I was told buy a reliable source the the 4.5 that Gm is test is getting up to 35 mpg. Don't shot me that is what he said and I believe him. We will see when they come out, but that does sound good to me.

Mmm hmm, sounds perfect...we can only hope.

Per Charlie Freese GM engineer in the 10/08 issue of Diesel Power....

He would not give specific MPG mileage estimates, but Charlie stated that " We expect the 4.5L V-8 Duramax to deliver about 25% better fuel efficiency than a comparable powered gasoline engine under light load operation. However, when the truck is used for work (towing & hauling), its fuel efficiency advantage extends into the 40-70% range"

I was told buy a reliable source the the 4.5 that Gm is test is getting up to 35 mpg. Don't shot me that is what he said and I believe him. We will see when they come out, but that does sound good to me.
35mpg would be amazing, but I have a hard time believing that a roughly 6000+lb truck will get the same highway mpg as my wife's 2500lb 1.6L Honda Civic.

That would be great.

Regular cab, 2wd, 3.73 rearend or lower depending on what the offer and going 55, who knows?

That would be a dream come true, If GM produced that truck you would have a waiting list to buy them. That is actually something that will pencil out at upper $4's for diesel.
I can see 28mpg. You'll have to let us know if they de-tune them when they start to sell the trucks to the public. I don't think the big oil companies would be too happy if they made a truck that gets that milage and pulls like a freight train.

because the oil companies control the big 3???
Riiiiiight!!!:p:

thats incredible. The millage that blows away a Dodge Neon and the power of a semi. not really. but thats still incredible. Chevy pulls this off, and people are gonna be towing useless weight to SAVE fuel!

thats incredible. The millage that blows away a Dodge Neon and the power of a semi. not really. but thats still incredible. Chevy pulls this off, and people are gonna be towing useless weight to SAVE fuel!

Your understanding it wrong, unloaded they expect it to be 25% better than a gasser, if you loaded the gasser down and loaded the 4.5 down it would then do 40-70% better than the gasser for mileage. Not that it gets lets just say 20 mpg unloaded and 25 mpg loaded, which it sounds like is the way you understood it.

Your understanding it wrong, unloaded they expect it to be 25% better than a gasser, if you loaded the gasser down and loaded the 4.5 down it would then do 40-70% better than the gasser for mileage. Not that it gets lets just say 20 mpg unloaded and 25 mpg loaded, which it sounds like is the way you understood it.
yea im thinking 20-25 but i hope it can pull 35 mpg thats would be ba

I will give getting one some serious thought.

I heard from a good source 24-26 city 35-36 highway this was in a suburben 4x4 and I also was told that this thing kills the 2010 emmision laws. The bad news is it will be allalible in the suv first and they will not be putting them in any base models only lt .

x3 on th emilliage issue i didn't here city numbers but i have heard from a few people that it was expected to get over 30 highway

They'd need a more aerodynamic friendly design for 30mpg freeway.

my wife is so getting one of these when they come out...

hell she might get my truck and ill take it!!

EdZachery...
It's time for form to follow function. The truck should now evolve to do the payload with less wasted steel, more aero, and less weight if possible.

because the oil companies control the big 3???
Riiiiiight!!!:p:

Ignorance is bliss.

that would be great, my 08 impala with a 3.5L V6 will get 33 on a good day, but most days 27-28. I'm really missing the diesel power and fun, but everyday I get closer to getting another one. A full size vehicle pulling 30+ and i'm so there.

Your understanding it wrong, unloaded they expect it to be 25% better than a gasser, if you loaded the gasser down and loaded the 4.5 down it would then do 40-70% better than the gasser for mileage. Not that it gets lets just say 20 mpg unloaded and 25 mpg loaded, which it sounds like is the way you understood it.

ah! I see. Yup I sure got that mixed up. You hit that right on the nail. I was wondering how on earth the truck got better millage loaded than it did unloaded. thanks for the clear up. Still, mileage is incredible. I am sceptical of this a but, but to see it pulled off will realy reset the standard for other companys out there. Maybe the age of tiny "fuel efficent" gassers will end and people will drive this!:lol:

35mpg would be amazing, but I have a hard time believing that a roughly 6000+lb truck will get the same highway mpg as my wife's 2500lb 1.6L Honda Civic.


Read this article... Fuel mileage for a Diesel is much easier than for a gasser... Kind of an interesting read..... Honda Does it AGAIN! (http://news.cnet.com/8301-10784_3-9712548-7.html)

Read this article... Fuel mileage for a Diesel is much easier than for a gasser... Kind of an interesting read..... Honda Does it AGAIN! (http://news.cnet.com/8301-10784_3-9712548-7.html)

I agree that fuel mileage for a diesel is much easier than for a gasser because the diesel doesn't have near the pumping losses that a gasser has along with the higher energy content of the diesel fuel. And I hope that the 4.5L in a truck body will deliver 35mpg highway. But with 2.5-3x the weight, 3x the displacement, at least 2x the aero drag, and more rolling resistance from larger tires, it's tough to swallow similar mileage between a full size truck and a compact car.

Honestly, if they can get 35mpg out of a 4.5L, what are they doing wrong with the 6.6L becuase most everyone else is around half of that with the 6.6L. Sure there is a little more weight in the 3/4 ton and 1 tons vs the 4.5L half ton and the larger displacement of the 6.6 has more losses then the 4.5L, but 2x the mpg?

I just don't see 35mpg in a full size truck..... especially if the highway speed is in the 65-75mph range.

All we can do is wait and test the 4.5 ourselves. I'd definately be interested in 24+ city and over 30 hwy. If it wasn't for the Oil companies, I'm sure these trucks can get well over 30+. The old 6.5 turbo in a light duty 3/4 ton 2 wd was getting that kind of mileage.

I almost bought a 1990 K-5 blazer with 130K and the 6.2 diesel. (I regret it now) He bought the blazer brand new and drove it for every mile it had on it, and knew the machine inside-out. He consistently got 28mpg at 55-60 mph trips over average terrain, not flat like the desert. I would be shocked if the truck wasn't capable of close to mid 30's under the same conditions. The right gears, keeping the engine in it's sweet spot just chugging along it should be the shot in the arm GM needs.

hate to dig up a dead fish with the mileage issue, but do you guys think the EPA will rate the mileage figures lower than real world economy like they did with the VW Jetta TDI? I know just how quickly mileage on a diesel can drop if you get your foot in it, and vice versa.

Well winter milage is what i would like to see, it seems that i lose about 3-4 mpg in the winter.

I had a chance to drive a ck 900 test mule, the cals were just under 65%. All I can say is wow! This diesel is quit, smooth, and the performace was great. Now, as far as the mileage goes... I heard that they are having a tough time getting getting close to 25. Of course all that can change over the next year or so. The only thing I didn't like about the LMK is all the exhaust aftertreatment components, urea, scr, dpf, and Nox detections...... All of the exhaust aftertreatment is sure to raise the cost of the vehicle and doesn't help raise the MPG. Once again, thanks to the new EPA emission standards for 2010MY.

So, is now the time to start on a Urea, Nox, and DPF delete kit..... eh? :(

I never understood the need for such high hp/tq on the 4.5L. It has to hurt fuel economy and mpg's will be important for sales.

I was told buy a reliable source the the 4.5 that Gm is test is getting up to 35 mpg. Don't shot me that is what he said and I believe him. We will see when they come out, but that does sound good to me.
people always shoot the messenger, thanks for the info man, cant wait to take one for a drive.

people always shoot the messenger, thanks for the info man, cant wait to take one for a drive.

Speculation is, we may have to wait a LONG WHILE...I hope the talk of shelving the 4.5 isn't true.

I hope they can pull this off. If so, I think it would kick Toyota in the ASS!!!!! And I can't wait for that day.

hope that theres a gm left by then

I don't see why 35 MPG is hard to believe. I have a 4x4 Crew Cab 6.6L with a heavy shell that will do 21 MPG at 75 MPH. If I would drive it at 60-65 MPH it would likely do a little better. So why shouldn't a 4.5L do much better??

25-30 mpg sounds about right

35mpg would be amazing, but I have a hard time believing that a roughly 6000+lb truck will get the same highway mpg as my wife's 2500lb 1.6L Honda Civic.

I can pull a consistent 24mpg on highway with my 4x4 LBZ doing 55-60 on cruise using DuramaxTuner's Light Tow Tune. My 2500HD is considerably heavier and taller (i.e. more wind resistance) that a 1500. 35mpg might be a stretch but I could see an honest 30 out of the new 4.5L.

It will probably depend on the emission crap they load it up with. We all know they could make them with 30 or more mpg, but not with the laws the "dumbascraps" pass.

jb

I want one now!