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Old 09-27-2014, 03:11 PM   #16 (permalink)
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Join Date: May 2010
Location: Texas Coast, close to Houston
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getto - '02 Volkswagen Jetta GLS TDI
90 day: 53.82 mpg (US)
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Originally Posted by mechman600 View Post
I think you know the answer to that!

Be aware that if you are trying to coast, DFCO should be used as a last resort. Why? It all comes down to engine speed. In order to DFCO, the revs have to be above 1500, which takes considerable more energy than idling at 700. Sure, no fuel is being used during DFCO, but it still requires energy, which is provided by the kinetic energy of your coasting vehicle, which was previously provided by gasoline (accelerating up to speed). You can feel the energy loss - the way the vehicle decelerates quicker when you are in DFCO vs neutral coasting.

While it is neat to see DFCO appear on your ScanGauge, the general consensus around here is that if you want the most efficient coast, you do it in neutral, engine idling. Yes, it is still burning fuel, but your vehicle will coast much much further in neutral, and the engine will only need to turn at idle speed. And if the coast is timed correctly, it will actually provide a net savings over DFCO in the end.

Many like myself take it once step further will a kill switch. Long coasts with zero fuel make it even better!
and increase speed allowing a longer coast......
i have an Ultraguage, and love it. only way i am able to achieve the numbers i get. also, really easy to reset values after a fill up. and, cost 70.00 shipped.
FOR SALE: 02 TDI Jetta- 5 sp: Cooper CS5 at 50 psi, UltraGauge, ventectomy, rear air shocks, mufflerectomy, LED plate light, upper fiberglass grille block, front lower pan, front fairing.
93 Chevy CrewCab 6.5 TurboDiesel, GearVendor OverDrive, 4L80 w/ TCI controls. Now DailyDriver

Last edited by deejaaa; 09-27-2014 at 08:48 PM..
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