Poor coasting: why?

[Joggernot]

My coasting distance in the Accord increased considerably when I replaced the rear wheel bearings. Apparently they were going out and I hadn't noticed. Started arriving at the stop signs and lights going much faster than I normally did before the replacements.

[serialk11r]

Aside from aero and rolling resistance, I've found that some cars can have more drag from the transmission in neutral or clutch disengaged. More of a DCT wet clutch thing though, just throwing that out there.

[BabyDiesel]

Your Fiesta is an unfortunate fusion of low weight and high Cd, along with a CdA of 22-24 based on your measurements. None of which are good. But you don't bring a car to Ecomodder to keep it the same!

I'm reminded of a picture that Aerohead has posted on several threads. It details the Cd changes from different rear hatch slope angles. IIRC, your car might be along the highest Cd possible. I 'll see if he can post it on this thread.

In my 98 Escort, I did drag reduction to reduce the Cd from 0.33 down to 0.269. After coastdown testing, I stripped my entire interior except for my driver seat for cleaning. This was about 175 pounds lost (~80 kg). Immediately, my coasting distance plummeted! P&G was pointless and my points to start coasting on my trips meant nothing anymore. I added the weight back and the coasting improved, and overall mpg improved.

If you do a lot of highway driving, you might could add weight without much of a penalty. The coasting distance would improve even without aero mods.

[aerohead]

Here are some drag tables