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Old 07-10-2011, 03:48 PM   #1 (permalink)
EcoModding Lurker
Join Date: Jul 2011
Location: Michigan
Posts: 18

The Able Sable - '00 Mercury Sable GS
90 day: 22.76 mpg (US)

Dory - '07 Ford Freestyle Limited AWD
90 day: 24.1 mpg (US)

Cora - '07 Toyota Corolla CE
90 day: 41.43 mpg (US)

Fat Fit - '10 Honda Fit
90 day: 50.43 mpg (US)

Prius - '14 Toyota Prius Three
90 day: 58.49 mpg (US)
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EOC/Flat Towing on Automatic Transmission

I would love to increase my FE by EOC, but I wouldn't do that to save a little money when it might require a transmission rebuild due to damage. So, I wanted to find out if it would be safe to EOC my auto. I learned that:

1) Manual transmissions can EOC and be flat towed
2) Most (but not all) automatic transmissions should not be EOC/flat towed without the installation of an electric oil pump.

Hopefully I am right on here for automatic transmissions. If I am not, please correct me. When running, the engine pumps the automatic transmission oil and keeps it lubricated. When off, the engine does not pump automatic transmission oil and parts of the transmission will not be lubricated. In the case of flat towing an automatic transmission (and possibly EOC, although I haven't read this anywhere), the car must have an electric oil pump to keep the transmission properly lubricated.

So, for me with my automatic transmission:
Engine off coasting ($2,300 transmission rebuild) < Engine ON coasting (reduction in FE)

I am very curious to hear others thoughts on this.

If you are currently trying to figure this out in your situation, I have read that many owners manuals specify if the vehicle can be flat towed. Further, if it can be flat towed, then you can EOC.

Dinghy Guide and Dinghy Towing < A list of vehicles that can be flat towed.

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