With 600 miles on the truck, I calculated my overall fuel mileage so far. Most of this was highway driving though I did get a little heavy footed checking out the power. My average was 14.1 mpg. I hope that as the engine gets broken in this will go up a little.

 

I was just wondering what axle ratio you have in your truck....is is the 3.55 or 3.73? Thanks.

 

3.73

 

If you change the engine oil to synthetic you will get a little better fuel economy out of your rig. I don't know how or why this occurs, I just know that it does work.

 

Is your truck a 4x4, regular cab, super cab, supercrew? What do you think of your truck so far?

Thanks

 

Big sherm's overall average seems to be about right. I'm getting around 17 to 18 on the freeway at 70 MPH. In the city it is around 14 to 15. About the mileage advertised considering the trucks are not broken in yet.

I've noticed a big difference in mileage depending on how smoothly you drive the truck. The cruise control, even around town, increases it by 15 to 20%. When I let others drive the truck, the mileage really tanks, when I drive it is in between.

I do not know if this is a function of the electronic throttle, or just, pure weight. Also, the electronic throttle makes the truck feel a little sluggish because the power delivery is perfectly linear and smooth. However, the power is there when you romp it, in spades.

A neighbor just picked up a Navigator and is getting 9 to 10 MPG. When Ford adapts this 5.4 engine and systems over to the other vehicles in the line up it will improve Ford's entire line up.

~~~^~~~

04 5.4 Lariat Supercab 4x2

 

Hay bigsherm you said you have tested the power of the new 5.4 did you try to roach the tires. I have heard you can't. I thought the 3.73 rear end would make it easier.

 

Mine is a 4x4 supercab. I have tried to smoke the tires and it will not do it. Not on dry level pavement in a straight line. Not yet anyway, I hope the aftermarket will hurry up. I need magnaflow!

 

thanx for the info. I can't believe this motor really has 300 horse power and even more torque. if it did really have that kind of power it would have no problem smokeing the tires. especially sense there is not that much weight over the rear wheels. don't get me wrong I am not ditsing this engine because I have ordered me a FX4 with it in it. I just think ford is giveing us false info about it. I will be curious to see what happens when someone who gets this engine and puts it on a dino to see what it really packs. if no one else dose I think I will whan I get it. don't get me wrong I do believe this is a powerful engine but if it had the power ford claims it has it would be easy to roach the tires. I used to think it had all the power I would need. but it is now clear I will have to do aftermarket mods to give it some more power. I don't have plans for going arround roaching the tires all the time but do think it should have the power to do so.

 

seeing as how someone brought up the axle ratios maybe you could help me out here. I'm not that well informed on trucks and their numbers (i'm not of a car man myself, but steadily found myself getting in to trucks and after 2 years I finally need a full-size truck so i'm going with the FX4... but anyway, what exactly is the difference between the 3.55 Axle and the 3.73... which is better and why? I want to know because the better one is the one I'm going to get, along with the 35.7 gallon tank upgrade because if your numbers are right at 14mpg that's almost 500 miles on a 35 gallon tank hehe... so it'll cost more to fill up, but it'll last longer as well...

 

Check this thread for info on axle ratios...

https://www.f150online.com/forums/sh...highlight=axle

 

thanks dude i appreciate that

 

It does seem odd that the tires won't spin with the new engine. No one in their right mind is going to power brake a brand new truck that cost this much.

 

scooterjohn,

I am in my right mind, and I am going to smoke the tires on my new ride. At least enough to see if it will do it.

The idea is not to trash a new expensive truck, but you can't sleep @ night not knowing what 300hp will do. Can Ya?????

JMO

Have A Fantastic Dry Day. I live in Indy and we have had ENOUGH rain...heheheheh

freddy

 

I think the Electronic Trottle Control is preventing this form happening. Kinda like that Lexus LS 430 that when you floor it, the computer it has won't let burnout the tires. But that's just me.