Side mirror drag & effect on fuel economy - quantified

[Christ]

what about pulling both mirrors, but t then adding one of those fake shark fin antenna to the roof with a cam in it?

Probably still not a measurable difference either way, I bet.

[euromodder]

Originally Posted by GaspricesRhigh

Being as how it is only 3-6% of the entire drag.. I don't think it's justifiable to remove the mirrors. The hassle of even having retractable mirrors doesn't seem worth it. A mirror is a needed safety feature.

If it's legal to do so, and you replace it with a camera that functionally replaces the mirrors, why not ?

3-6% of the total drag is a lot.


The biggest gain in fuel efficiency is to be made when buying an efficient car.
Beyond that, it's the combination of small improvements like this that give you great mileage.
Singled-out, most mods are not really impressive.

[MetroMPG]

Good point, euromodder. If we only did the mods that returned big savings, we would have very few to choose from, and leave a lot (collectively) on the table.

Many of the mods I've done to my Firefly are in the 2% range, as near as I have been able to measure.

[Joenavy85]

many rain drops make a puddle, many puddles make a pond, many ponds make a lake, many lakes make an inland sea. little things add up, you might have a bunch of mods that only net 2-3% but if you have 10 that averages out to 20-30% improvement

[ecoxantia]

I feel a bit better about my 1.3% measured lower grille block now!

[NeilBlanchard]

I paid about $156 for two video cameras and two screens.

[Christ]

Even at $200, that's 50g fuel, so if I get 3% better fuel economy than my current 53mpg, that's brings me up to 54.5mpg.

53mpg * 50 = 2650
54.5 *50 = 2725, an extra 75 miles per tank.

75/50=1.5 gallons saved per tank based on previous mpg
50*1.5=33.3e tanks before I start saving from the mod's benefits.

This is with fuel at $4/gal. It's $4.25 or higher for me, so payback time is less.


Realistically, most p people only use 75% tank capacity between fills. Scale the figures accordingly.

[California98Civic]

I agree totally with the experienced voices chiming-in about small gains collectively making a big difference. I have been taking that kind of advice from this forum for weeks, and I am up to an average MPG in the mid-fifties (combined driving). I am using internal convex mirrors to replace both outside mirrors. I think that 3-6% savings is significant. Anyway, I am close to buying a spoon-type mirror to replace the drivers side, retractable on the freeway. That is only because of police, since it MIGHT not be legal in CA, where the law is vague as to whether the mirror must be outside on the driver's side. I will say with my two convex mirrors and modifications in my behavior as to how I check for lane changes, I believe there is no safety risk. I have no blind spots in my field of vision behind the car. In fact, I see more to the sides as well. But don't take my word for it. I give no legal advice or driving advice with this here email.

[euromodder]

Originally Posted by GaspricesRhigh

Only thing I would like to add is that a camera is expensive.

If you ever have to replace a heated, remotely adjustable mirror with built-in indicators, you'll wish they were as inexpensive as a camera

[orbywan]

I recently replaced the side mirrors on my 99 Saturn with side cameras, see photos. I also blocked off the grille and made covers for the headlight nacelles. All of those mods together have so far yielded a 16% increase, with the side mirror(s) removal accounting for about 5% of that.
I have side mirrors on the inside also, just in case a side cam fails. I'm getting comfortable with it all at this point. So far no overheating from the grille block with the A/C on. Next up are wheel covers and a belly pan.
I started to install an on demand hydrogen system on this car but found out when I installed the map adjuster and the EFIE 02 adjuster this computer does not take kindly to 'adjustments'. I've read since then the Saturn's ECU are one of the worst there is for tuning 'adjustments', so far I'd have to agree with them.
I disconnected the IAC, that seems to help a fair amount on the occasion I can coast a little. If I can find some info on how the IAC works exactly, I'd like to build an adjuster for it to control idle rpm better, like being able to dial in idle speed when the A/C is on.