Placebo Effect
 

I was wondering whether sometimes mods have a placebo effect. For example, I recently switched to some lower weight synthetic oil, which has resulted in some record-breaking mileage for me. I'm wondering though whether it's really all the oil or not. Could it be that the oil does provide some benefit, but much of the benefit comes from me looking at my mileage display and thinking, "Wow, this is a really good day today, maybe if I really focus, I can break another personal record." So, for example, maybe the oil provides a 5% improvement, and my increased focus provides another 5% (maybe?).

I'm not sure if there's really any way to prove or disprove this. Anyone else thought about potential "placebo effects"?

All the time. Practically need a double blind test to avoid it.

It might not be related, and/or the difference may be within testing noise.

You often read on performance sites that placing magnets next to the fuel lines increased both power and fuel economy, for example.

Diesel_Dave -

I only make hard claims on three things, driving style, one-size-up tires and my taller 5th gear. Recently I've also had some really good tanks after switching from 91 to 87 octane and slightly modifying my side skirts. But in the background there is also the possibility of warmer weather and a change in the gas blend.

One thing I think happens a lot is that someone joins this group and makes a mod at the same time they are improving their driving style for MPG. They make the mod, are more attentive during the mod, and improve their MPG as a virtue of changing the way they drive. Now, which helped more, the driving style or the mod?

CarloSW2

more fillups, the better for the average

Yeah, I think there is certainly a placebo component.

You mentioned positive thinking over a potentially record-breaking tank. Sometimes the reverse happens too, when you get behind an erratic vehicle, or hit a few extra lights on your commute. It's like you know it's going to be lousy no matter how hard you try.

Although it's not magical, I think it has everything to do with focusing - or not focusing - on success.

The placebo effect should be listed as a real mpg saving technique, it causes the driver to drive at his utmost best.
Vortex generators could improve everyone's mpg.
Magnets and acetone can make you drive smarter !

Yes, but not small fills as any particular data point is more affected by fill variation.

But is the effect permanent? How soon will it take for the old habits to return without a conscious effort to to change them?

And a good tank reinforces the driving habits caused by the placebo effect, thus "proving" that the change resulted in better mileage.

How about a new mileage technique: Using Placebo (TM) to improve driving skills.