Originally Posted by duckman903

I have a left over 2011 F-150 Eboost screw with 3.31 rear just turned 3,000 miles traded in my 07 sport trac with 4.6 V8 and 3.73 rear, with the sport I'd average 16 to 19 MPG that thing would haul a** , so I stopped at my dealers and was just looking not buying until they ran the numbers and my payments would be less, I'm really impressed with my F-150 had one before but it couldn't hold a candle to this one , just screwing around this morning and wanted to see what it would do pulled out from a stop 3/4 of a mile of empty road in front of me at about 15 MPH punched it when I saw almost 5 grand on the tach noticed that it was still in second gear and was doing over 70 got on the brakes and drove normally the rest of the way home. I love this truck, haven't had a chance to try it with my big trailer yet. They should not be allowed to sell this truck without a posi rear in it.

Originally Posted by ericnottelin

What weight trailer do you plan on towing with it. And yes, would love to hear how it tows.

Originally Posted by duckman903

It seems like you haven't been to New England, from my house to the center of town which is about 2 miles down hill there is an elevation difference of 250 feet . its not a lot but I'm at about 1,100 above sea level. When I leave my house every thing is either up the hill or down.

Originally Posted by ericnottelin

I believe he was referring to the differential. As i the HD payload does not come with a locking rear end but and open rear axle. But Price you do bring up a good question. I would like to know the answer as well.

Originally Posted by ericnottelin

I believe he was referring to the differential. As i the HD payload does not come with a locking rear end but and open rear axle. But Price you do bring up a good question. I would like to know the answer as well.

Originally Posted by ericnottelin

WOW, nice review. Just FYI, if that thing does have the open diff 3.31 then that truck will be really fuel efficient. A 5.0 with 3.73 (heck an eco boost with 3.73) will never compete in fuel economy. But, comparatively, the rental you are currently driving has a max tow rating of 8100 lbs. The same motor with the max tow package (including 3.73 gears) has a max tow rating of 11,200 lbs. To compare it to your 5.0l (with 3.55 and tow package) has a max tow rating of 9500 lbs.

So, your 5.0l truck will actually tow more than the rental because of the gearing. Incidentally, the Lariat you test drove (with the max tow package) will tow more than all of the others. Incidentally, the fuel mileage will drop down significantly with each gearing change.

Additionally, the difference in torque numbers between the 5.0l and the 3.5L between 1500 and 2000 RPMs (which is the majority of us who are trying to increase MPGs try and stay) is as follows: The 5.0l starts out at approximately 212 ft/lbs (1500 RPMs) and climbs to about 240 ft/lbs (at 2000 RPMs). The 3.5L starts out at approximately 225 ft/lbs (at 1500 RPMs) and climes to approximately 290 ft/lbs (at 2000 RPMs). So the 5.0l gains approximately 28 ft/lbs of torque in that 500 RPM range comparatively the 3.5L gains approximately 65 ft/lbs of torque with in the same 500 RPM range. This is where most of us operate (especially driving up and down those hilly roads ). As you can see not only is the 3.5L running at a higher torque rating for the normal cruising range, but it also climbs even higher throughout this specific range. This is why (even with that low 3.31 rear end) the eco boost will out perform the 5.0L in this area and why the torque numbers are so important. So when your traveling at 65 - 70 mph down your favorite hilly road and wonder why the eco boost doesn't have to down shift from 6th to maintain that speed. Or when you are moderately accelerating to get to interstate speed, and your 3.5l also stays in 6th gear, you can credit the torque curve the twin turbos provide.

Please don't think I'm bashing the 5.0l because I have been researching both engines and both have my respect. But where we drive them the most (1500 - 2000 RPMs) the torquey little 3.5l will always out perform the 5.0L. But the 5.0L will play catch up (to a point) when allowed to downshift and get into it's higher torque range.

I tried to attach two pics depicting the hp and torque curves of both the 3.5l and 5.0L as measure by a truck magazine that was comparing the two motors in identical trucks. But, I could not find how to link the pics from my computer

Hope this is helpful.

Eric

Originally Posted by jcb206

Actually a 5.0 with 5.55 rear end has a 7700 lb tow rating. His 5.0 is a little lower that an Ecoboost 3.31 (8100 lbs). You have to get the 3.73 rear end in the 5.0 to get the 9300 lb rating.

2012 Ford F-150 | View Towing Specifications | Ford.com