Ok so I posted a review of a test drivwe a few weeks ago I had with a brand new Lariat, EcoBoost, Crew Cab, Short Box, 3.73. Anyway took my truck back in to the shop this morning for slip/yoke-bump and shudder that happens 1-2 seconds in the drivetrain after a full stop.

This time they gave me a '12 Crew Cab, 4x4, EcoBoost with 3300 miles on the clock to drive provided by the on-site rental outfit. I tried to show my poker face as best as possible when they pulled the truck around, but inside I was like this

Ok I will cut to the chase and save you the cool story. First things first I have no idea what rear-end is in this thing, I will post the door tag so if anyone with more knowledge than I wold care to decipher the codes and let us know that would be great.

When they handed the keys over the truck had been sitting all night, so I fired it up cold. Still super quiet just like the Lariat I drove a few weeks ago but this truck had a slightly louder motor starting cold. I could hear more ticking than the other truck but no more than what I hear from my 5.0L when she cold starts. Also it appears you can hear the turbos sort of whine at first until the idle comes down after it is warm. Kind of cool but a little different too??

The cool thing about getting this rental is that there is no salesman riding along so & I didn't really give the brand new Lariat all the beans so to speak because well it was a brand new truck someone would eventually buy. A rental on the otherhand lives a life equivallent to a ***** (can I say that? if no mods please feel free to remove comment) so therefore I don't feel quilty.

Again just like the Lariat I drove before, low speed driving say 5-10 or 20 miles per hour or lets just say at parking lot speeds seems to require more input than my 5.0L. After that I think I can confirm there is slightly more torque. Also not sure if someone has played with the air-box on this truck but everytime I come off the gas be it aggressive throttle input or light I get a wooooosh, pssst , woooshhh, psst from the engine bay? I believe it's the waste-gates opening and closing. I didn't notice this on the Lariat I drove a few weeks prior but perhaps Lariats have more sound padding in between the sheetmetal?? Either way it sounds sort of cool but It sounds like something I would get sick of after a short time.

Once I got out of the lot I headed for the freeway and decided to take the long super hilly route home and drive it on some of the steep hills I drive my 5.0L on everyday for a more aqurate comparrison. First up was getting on to the short on-ramp (Or what I call the death on-ramp) I call it that because it's super short and if you are not driving something that can get out of it's own way you will get crushed by traffic moving 75-85. As Soon as I hit the merge a big rig was coming up fast so I had to put the hammer down. There was a brief bog just before the trans kicked down but once it did the truck instantly knuckled down with power to spare.

Once out on the freeway I set the cruise for the next 4-5 miles just to see how quiet & composed the truck was. again pretty uneventful and quiet just as expected. Then as the traffic lightened up I pretty much had an open highway as far as I could see. Put my foot into it from about 68 to get a better feel of the passing ability and sure enough this thing to go pretty nice, I would say it probably would edge out my 5.0L here but just barely. I was also suprised to note the trucks fuel cut is surprisingly 5 mph higher than my 5.0L? weird being that my 5.0L is a 2wd on street rated Michelins versus a slightly higher 4x4 on taller more Off-road oriented rubber?

Anyway next test was the 6% grade, I wanted to see if I could hold the truck at 70 mph without kicking down. My 5.0L will actually kick down 3/4 up the hill from 6th to 5th. The Eco held 6th the entire way up the hill awesome. I then got off the freeway got some coffe, re-set the mpg meter and took it easy about 12 miles back home, some country roads and light in town.

I was surprised that the mpg meter was telling me I was getting roughly 16-17 driving in town, my 5.0L would be reading 13-14 under the same circumstances. Also during my casual drive back home I decided to take note of some of the differences between the '11 & '12. First off the windshield wipers are a different shape, didn't get a chance to try them out but the ones on my '11 work pretty good as is. It also felt like I was driving a pretty "stripped" truck. No Sync controls, no productivity screen, no lumbar or hight adj seat, was also suprised it didn't have the manual feature on the shifter? I thought that was standard with the 6-speed?

Another difference were that eventhough this truck was a lot more stripped than my '11 XLT-Chrome plus conv package it had tweaters on the hinge post. The sound from the stereo was about on par with my replacement Apline speakers, but slightly more crisp due to the nice factory tweeters? The stereo was identical to mine though so hard to say. all I know is the speakers that came with my truck were junk.

(Same old F-150 quirkiness) This truck had only 3300 miles on it but had the same old Slip-Yoke/Bump that I am dealing with on my truck right now. It didn't do it every time, perhaps 1/5 stops. Also it clunked pretty good when say you slow from 30 mph to 20 then get back on the gas easy "clunk" also every so often when slowing to a stop there was a shudder in the drivetrain. The brakes seemed a bit firmer than mine but I might just be imagining this, I do know Ford increased the rear brake size slightly in '12 so who knows.

I also noticed this truck had a "one-piece" drive-shaft that looked thicker & aluminum compared to the two piece located in the center by a slip/yoke and carrier bearing on my truck (Same wheelbase eventhough mine is a supercab) Did Ford change to a one piece for '12? Even if not sure if I want it since I can still feel the slip-yoke/ bump on this rental.

I also notice the EcoBoost had an extra resonator looking thing just in front of the muffler? My '11 5.0L doesn't have this, the last '11 EcoBoost I looked under had the exact same exhaust plumbing as my 5.0L so they must have changed this too??

Anyway I will have this truck for the next day and will be taking it easy to see what the real mpgs are and will report back after it's all said and done. So far I like the truck, but deffinately miss the cool V8 sound from my 5.0L thanks for reading.



Here is the door tag if anyone knows how to tell what axle is in this thing?

 

My '11 EB has the resonator in front of the muffler.

3.31 open diff.

 

Nice write up sir.

 

Awesome thanks, what on the tag tells you the rear end? Just curious for the future. The 3.31 rear explains why this truck is not as punchy when you are just driving around in a parking lot or at low speeds. It also feels like there is a dead spot just like my 5L in third gear mild throttle going up hill.

Seamed like the Ecoboost I drove with 3.73 was pretty linear throught the rev range no matter what the situation was. Still not bad performance for 3.31 I would not hesitate to order one if I was going to commute in this thing. Also really good mpg compared to 3.73 rear, I can see why such the wide spread in responses with mpg's on these trucks.

 

Sweet man. My old man just got a 4x4 Eboost Screw XLT 3.73. 1000 miles on it and i seen hes been averaging 18.5 mixed driving. And after a fuel up running 60mph for about 50 miles and a few stops the computer was showing 20.5 mpg average. not going to lie, ours is a winner.

Nice write up.

 

My dad sent me these for the '11's but I've found it applicable to my son's '07 as well so these codes are probably pretty consistent through the years. F-150 axle codes Vehicle Rear Axle Ratio Non-limited Slip Rear Axle Code Limited-slip Rear Axle Code F-150 3.15 15 A5 3.31 27 Not Available 3.55 19 H9 3.73 26 B6 3.73E N/A L6 4.10E N/A L4 Found either on the door or pillar post.

 

F-150 axle codes

Vehicle Rear Axle Ratio Non-limited Slip Rear Axle Code Limited-slip Rear Axle Code

F-150 3.15 15 A5
3.31 27 Not Available
3.55 19 H9
3.73 26 B6
3.73E N/A L6
4.10E N/A L4


Found either on the door or pillar post.

 

That didn't work either time I tried to cut and paste it, but you get the idea. First code is usually open diff and second code (usually with a letter) is limited slip.

 

Also, the "E" codes are for the e-locker.

 

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

 

Well said, dealer called said I need a new drive-shaft. Anyway went and picked up my 5L and admit I has glad to be back in my truck but also have to admit that while the 5L is extremely fun to drive with the V8 & sound of the motor etc.. I had a lot of fun driving this rental Eco. It is really weird how you just mash the throttle and the truck takes off with almost no noise. It was like I had stealth mode or something. When you mash the throttle on the 5L it is sometimes embarassing but cool at the same time as everyone around you knows your giving it the beans.

At the end of the day the Eco was so much easier to drive though. I got the feeling at some instances the motor in both cases is limited by the trans & gearing. There was one point where I was on it and the trans up-shifted well before the redline so to speak and I was thinking really (I didn't want it to do that) it feels like just as the afterburner lights off the trans up-shifts the truck I'm sure this could be fixed with a tuner, but lets face it we don't normally drive like this everyday anyway.

I only wish I could have hooked the truck up to a trailer to really see how this thing works. Oddly enough the rental company most of taken the OEM trailer hitch off the trucks, I think they had three Eco's in stock/ fleet at the time I rented mine and none had hitches. They also had one 3.7L and I was somewhat interested in trying that out actually since I have effectively driven almost every combo of the current F-150 except the 6.2L & 3.7.

 

Thanks for the great evaluation of your experiences with these new trucks. They were thorough and informative. Also thank you to the folks who contributed to the thread with extra information and/or clarification. This is what this forum is all about!

-Craig

 

As you know my truck has t he open 3.31 axles. I hauled 2 cubic yards of composte / top soil mix yesterday and aside from the truck being overloaded, the engine acted like the bed was empty. No sweat at all.

That's why I've been paying attention to all the posts on here concerning gear ratios and basically not saying anything. The eco with a 3.31 is nothing to sneeze at.

If you take notice of the superduty line-up, many 6.7L powered F-250's are coming with 3.31 axles rather than 3.55's, 3.73's etc. And, the still have 12000-14000 pound tow ratings.

 

They order them without the tow package. This means no hitch, no trailer wires, and no Select Shift (manual control on shifter). also means no aux. trans cooler and no radiator upgrade.

why on earth they would even bother to make a truck without the tow package is beyond me, but there are a few roaming around.

also, that "dead spot" you felt in 3rd gear is the Torque converter locking up about 1/2 way through 3rd. kind of annoying because it is so noticable.

 

You can ORDER them with the basic tow package (selector transmission, hitch, upgraded radiator and trans cooler) and get what ever your gear ratio you prefer. But it won't have the MAX tow package which adds the larger mirrors and 3.73 gears. You can even order the larger outside mirrors and have the dealer install them (at $450 for the set). It all depends on what you want to do with the truck.

If it was my daily driver that i would occasionally tow (or haul heavy loads with) then I would absolutely go with the shorter gears and with the standard tow packages. But I mostly tow with mine (we will be using the truck to tow a camper/toy hauler) and going to different camping areas in the mountains. So, I would benefit more from the better towing gears.

Don't forget, towing and hauling on flat ground is one thing. Towing up mountainous roads will tax a truck a lot more.

Hope this helps.

Eric