Radio or no radio?
 

Watched a video about a world record attempt on the Lands End to John O' Groats run in a petrol car. They achieved 94 mpg in a Honda Jazz.
https://www.theaa.com/about-us/newsr...record-attempt
One of the first things they say, after no AC and windows closed, was "and definitely no radio". So just how big an impact does using the radio have on fuel efficiency? I could see a problem if you have a 1200 watt sub woofer and 8 x 100 watt active speakers, but does a normal car radio make that much difference?

After alternator, battery and equipment efficiency losses, you're probably looking at roughly 2:1 watts in vs watts out. Most aftermarket head units can put out ~50 watts peak, ~20 watts continuous. If we assume 100 watts constant draw at the crank to run the radio, that's about ~15% of 1HP, or maybe 1-2% fuel economy worst-case in most cars.

In my G1 I have a 640w amp and a sub on top of an aftermarket head unit, and generally speaking it disappears into background noise (lol) and I can still hit 90-100mpg blasting the radio. In theory I could be drawing up to 2HP at the crank for maybe a 20% loss in ecnomy, but I'd probably destroy my ears getting anywhere near that. Normal listening volume, even with an amplifier, there's no easily discernible economy loss.

What he said.

In my old Insight Turtle I not only had the radio cranked, I also had the rear camera hooked up through the DVD player running all the time and I still averaged over 70 mpg in it. I also averaged way over 70 mpg in Ron Burgundy with the radio blasting and the AC on most days.

In my Volt I always have the radio and AC on (ECO mode), and never notice much of a drop. I don't think the radio draws enough to worry about unless you have a really weak battery or alternator

I suppose, if you are going for a world record, every little bit helps. I have written elsewhere about my poor highway mileage compared to city driving. The only time I use the radio/iPod is on the highway!

^^
The thing that strikes me is that I think people are overestimating how many watts their radio pulls during operation. Unless you're cranking the volume until the speakers crackle, it's not as much as all that. I wouldn't guess I'm ever running my radio at more than ten watts' output, thereabouts.

Then again, a lot of the time I'm listening to an audiobook on my personal MP3 player, at which point the issue becomes moot. Headphones and a wearable audio device means no watts at all to the radio except the barest whisper of a fraction of an amp to keep the clock on and retain the memory presets.

My audio system runs off a 16A fuse. That would, in theory, be up to 192 watts. So allowing headroom, no more than 100 watts. I have only two speakers (the S version for poor people), so a max of 50 watts. It is never played at full lick, so assuming heavy bass, no more than 40 watts. My sidelights use more than that! hardly a heavy load on the alternator.

Some people may eventually claim to drive better while listening to some music, but anyway, apart from not having too much impact over the fuel consumption, a portable radio or MP3 player and the phones are usually way lighter than a regular radio.

I think the difference in mood and concentration from listening to music is the actual issue, not the power draw of the radio. I would bet that I'm a more aggressive driver when blasting music than with the volume low or off.

Gotta have to agree on that matter, even though the apparently negligible power draw and weight of the radio and the speakers may not be totally disconsidered.


It might depend on what music you'd be listening.

They didn't remove the radio for their record attempt. Only switched it off - so the weight didn't come into it. Also, they had an adjudicator in the vehicle. Bet he weighed more than the radio did!

Everyone says that Classical music calms the savage beast\breast, but when I turned the radio to Classical when I drove a school bus, the kids were ready to riot. When other drivers put on loud rap, the students became docile.

I listen to Classical or Oldies when I drive--unless they are on commercial, pledge drive, or talking endlessly. Then I listen to whatever station does not yell at me.

Sure, but I was considering normal driving, not a record-breaking attempt.

It's not about the radio, these days the 'radio' is has a capacitive touch screen, GPS receiver, Bluetooth, HDMI/Wifi, a CPU that could have comfortably sent man to the moon in the 60's, cooling fans, amplified aerials, 6+ speakers, a sub and amp or two etc.

That's an not insignificant load when you add that all up. My 180W solar panel is just about enough to hold about 12.3v with the ignition and stereo on.

If you've got a single speaker AM unit, then that's different :thumbup:

We often call it a radio for tradition, but so many times they're now often mentioned as "multimedia central".


I was considering those portable radios. Usually lighter even than an old single-DIN car radio, and now with the availability of SD card slots or USB ports. And many of those can operate either with batteries or a 12V DC in.
https://sc02.alicdn.com/kf/HTB1NOqdN...rtable-12V.jpg

ha ha ha that sticker says a thousand wats. ��
suuuuuure it does

Even though it doesn't, it's not so bad at all, since the electric load would be lower in case it's being fed through the vehicle's own 12-volt power outlet :D

One option is to use good headphones&spotify. That's what i do. Because the radio channels here seem to produce pure garbage :D

At least in my experience, I wouldn't be concerned so much about the weight or power draw, but the slight distraction caused by the radio. If I were going for absolute max MPG then I would turn the radio off in order to focus better on my technique, so maybe that was part of it.

Probably it's even worse in Brazil

I have always been fond of "Garota de Ipanema." "Cotidiano" is good, too:

I was considering the contemporary stuff, not the Bossa Nova.


"Cotidiano" sucks, and so does its author (Chico Buarque).

You can't stop me from listening to it! In fact, I am going to listen to all of his other stuff now, too!

Well, not right now, I keep trying to convince myself to see if I am still enrolled in college!

Maybe you could try Djavan or Milton Nascimento. I don't like them either, but maybe you're gonna like.

I too have a Honda Jazz 2007! 1.3 i-dsi
Under light electrical load, it turns the alternator off. I can feel a difference in coast distance / time.

This usually happens under light electrical load, and low fan speed. Radio hardly uses any power in the jazz, i'm quite pleased. I think it's somewhat more efficient than a normal car, infact i've slept in the car with the radio on overnight and battery was hardly discharged (used voltmeter, i think on low volume you get more drain from the interior bootlamp).