While the 2016 Prius has an upgraded luggage compartment, it still has not utilise the huge amounts of bonus space below the trunk sill like many other cars do (these have enough space to easily accommodate a full size spare tire, the rear compartment is actually flush with the bottom of the car. If you don't carry a spare tire you can fit significant amounts of luggage in this space) The 2016 Prius has a huge muffler square under the luggage compartment taking a lot of space in a car that uses space so efficiently otherwise. The Gen 3 seems to have had a much smaller muffler located more off center. Anybody know the reason for size and location of the muffler?
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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...
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.
