the levels don't have spare. More likely just cutting costs, and/or trying to keep weight down, keep the vehicle in an easier mpg testing class.

Everything BUT consumer benefit, btw.

Geez I'm in a foul mood today...

 

Questions dealing with man almost always come down to this: money.

 

I do not know if it is specific to this car, but when Toyota uses variable valve timing they change the timing to move any detonation (ie knock) into the exhaust manifold. It protects the engine from any damage. Then you need a bonus sized muffler to cancel the noise. But I do not know if they do this on a hybrid engine.

 

Priuses with AWD have a slightly smaller muffler, painted black for some reason.

While one(?) trim now has a spare tire, the floorpan is the same for all models, and no it is not as deep as the previous platform which had space for a spare tire and under-floor storage above that.

This is probably the correct answer. With a larger muffler in the center, no plastic diffuser panel is needed. If the cost of that panel is greater than the cost difference between a smaller muffler and the larger one, then--money saved.

However, other TNGA cars such as the Corolla use a plastic diffuser and offset, smaller muffler. It probably depends on the program goals for cost, weight, and aerodynamic efficiency and it just shook out this way for the Prius vs. Corolla muffler arrangement.