How does the 2011, F 150 transmission work ? ......The transmission is assumed to be a double overdrive. Therefore, typically, 1:1 ratio is otherwise known as direct, is most efficient, has longer life expectancy and builds less heat.

With that said, first overdrive in a double overdrive transmission should be see less stress than second overdrive. That is, subject to available operator controls and robust remainder of the transmission case and components.

Higher axle ratio moves torque/work load from the axle gears, first to the transmission and then to the engine. Argument for higher ratio has been that the ring gear/pinion create less deflection, summarized to be more efficient and create a balanced design life for all components.

Point is, subject to a known transmission problem, the 3.15 locked to not exceed first overdrive would result in a final drive ratio similar to a lower axle ratio operated in double overdrive.

The operator would have finger tip access to lock into first overdrive. Second overdrive would be selected for non-towing/hauling, rolling hill, freeway driving.

That tranny would be screaming at full load. at 3.15 you would be retarded to get it unless you didnt tow or towed jet skis

I'm sure I qualify for the retarded part......Obviously, you know about gear ratio. The application; occasionally haul a few hundred pounds and a minor, unknown tow load.

The question remains; Can someone offer 3.15 insight ?

I dont know personally but my 2010 camaro has 3.43's with a little more horse and torque and hammers down. Cant image 3.15's in a truck without towng and a turbo that thing would be mean

sorry - no 3.15 insight here.

No one I know would be interested in this truck running that ratio.

UD

http://www.ford-trucks.com/forums/10...ace-clips.html
I found this 6.2 vs Ecoboost pretty enlightning.

Yeah I dont think so either. What would be the point you would have no torque.

23 Mpg is with a single cab, short bed, two wheel drive with 15 tires and 100% gasoline not this E10 crap they sell at the pumps.

True but if look most are claiming close to that highway

I'd like to see how well this smaller displacement gas engine under boost holds up towing for a couple years before committing to dropping that kind of coin on a unknown.