Hi I've been wanting to add a sub and amp to my 17 Prime. On Crutchfield and talking to their reps they keep telling me not to add an amp that has a fuse rating above 30. How much damage could be done by doing this? I see others have added high fuse rated amps. Just curious what the downside is by adding the amp? Does it affect the MPG? Thank you!
A 30A fuse on 12 volts would consume max 360W. Let's assume you're using 200W on average. The car is rated at 16,100 Wh/100 km. If you drove at 100 km/h then in one hour you would consume 16,100 Wh for driving and 200 W for music. The amp would lead to approx. a 1.2% reduction in efficiency. Overly simplistic calculation though... just rough order of magnitude. I would be more worried about straining the 12v battery. They are known to easily die. Even if the traction battery has charge, you won't be able to start the car if the 12v battery is low or dead. The 12v batteries are not cheap to replace (as I recently found out lol)
I'm over at the regular prius side and my car does fine with a remote start with a mile range remote sensor as well as a compact amp with a 10" underseat sub and 65 watt speakers. MPG is not affected for my regular prius. I don't know what the talk is about a 30amp fuse since with an amp, you would place your own fuse directly to the battery from the amp/sub. You should be fine if you keep a conservative system, but these cars won't probably handle huge amount of watts.
