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Unread 04-29-2014, 08:11 AM   #1
India_Actual
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Join Date: Apr 2014
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FDI and FDII Fuel Consumption Differences

I'm looking at buying a Patriot, and I'm researching all of the options. I was surprised to see such a steep drop in fuel efficiency when going up to the FDII. Why is that? The weight of the skid plates, crawl gears, and tow hooks don't seem like enough to drop the MPG that much. Is there something I'm missing?

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Unread 04-29-2014, 08:28 AM   #2
aroundincircles
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Final drive ratio.

to get the 19:1 crawl ratio, the FDII has been geared down. So say the CVT was an actual transmission with gears 1-6. The final drive makes it more like gears .25-4 compared to a FDI. (I know the CVT has no gears, I don't need that lecture again. I'm just trying to give an example) So while the top gears in the transmission are basically the same, (between the 6 speed auto and the cvt) the FDII has that one difference in the final drive.


In my old FDII patriot, at 65mph, I would run at about 2800-3000 rpm, in a FDI you would probably bet at close to 2000 rpm. That's a huge difference in fuel savings.
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Unread 04-29-2014, 11:31 AM   #3
India_Actual
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Oh, okay. It seems obvious now that you mention it. Thanks.
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Unread 04-30-2014, 07:08 AM   #4
IRSmart
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Quote:
Originally Posted by aroundincircles View Post
Final drive ratio.

to get the 19:1 crawl ratio, the FDII has been geared down. So say the CVT was an actual transmission with gears 1-6. The final drive makes it more like gears .25-4 compared to a FDI. (I know the CVT has no gears, I don't need that lecture again. I'm just trying to give an example) So while the top gears in the transmission are basically the same, (between the 6 speed auto and the cvt) the FDII has that one difference in the final drive.


In my old FDII patriot, at 65mph, I would run at about 2800-3000 rpm, in a FDI you would probably bet at close to 2000 rpm. That's a huge difference in fuel savings.
it's even more so noticeable now that the FD-I comes with the 6 speed automatic, raising the fuel economy over the old CVT.
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