I may have over looked here and other places, but has anyone seen projected numbers for mpg for 4.5? Only thing that I know of is 25ish hwy that I over heard? And anyone think that they may offer an axel ratio other then the standard? Only thing with a lower axel ratio some of us may use the truck more then what it's intended for:D. Thanks in advance for the replies. All of ya do such a great job with questions and answers here!! I love this site so much my wife is jealous:whip: (Mission accomplised)

Also...food for thought, I hope with all these 1/2 ton diesel's coming out that it doesn't push up the demand on fuel to much, end result push up the $ on fuel:mad:

low 30's in a reg cab short bed without the towing package is what i've read.

that's better then what I've heard. I figured that it may do well on fuel.

.......and hey good luck in basic and an extra big THANKS for going into the armed forces. I'm sure you will come across a diesel engine or two there :)

I would have to see it to believe 30mpg. sure would be nice.

I would have to see it to believe 30mpg. sure would be nice.



X2. Unless they shape it like a bullet, seems hard to believe. but it'd be sweet if they do!

Back in the day I used to have a 2WD RC SWB 350 V8 that was lowered a bit and I regularly got 21-22mpg on the hwy with the cruise set at 70mph. Add 30% better mileage for a diesel and I would expect the 4.5 would get in the neighborhood of 27-28mpg based on the configuration. my 2cents

maybe

My old Lb7 can get 22 on the highway. No reason a truck weighing 1500 - 2000lbs less, more aerodynamic and efficient couldn't get 20-30% better. It is the emission equipment that is going to hurt the mileage. I would expect very close to 30 mpg. Even my dad's 4.8 half ton 2wd excab could get 22-23mpg. Diesel is about 20% better than gas so that gets it up to 27mpg.

Be nice to see 30 MPG out of the 4.5 L. I have seen 22.8 MPG out of my 6.6 so a good weight reduction and the right gearing in a 1/2 ton could get it close to the high 20's.

I agree, but usually its a trade up with something. Either with HP or Tq, But if It is just a weight and Ratio adjustment, that would be fantastic. The DIC on my truck say's 15.4 mpg so I am figuring on probably around 18 avg. I would love to see numbers as high as BIGR's 22.8.

low 30's in a reg cab short bed without the towing package is what i've read.

same here i rember reading somewhere of high 20s to low 30s is what there expecting

The 4.5 numbers seem like 95% of the HP and torque of the 6.6L.
Why not replace the 66 entirely?

The 4.5 numbers seem like 95% of the HP and torque of the 6.6L.
Why not replace the 66 entirely?

Even if the power was identical, or compare any two engines of similar power, longevity and load level are different considerations. I would venture that the 4.5 does not have the bearing area as a 6.6, making it a poorer choice for higher weight higher load applications. This gets into the difference between 200k, 500k and million mile engines.
To put it another way, the 6.6 likely has more headroom for developing more power. That is a two sided coin. An engine with less bearing area, lighter castings, weaker and lighter everything could be a great thing for light duty, or cars, and operate stock much closer to its all out limits. The 2.9 caddy has pressure monitoring in the cylinders - this can allow designer to tune to much tighter safety margins. Future smaller diesels will probably make better power ratios than even hotter Duramax's, but will not be built to handle the same loads.
IMHO, this is a similar difference between the Cummins and the Duramax, they really have different intentions that overlap in the middle.

Also looking for GVW's on the trucks and towing numbers
...it can't be too crazy if it still a 1500 series frame??

GM has always been a bit optimistic in their mileage estimation in my opinion. I will be very interested to see actual mileage in the various vehicles that it may be offered in.

As far as demand for fuel raising prices if more vehicles are offered with oil burners, diesel is already way higher than common sense says it should be. It is cheaper to produce than gasoline and the effect of the 500pm to ultra low sulfur diesel that many used to justify higher costs should be over. How is it that diesel has been much cheaper than gas historically and in the last year and a half is has completely flopped. Very irratating

I'm hoping for GM offering that gives us this. Just think 15 gallons of fuel and close to 1000 miles. How sweet would that be at $3.70 a gallon???

It could almost make me sell my motorcycle.

http://www.treehugger.com/files/2008/02/volkswagen_to_i.php

That is the main reason I am really wanting to see what the 4.5 will do. If it would do light towing and still make around 28 MPG, sign me up. There is no end in sight to the cost of fuel going up. Everyone is predicting $4 a gallon this summer. That makes it a lot more attractive to buy.
Just my 2cents.

I'm paying $3.90 here in CT, I wish GM would get this baby out into production along with some cars getting in the 45 mpg range. Has anyone heard any more talk on a diesel malibu?

Right now I'm doing a damn good job at supporting the families of Exxon/Mobil between my truck and my wifes Tahoe. Gotta keep their the kids mouths fed:).

it looks like they are getting a 2.9 from VM also. heard that it is going into the Colorado.

I make 14mpg in town/22mpg highway with a 96 1/2 ton 6.5 suburban w/ 3.42 gears. (indirect injected with crappy exhaust system, & factory 231k mile old worn injectors and a slight fuel leak somewhere) I'm sure with a good exhaust and new injectors that id be at 16/25-ish. The new 4.5 surely would make better mileage being direct injected and having newer technology. It for sure couldn't be any worse.

diesel may have a higher fuel tax, but the primary reason diesel costs significantly more is the demand for gasoline. so in theory if people who drive the half ton gassers trade them in gas demand goes down, and so does diesel because they don't have further refine the oil to gasoline it can stay as diesel

i don't see why a light 1/2ton with a duramax and the right gear ratio wouldn't get 30 m.p.g

I would be shocked if you couldn't get close to that in an ECSB on all hwy driving.

diesel may have a higher fuel tax, but the primary reason diesel costs significantly more is the demand for gasoline. so in theory if people who drive the half ton gassers trade them in gas demand goes down, and so does diesel because they don't have further refine the oil to gasoline it can stay as diesel


Very very good point....thanks

If they don't come out at 30mpg, give it week somebody will make a programmer that will & as far as demand I think a lot of people will get rid of or park there heavy poor milage diesels in favor of these.

im hoping its atleast 20-21 MPG city and 25-26 HWY. If it makes 520 TQ and gets 25-26 MPG on the highway i will really look into buying one of these.

If this thing can get 25 + mpg I have a hard time believing they will have any trouble selling these trucks

A friend of mine with a 2001 reg cab long bed 4X4 Dodge with the Cummins and 5spd got 25mpg on a reg basis and he claimed a best of 27mpg. These were all hand calculated figures and he never went above 70 mph. So i believe a 1/2 ton with newer technology and better design should get into the low 30's. My D-Max has gotten a best of 22mpg so far. I dont beleive you will ever see diesel more than .80-.90 cents more a gallon than gas either so just because gas is cheaper by the gallon doesnt mean you are saving money in the long run. What would you buy, a 1/2 ton gasser that gets 20mpg at best or a diesel that gets 30mpg? Thats a 50% increase in milage driven for an extra $1 to the gallon.

I dont beleive you will ever see diesel more than .80-.90 cents more a gallon than gas either so just because gas is cheaper by the gallon doesnt mean you are saving money in the long run.

All depends on the area, reformulated fuels, etc. I paid $0.93 more for D2 on monday, another station yesterday was $0.97 more.

And let's not forget we use to pay less for diesel versus regular unleaded gas...

I'm hoping for GM offering that gives us this. Just think 15 gallons of fuel and close to 1000 miles. How sweet would that be at $3.70 a gallon???

It could almost make me sell my motorcycle.

http://www.treehugger.com/files/2008/02/volkswagen_to_i.php

http://origin.www.treehugger.com/files/2008/04/vw-golf-turbo-diesel-hybrid-dead-tsi.php

yet again, car companies have no idea what they're doing... replacing a 70mpg VW golf diesel-hybrid with a 32mpg gas-hybrid.....

A diesel hybrid would rock. Just think what you could do with a tuner and exhaust. Maybe 75mpg. That would be like $5 a day to drive for me.

mine is about 17 city 21/22 hwy so it aint impossible

http://origin.www.treehugger.com/files/2008/04/vw-golf-turbo-diesel-hybrid-dead-tsi.php

yet again, car companies have no idea what they're doing... replacing a 70mpg VW golf diesel-hybrid with a 32mpg gas-hybrid.....

What really sucks because I was looking forward to buying one of those. I just bought an 04 TDI and am getting 47 mpg's while a few Prius owners I know are getting around 42 with all their hybrid glory.