Just bought a 2014 Mirage 5-speed (got 57.4 mpg on the 70 mi. trip home)

[sendler]

Extra mass is a way to use an over powered engine in a range (90% throttle) that is closer to it's peak efficiency.

[radiantthought]

He lives in Florida, like me. I can tell you that we don't really have hills here much. Unless he lives up in the panhandle area near the Alabama border, they have a few hills that way.

[Fat Charlie]

If you have good instrumentation, you'll find that you're almost never on really level ground. "Hill" means one thing to regular people, something entirely different here.

[MetroMPG]

Has anyone documented this in testing? The Flea doesn't have enough power to make even high-speed P&G worthwhile, never mind adding mass!

[radiantthought]

Here are some topographical heat maps of every state in the country. Florida is the flattest state in the country, and it's so flat that its variations in elevation are only 1/3 that of the next flattest state, Illinois. (~350ft maximum variation vs. ~950ft maximum variation)

Having said that, I always try to exploit the little inclines and notice a pretty sizable difference in efficiency even when going up our shallow grades.

[sendler]

Originally Posted by MetroMPG

Has anyone documented this in testing? The Flea doesn't have enough power to make even high-speed P&G worthwhile, never mind adding mass!

Applicable to normal road vehicles and motorcycles which are generally quite overpowered.

[3dplane]

I carry about 100lb of tools back there simply because the mirage is so light that the first time I tried my usual calibrated hill coastdown, I was horrified that I had to re-accelerate right in the middle of the run that my old now retired 94 mazda protege could coast in one shot.

Granted this was the bone stock brand new mirage. It is a little better now.

I could say hauling a little extra mass justifies for me to EOC! Without it (and the other mods) it would be almost pointless to shut her off just to have to rebump in a few seconds.

So maybe if the gained coasting distance does not outweigh the added fuel necessary to accelerate the higher mass, the ability to EOC might tip the scales in favor of MPG?

Yeah there are no real hills in north central FL but there are still variations in terrain elevation that can be used to an advantage.