MPG Run--1995 Aspire SE

[TominMO]

Increasingly strict safety regulations make them heavier.

Yeah, and the Rio had a 1.6 motor IIRC, to compensate for the extra weight.
Edit: just did a search, the 1st-gen Rio had a 96-HP 1.5L motor, and weighed 2103 lbs (probably dry). Makes me wonder about engine compatibility with Festy trannies. Or Kia engine/trans swaps into a Festy with some other axles.

[qroger]

Mileage Variables

49 is good, but I've gotten 52.1 MPG @ 60 MPH with my Festy, 58.5 @ 55, 62.5 @ 45. You can see a consistent trend here regarding speed,

If I remember correctly from my days of riding a 90cc Bike, wind resistance doesn't really arise till 55mph or so. If I remember an exposure to math that I once had, air resistance increases with speed by an exponential amount rather than a linear amount: Double the speed, cube the air resistance, I think.

It is doubly strange that the Aspire which is new enough to benefit from Aerodynamic knowledge isn't more slippery, since the Festiva looks as aerodynamic as a Hummer.
Qroger

[TominMO]

If I remember correctly from my days of riding a 90cc Bike, wind resistance doesn't really arise till 55mph or so. If I remember an exposure to math that I once had, air resistance increases with speed by an exponential amount rather than a linear amount: Double the speed, cube the air resistance, I think.

It is doubly strange that the Aspire which is new enough to benefit from Aerodynamic knowledge isn't more slippery, since the Festiva looks as aerodynamic as a Hummer.
Qroger

The Aspire's about 300 lbs heavier, and the tires I have on it are 185/70x13. Stockers were 165s, so there's more drag there.

As to wind resistance, it depends on the slipperyness of the specific vehicle. A Festiva with a large door attached vertically to the front of it would run into a resistance issue at a lot lower speed than a stock one. 55 sounds a little high as the average speed at which air resistance matters; I suspect it's more like 45.

Looking at the two cars side by side along the hood/windshield area, the Aspire hood is more smoothly rounded and the windshield has more rake (slope backwards), so it looks more aerodynamic. But as narrow as both cars are, there is just not much surface area for the air to interact with, which lessens the differences in drag.