I am interested to know what kind of mileage we should be expecting out of these new BOSS engines, hopefully a little better than my current 13 MPG on my 05 5.8L CC. Any thoughts or ideas?

 

How'd you get a 5.8 in a 05?

I'm sure you know it's 5.4, but I was just messing with you.

 

Lol, sorry on the typo, 5.4...

 

Very carefully.

 

been driving in the rain down here in texas for the last week, my mileage has been steady at 16.5 city/highway combo...

 

i got 22.5 during 300 miles of all highway driving out of my 07 cc......but then on the way back i ended up with 14 with bad weather....

 

First of all, as a disclaimer: I feel your pain on the gas issue.

This keeps coming up and it's starting to really drive me nuts! Modern engines are the most efficient gasoline engines ever designed. Period. They make as much power as possible, with as little loss to heat and friction as they can. For the most part, the same can be said for everything in our trucks.

The "Problem" is that it takes lots of energy to move heavy trucks down the road at decent velocities. My '07 Screw weighs just under 6,000 lbs with me in it. It is NOT going to do well on gas in the city, as starting and stopping nearly 3 tons takes lots of gas. Doesn't matter what engine they stuff in it. If they were to take the engine out of a Toyota Corolla(42 MPG highway) and stuffed it into an F150, it would not get much better mileage, but it would certainly go a whole lot slower.

Short of a miraculously efficient and totally different powerplant, no real truck will get "good" gas mileage compared to a car.

 

i do not think it will be able to move!!!

but i think the 6.2L will get around 16 mpg, then the 4.4L will be around 19(hopefully)

 

Hehe...you may be right!

Diesel is definitely an alternative I was not thinking of when I made my previous post. I'm just sick of people expecting car-like gas mileage for a full size truck!

 

I REALLY REALLY REALLY wanna see a 6spd trans in this thing!!

If nothing else it would make it more fun to drive and they would probably have to make less comprmises on gear spacing.
I had a 02 ranger edge with the 5 spd auto and that was the only thing that made it semi fun to drive kept the engine right in the power band all most no drop in rpms when it shifted

 

While I would enjoy driving a new Boss 6.2 inthe short term - in the long term I would rather drive a more efficient vehical. So.....

Actually, higher mileage is very possible, however is is going to take some rethinking and reunderstanding on the part of truck owners.

If today's engines are so efficient, how is it that in the early 80's you could buy a new half ton rated at 30 mpg on the hiway?

If todays engines are so efficient, how come my old 1986 F150 Supercab 4x4 with a AOD, 3.55 gears returned 22.8 mpg on a strickly hiway trip? Of course in mixed driving I do not get that kind of mileage, nor would I expect to.

To me it is very easy to get higher mileage that we are getting, cut the *horsepower in half, double the mileage. We simply, in my humble opinion, don't need trucks or cars with enough power to go 150+ mph, in a land where the maximum is 80 mph. Make the freeways in open areas unlimited as to top speed, then I would gladly drive a high horsepower rig, and gladly pay the price for fuel. Otherwise to me it is a waste of a good horespower producing engine. Good luck with this though in a culture that thinks speed kills.

Higher mileage might make it a bit less fun to drive - but then I don't get much thrill from sitting behind the wheel any more than I have to, or want to as in the case of wheelin, cruisin,etc. Life is far too short and I have too many other interests.

*or put a smaller displacement engine in, and supercharge it so you are not paying for filling 6 liters of fuel / air at low speeds, rather only say 4 liters of fuel and air (smaller engine, more mileage), but still able to produce a fair amount of power (and suck down the fuel) when you get on it. I would like this option the best!

Make my new F150 a diesel with 140 - 180 hp, gear it high, return 35 (easier in the state of Washington as most urban areas are limited to a max of 60mph, open areas are only at 70mph) on the hiway and I will be happy!

David

 

Yea thats never happening in the near future...

 

Where? www.fueleconomy.gov:

a 1985 F150 with the 4.9L I6, 3 speed auto is rated at 14 city, 15 Highway

Hell, for that matter, a 1985 F150 with the 351 V8, 3 speed auto is rated 11 city, 11 highway.

These are EPA figures, the same ones you see on the window sticker!

How much did a 1986 F150 weigh? Hard to find figures, but from what I can find, it weighs about 1,000 lbs LESS than my '07 Screw 4x4. On it's first highway trip, keeping the cruise at 67 MPH, it got 21.5 MPG. My truck has 3.73 gears and the 5.4L V8. This was hand calculated, starting from a full tank, using the amount of fuel the truck took when I filled it up. This on a truck that weighs 1,000 lbs more.

YES, IT IS MORE EFFICIENT.

My truck is rated at 300 HP with the 5.4L V8. When it's crusing the highway, it is NOT putting out 300 HP. It is putting out maybe 40-60 HP out...this is the power necessary to keep the truck up to speed. Put an engine in that is half the size, either it will downshift to produce that same 40-60 HP or it will lose speed. On top of that, that engine will have to work harder to keep up to speed, requiring the computer to enrichen the mixture, burning more inefficient just to maintain the speed.

My truck weighs 6,000 Lbs with me in it. A less powerful engine will NOT get better mileage. It's physically impossible for a substantial increase in mileage in a vehicle this big, unless you go with a diesel or some kind of new technology that is not available right now.

 

Sorry Tom, a smaller engine will get better fuel mileage overall. You are not only climbing hills, there are also times when you are going downhill, as well as flatland running. Even the 4.2 lite V-6 does not have to downshift for any of the later two senarios, and further, if it only takes 40-60 ho for your truck, then the V-6 would produce that just fine. heck, even a 4-cylinder would work fine.

You have to remember that a gasoline engine is most inefficient at low speeds, therefore, from pure physics standpoint, a smaller enigne running harder WILL get better mileage that a larger engine running slower.

Plus, a smaller engine, also as mentioned, will get better mileage in town as there are less "litres" to keep fed with not only "air, but also "fuel"

Please take the time to review basic stoichmetric fuel air ratios to confirm this.

I see that even the EPA estimates that you looked up also confirm that a smaller engine gets better mileage.

Now getting back to the early 80's fuel economy, I indeed remember quite clearly the ads from Chevrolet/GMC that there were introducing the first full size V-8 powered truck that was rated at 30 mpg hiway. The Corrosponding 6 Cylinder Ford was right behind in there advertising at 29mpg hiway.

Maybe I am wrong and it was the very late 70's ? However I know that I did not mention the mid eighties EPA estimates anywhere in my earlier post.

Please in the future, take the time to research a bit on the facts before you post a negative. I took the time....

So to review, yes, in truth, a smaller engine will get better fuel mileage. This is also proven by the fact that in the mid eighties, in truck fleets, we were getting almost 9 mpg from the 220hp Freightliners, at weights up to 80k.

Regards, David

 

Oh, and my old F150 scaled at 5600 lbs with me and my dog on board. There in only a 400lb difference.

Good guess though, I would have figured it weighed less too, but once I ran it over the scale, I was suprised.

Not sure how that changes the whole efficiency thing, as I returned 22.8 mpg to your 21.5 mpg at a weight of only 400 lbs less... ?

David