So, to start, here is the article-

http://www.motortrend.com/roadtests/...est/index.html

A few things I saw of note there-

1.) Their conclusions on the eco seem to be in line with most of what I have been reading here. Eco offers plenty of power or the potential for great fuel economy, but not both at the same time.

2.) If you are towing, you should most likely be opting for one of the v8's if fuel economy is a concern. As has been discussed here, driving around with the turbos spooled all the time makes for lousy fuel economy.

3.) Speaking of the 5.0, motortrend writes . Can we please finally put this argument to bed. The 5.4 was a great motor, it was just old and cannot keep up with the new 5.0.


Reading the entire article is worthwhile to gain a bit of perspective of all 4 motors in relation to one another. Definitely a good read.

 

Thanks for the link. It was a good read.

 

Very good review. Wonder why the ecoboost was only a 2wd?

 

It was an ok article but mostly personal opinion and very little facts. They say things like this:

But the truth is they never hooked up a trailer to any of the trucks. Now if they had performed a real test of loaded fuel mileage and posted the results it would be a completely different story. Both of the V8 have to be worked harder to produce their power. In all the miles I have driven the harder I push the pedal the lower my mileage goes. Also, most turbo motors use extra fuel when under a lot of boost to cool the incoming air charge and cool the cylinder temps. The EB is a DI motor and uses the fuel much more efficiently than an EFI + turbo set up would. I suspect the EB gets much better mileage under a load then most people expect.

 

It was a decent article. As was pointed out, a bit of speculation is in there without actual testing to back it up. That is why I like pickuptrucks.com. They have done so much more testing on these trucks including long distance towing.

I probably need to stop reading these because it does make me want to trade my 10 for an 11 model truck with the 5.0. Fortunately, cooler heads prevail here because I can't afford to do that. I've also just spent some cash on my truck to improve it a bit. I may be in trouble if my dad ends up with a new F-150 to replace his 2000 Silverado. He wants the 5.0 and I can't stand the thought of him having that over my 4.6. I keep trying to convince him that all he needs is a 3.7 which is plenty to haul his 14 foot flatbed and a couple motorcycles. Something tells me he isn't buying it (even though the 3.7 is all he needs).

 

I see where you are going, but PickupTrucks.com I believe DID do this test and it only got like 5-9 mpg while towing a (I forget the length/weight) trailer up the rocky mountains

 

I think I also read that and the weight was 9k+ and there wasn't another truck there to compare it to. I am certain a naturally aspirated motor would never match the EB running through the Rockies.

Another point of view, it takes certain amount of power to move something from a dead stop to a given speed. A load doesn't care how this power is made 4, 6 or 8 cylinders are all the same at this point. A gallon of gas only has so much power in it. It doesn't care how many cylinders it is poured into either, it still has the same potential energy. So we have a required amount of work and a specified amount of potential energy available, the only variable would be the efficiency of the power plant. We know the EB is more efficient than the 5.0 or 6.2 when unloaded. We also know that both of these motors must be worked harder to make the same power as the EB. The EB is DI so under boost it is much less inclined to dump fuel into the motor to cool it. So explain to my how it suddenly uses so much more fuel that the less efficient motors once a load is on the back?

 

3.5 refers to the amount of air it takes to fill the cylinders at 1 atmosphere, when you hit 14.7 psi of boost you have just bumped the pressure up to 2 atmosphere and are stuffing right around 7.0 liters of air into the motor. When you up the air you have to up the fuel also, since a 5.0 never sees a positive pressure it can only take up to 5.0 liters of air and therefore only needs x amount of fuel to keep the A/f ratio correct. Since the 3.5 at 14psi of boost can take in 7.0 liters of air it will need x amount of fuel to keep the ratio correct and therefore require more fuel at high boost. That is very simplified, and its much more involved than that but you get the general idea.

 

If I remember correctly, both the 5.0 and 3.5 got close to the same numbers towing 9k+ trailer in the mountains.

Kevin

 

I agree but you left off the second half of the equation, they take in this much air per crank revolution. So from the graph in the article the 5.0 makes max torque at ~4500 RPM or 22500 l/min. The EB makes the same amount of torque at 2200RPM or 15400 l/m. The load is going to see the same ~280 ft-lb either way. That is assuming the EB is making near max boost at 2200 RPM. You can not compare the displacement alone when the torque curves are that far apart on these two motors.

If the same test was ran in the Rockies the EB would completely trash any of the gas motors. It can force more air in where as the N/A motors are stuck panting and wheezing.

 

Trust me I am not arguing, you just asked how it was possible for a more efficient motor to get worse mileage and I figured I would explain how its possible.

 

No arguments here, I know the EB can use the gas when you wail on it. Mine shows between 5-10 when I run WOT through the gears. But that is right about what my old 5.4s would do under the same conditions but making a whole lot more power. The comparison here was the 5.0 vs the EB pulling a trailer. When you compare how hard you have to push the 5.0 to make the same power as the EB I have a very hard time thinking it would use less gas to do the same thing.