I've never had that much problem with my cruise in neither my 02 nor my 07. It always keeps the speed pretty dang close.
Now my dad's 09 Tahoe totally different story. In fact any GM product I've been in will slow down to about 10 mph less then kick down and won't shift back up again till 5 mph over your set cruise point

 

Geez. I forgot to add my girlfriend's ram could be doing that because of the elevation. I've had 4 auto vehicles, 3 with cruise and none would drop more than 2 mph before downshifting. I keep telling her that her transmission missed automatic class lol. It's a 06 4x4 crew cab ram with a 4.7l v8 rated 235hp and 300lb-ft. With elevation it is really underpowered. First and 2nd gear aren't bad but her 3rd gear out of 5 is not even as powerful as my 4th in my f150. Her truck going up a certain hill will slow down in third but accelerate in 2nd. So it will just go back and forth from 2nd to 3rd. I can go up it in 4th and still accelerate up it.

 

Driving from MI to CA in '12 with my '11 5.0 I was averaging high 500's/low 600's to a tank. I never ran it close to empty but I did do 530 on a tank in the process and was just under 1/4. Averaged 17.4 whole trip at ~84mph. MPG was a little higher in IL/NB/eastern IA, then dropped to 14.9 in the mountains, but after getting through SLC into Nevada and eventually CA I was seeing 23.4. Ended up going through a tank in CA and averaged 20.
Haven't seen anywhere near that with my '13 eco, but haven't taken a dedicated road trip either.
Got off topic but I love the flexibility of the 36 gallon tank, it's definitely a bladder buster though.

 

I did get about 220 miles out of less than half a tank with nearly all of those cruising at 65 on relatively flat land. But once I got back into town and started driving how I usually do, I'm at 315 miles with a quarter or so left. It's the current tank and my best shot at hitting 400.

I have heard that manual keeping a vehicle at speed gets the best MPG, but I've gotta put in on cruise control to keep from speeding. I simply can't do it haha. My 06's cruise keeps me from dipping even 2 MPH below what it's set at when I'm going up and down hills in the central Texas hill country. It does spike the RPMs well above 2k going up a hill, but that's probably just a lot more noticeable because of how extremely loud my truck is. Other than the RPM spike where I'd be more gradual with it, no complaints on my cruise.

 

I generally don't get into these types of threads and I'm late to the party but here's some info for you on the 2.7. It's a clean sheet engine meaning it is not a version of the current EB 3.5 but a new engine. This one is like no other on the market. It uses a 2 piece block which is of CGI materials like the 6.7 Powerstroke. It has an upper block casting, a lower block casting which is a lot like a bed plate design of the big diesels. It comes with an Integrated Front Cover which will house the water pump, etc. and aluminum heads. In regards to metal parts, that's all folks. The rest is composite or in simple terms, plastic. The aluminum pistons will have high speed lower rings that have holes in them for faster oil drain. The aluminum rods are I Beam type that are offset. There are no typical wrist pins. There are cooling jets that constantly spray the bottoms of pistons to keep them cool. Exhaust ports have water jackets to cool exhaust gases. That lowers Nox and lets them run turbos a lot closer saving weight. Ford relies heavily on coatings in this engine to extend engine life. I doubt there will be any rebuilds as everything says this is a disposable engine. This will be Fords first start/stop engine in an F150 meaning when you put your foot on the brakes the engine turns off. When you release the brakes, the engine automatically restarts. I'm not sure that's a good thing in areas where A/C is all important. Certainly won't work around here. There is a bypass to that in 4x4 though. It's an interesting design but like I said, they rely a lot on coatings for start/stop feature and extending fuel mileage. Numbers I've heard are 320HP/ 340 ft lbs torque. Considering it's a 164 cubic inch engine, bore at 3.27, stroke a 3.27, compression at 10:1, it's going to be very busy under the hood to make the numbers. The transmission will also be busy keeping this little critter humming along in it's power range. Obviously from the design, this is going to be a fast running engine. With the axle ratios available, this engine might make 30 mpgs with a tail wind and the 3.31 gearset. All things weighed in, that's almost a hat trick.

 

Thanks for the info, Labnerd!

I want to say I've heard new start/stop vehicles not having any problems with the AC though. How, I have no idea.

 

Not sure but I think if you have the a/c on the vehicle won't shut off. Kinda makes me wonder about heat in the winter also.

 

30 mpg seems high to me. Just to pull the truck around this engine is going to have to work harder than the 5.0 or larger EB. I'd say 25 tops for practical mixed driving. Trucks are loaded most of the time so it will probably be lower than that. The truck will be 7 bills lighter, but that just means more payload. If you think this truck will get 30mpg, and you currently own a 2014 or older, I'd sell it now because it will be worthless. Most people would be able to justify a new truck if it got that much mpg. Do you guys realize how high 30mpg is? A Honda Civic is supposed to get 39mpg, but most don't break 36mpg. I was looking at a new Focus on the lot, and the sticker said 35mpg. There is only so much energy in a gallon of gas. Energy potential decreases as more ethanol is added.

 

My thoughts on this engine:

1. At best, the highway will improve a modest 1-3 mpg over the 3.5EB EPA estimated numbers.
2. In town, the on/off feature will really make a difference. I don't live in a large town, but it takes me 10-15 stoplights to get to the south side of town. I seem to hit a LOT of red lights. Out of 10 minutes driving, 3-5 are sitting at a red light.
3. I'm confident Ford will not put out an F150 that loses A/C or head while this feature is active. Electric A/C compressor? Larger coolant capacity? There are a few ways to provide 90 seconds of climate control while the engine is stopped. Will you be able to sit for 10 minutes at a train and expect A/C? Heck no, but people will still gripe about it.
4. I'm excited about trying this engine out. If it is the next generation of Ford's engine strategy, I'm confident it will be better, stronger, and will exceed our expectations.

 

Ford will put a switch in to disable the start/stop feature if you so choose.

 

Saw in a tweet that 2.7L will have performance of small V8 with 15% improvement in fuel economy. Not sure whether that means over the current small V8 (5.0) or over the 3.5 Ecoboost.

If it is over the 5.0 then that's 24 MPG highway, if its over the 3.5 Eco then its 25.3 MPG highway. Those are 4x2 numbers

Game changer? Discuss.

 

From what I've researched and heard the 2.7 will have the performance of a mid-range V8, not a small V8. It will have up to 20% improvement in fuel economy. The reports that I have read have suggested 25 to 29 mpg hwy.

 

My guess is that Ford will do everything possible to equal or top the numbers touted by Ram for their EcoDiesel. They will then use the equal mileage and much cheaper fuel cost in tons of ads.

 

Either way, it's gonna be a hell of a lot better than any other truck. Just the prospects of a full size truck with 320+ HP and 340+ TQ getting mileage like that blows my mind.

If it gets even within 2 or 3 MPG of the EcoDiesel, you'd have to be stupid to buy the Ram.

 

And those 15-20% numbers thrown around are apples to apples. That doesn't take into account the weight loss, the aero improvements, and any other fuel economy upgrades the new truck will have. I'm thinking we will see in the range of 27-29 MPG for the '15 with the 2.7L.