Experience with upgraded stereo affecting mileage?

I added a 200W powered subwoofer to my 2010 (see thread here http://priuschat.com/forums/gen-iii-2010-prius-audio-electronics/64433-2010-prius-jbl-powered-subwoofer-install-pics-instructions.html#post890232). I only had one tank of gas to compare to before installing it, averaging 5.0 l/100k (47 MPG), and after install I am getting 4.4l/100k (53.5 MPG). Now I'm sure most of the change in my MPG has come from learning how to drive a Prius more effectively but the sub sure doesn't seem to have noticeably increased my consumption despite being turned up full bore most of the time! :rockon:

 

Unless you go nuts I highly doubt you'll even be able to quantify the difference without serious data collection and experimentation. I see more variability with weather and driving conditions than I do with or without my stereo active. I've tried on a few occasions to disconnect the power to my very large amplifiers and I may have saw an increase in MPG but on other occasions I got less MPG. So I said to hell with it and just turned up the toons and drove. 1900 watts continuous power in a GenII.

http://priuschat.com/forums/gen-ii-...iamond-audio-midranges-installed-finally.html

http://priuschat.com/forums/gen-ii-...alth-install-aftermarket-stereo-in-prius.html

 

As an electrical engineer, I agree with F8L's post. You have to go really nuts with power before you will notice any mileage hit. A bigger issue may be idle draw when the car is off. The Prius has a very small 12V battery. Make sure any added equipment has a very modest power draw when off, or you will soon find yourself with a dead battery.

There have been some reported cases where stereo nuts have installed very large systems that exceeded the capacity of the 12V system while running. In these cases the 12V battery was slowly discharged during normal operation. Obviously these were *very* powerful systems.

Tom

 

<Raises hand>

Yup. I've done it a few times. I sometimes forget to turn the system off while driving around and just let the 12v battery recharge. I've walked out to my car the next day and found the 12v dead an I required a jump to get it started again. I finally swapped to an Optima Yellowtop battery this year. This is rarely a problem and usually only occured when I got a new Reggaeton CD and would run around blasting the system pretty hard during 90%+ of each trip I took. This never allows the change for the 12v battery to fully recharge during driving.

 

I think that you have just solved the "lack of noise" problem being a hazard to pedestrians!

All Prius automobiles should have s 200W subwoofer as standard equipment. As a safety feature, the car should play a Polka at full volume any time the car is standing still or going less than 30 mph.

Keith

 

Also an electrical engineer, I usually chime in with the additional comment: If one were to put in an amplifier large enough, one could exceed the capacity of the battery and pull enough demand on the inverter that would burnout the inverter. There are documented cases of guys putting amps so large in the autos they burn up the alternator. Some of these guys added a second alternator to get around this problem. Personally, anyone that puts that much audio power in the car should have his head examined - or should I say, will have his head examined when his hearing goes out and bruising of the brain sets in.

 

I've had 16yrs worth of loud stereo systems in all of my vehicles and my hearing and brain are doing great thank you. I've worked in the high end car audio industry since 1993.

 

WHAT??? WHAT DID YOU SAY??? SPEAK UP!!! :rockon:

My 500 watt amp, listening to some nice trashy Techno with the volume knob pegged at the top will actually slow the car down and cause the engine to labor. Sometimes I see sparks from under the back seat - might be the main batteries frying, I don't know.

ound:Actually, I cannot detect any change whatsoever from my upgraded stereo, except CONSIDERABLY better sound. Changing tires will have a much bigger effect on your mileage - I lost a couple of MPGs from the new tires I put on just before the 4th of July (but they work SO much better in every respect I don't mind).

 

On an energy level, 1 HP is about 746 Watts. So assuming you had a 746 Watt sound system and your mechanical to electrical conversion was 100% efficient (it isn't), it would take 1 HP to power your system.

I'm not sure about the conversion efficiency of the MG1 and MG2 when charging the traction battery or the conversion efficiency of the DC-DC converter that charges the 12V battery. A rough approximation might be 500 Watts of electrical power takes 1 HP from the engine.

Anyone know the efficiencies of these things?

Kris

 

It would be nice if you would evaluate the 2010 JBL system and recommend some reasonably priced upgrades. As you probably have read the rear speakers are all but detectable. It's not a bad sound but certainly does not sound like 8 speakers.

 

F8L's sig is a great list of upgrades. I'd love to compare it to mine, because I'm sure it's better. However, for the money I like the Infinity's I chose, but would select a different subwoofer if I had to do it over and a more modern amp with a remote control for the sub. F8L, what's your take on a good mid-priced system?