Using DFCO to increase your MPG - Toyota Yaris Forums

Yaris Hilton · 09-01-2009, 12:22 AM

Yes, it's the DFCO. Yes, it slows down the car faster than coasting in neutral, because the car's momentum is spinning the engine with no power being generated, just drag. It's not meant for increasing gas mileage, but for eliminating exhaust emissions while the car is coasting. If it's coasting down a steep enough hill to overcome the drag, you're saving gas over having the engine still running at idle power. If you're on level ground, you'll save gas whenever you're coasting toward a stop and would be using the brakes sooner without it. But it won't always save gas. Under conditions where it makes you slow more than you want to and you have to give it more gas to make it up, you may lose a bit.

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09-01-2009, 12:22 AM	#10
Yaris Hilton Half a Bubble Off Plumb Drives: 2009 Yaris Sedan Join Date: Mar 2009 Location: Bristol, Tennessee, USA Posts: 1,593	Yes, it's the DFCO. Yes, it slows down the car faster than coasting in neutral, because the car's momentum is spinning the engine with no power being generated, just drag. It's not meant for increasing gas mileage, but for eliminating exhaust emissions while the car is coasting. If it's coasting down a steep enough hill to overcome the drag, you're saving gas over having the engine still running at idle power. If you're on level ground, you'll save gas whenever you're coasting toward a stop and would be using the brakes sooner without it. But it won't always save gas. Under conditions where it makes you slow more than you want to and you have to give it more gas to make it up, you may lose a bit.