even though it's 2.1 liters smaller, it's only 55hp and 120lb-ft off of the LMMs. that's 15% more hp and 21% more torque for the LMM...but the 4.5L engine is 30% smaller. i think this engine is very respectible when it comes to power. here's the whole article...

http://www.leftlanenews.com/gm-releases-details-on-upcoming-duramax-45l-diesel.html

Did they say twin turbo? Or am i reading that wrong?

That is one awesome little Diesel. :D Mike

Did they say twin turbo? Or am i reading that wrong?

yeah, twin turbo is correct. i think that's half the reason for the great power numbers.

can't wait to drive one of those little buggers!!!! Should be fun

yeah, twin turbo is correct. i think that's half the reason for the great power numbers.

I can't wait to get my hands on one:D:driver:

This will definitely be my wifes next vehicle. Crew Cab 1500 4X4 with the 4.5 Duramax.

i once HEARD, idk if its true or not, but that this thing actually breaths backwards per say. So that the intake is where to exhaust used to be and exhaust where the intake usually is? is this true or did i hear wrong?

Hoping that it will have some good MPG numbers, like upper 20's to 30 MPG? Might be interested in one myself.

The new engine is only officially scheduled for use in the Chevy Silverado and GMC Sierra, but it will likely spread to GM's other full-size vehicles.

Hmm,,, they've already made a Suburban... hmmm.

Yes this engine breaths backward, intake on the sides, exhuast in the middle. THis minimizes heat loss to the turbo and shortens the exhuast piping allowing the engine to breath better. Intake isn't really affected becuase it was a long pipe before, and it's a long pipe now.

yeah it really seems like a much better idea in theory. does anyone know what trans they will be bolting to it since they parted ways with dmax, and allison???

The 6L90 (RPO "MYD"), the same "heavy duty" 6-speed transmission used in the current 6.0L gas HD pickup trucks, will also be used with the 4.5L diesel.
http://media.gm.com/us/powertrain/en/product_services/2008/Photo%20Library/Transmissions/2008%20Automatics/08_6L90_MYD_LoR.jpg
Though not as strong as the Allison, it provides increased torque capacity compared to the old 4-speed automatic. It has an extremely low first gear, like the 5-speed manual that is no longer offered. Its total gear range is wider than the Allison 6-speed.

Specs are at: http://media.gm.com/us/powertrain/en/product_services/2008/08truck.htm

2008 Hydra-Matic 6L90 Transmission ( MYD )
Type: six speed RWD / AWD, electronically controlled automatic overdrive transmission with torque converter clutch. Clutch-to-clutch architecture, with integral Electro / Hydraulic Controls Module
Maximum engine power: 452 bhp ( 337 kW ), Diesel: 300bhp ( 223kW )
Maximum engine torque: 531 lb-ft ( 720 Nm ), Diesel: 520 lb-ft ( 705 Nm )
Maximum gearbox torque: 885 lb-ft ( 1200 Nm )
Gear ratios:
First: 4.03
Second: 2.36
Third: 1.53
Fourth: 1.15
Fifth: 0.85
Sixth: 0.67
Reverse: -3.06


More info here:
http://media.gm.com/us/powertrain/en/product_services/2008/Spec%20Sheet/Transmissions/2008%20Automatics/08_6L90_MYD.xls
http://media.gm.com/us/powertrain/en/product_services/2008/Whats%20New/Transmissions/2008%20Auto%20Transmission/08_6L90_MYD.doc

Elvis, where do you find time to look up all of these references? Good job......

Hoping that it will have some good MPG numbers, like upper 20's to 30 MPG? Might be interested in one myself.

This is what I'm thinking. My 104 mile comute every day could use one of these plus the other places I go after work.

I wonder if they got their facts mixed up with the 4.5 dmax. Everything else published that Ive read says it will be a single turbo.

Elvis, where do you find time to look up all of these references? Good job......
I just "know" where to find the facts, quickly ;)

I wonder if they got their facts mixed up with the 4.5 dmax. Everything else published that Ive read says it will be a single turbo.

I saw the suburban with the 4.5L on display at last years SEMA show, I only saw one turbo hidden under the cover. I could have missed one however.

If I could only justify buying a suburban, that thing was sweet.

hmm...you guys could be right. that website has been known to muck things up from time to time. i can't find anywhere else where it says it is going to be a twin turbo.

here, but it's from a year ago...
http://www.gm.com/explore/fuel_economy/news/2007/adv_engines/diesel_061807.jsp

another little fun fact for ya...according to gm's website, their heavy duty pickup market share as increased 10-fold since the introduction of the first d-max. impressive...

and again...

http://www.autoblog.com/2008/05/05/gm-releases-details-on-upcoming-4-5l-duramax-turbo-diesel-v8/2

yea, that was a misprint on their part, one turbo only

and the intake and exhaust sides are reversed, reduces exhaust piping before the turbo = better spooling & efficiency

Just getting into the 4.5 info. So feel free to correct me on this stuff. I could swear that the exhaust runs in the valley (which I *think* was a Saab concept from a few years ago when GM wanted a high-spec V-6). I also was under the impression that this was sequential turbo (as opposed to "twin" which would indicate the same two turbos but one for each bank versus two in sequence).

To speculate I would imagine that if they go single turbo it'll be VGT. Okay who will run the exhaust stack straight out the hood first? Anyone? Anyone?

I jut don't get it! Why would GM produce an engine as powerful as the original Duramax that will get slightly better gas mileage than the LMM or LBZ and stick it into a 1500 platform? why not a 4 banger diesel like they have overseas that gets in the 30's or better? I get about 21 to 22 mpgs on the highway and another 3 to 5 miles in town or highway is not really going to get me to buy a 4.5! get me bout 150hps and 350 or so lbs and I buy one in 10 platform as any else is an overkill!

I jut don't get it! Why would GM produce an engine as powerful as the original Duramax that will get slightly better gas mileage than the LMM or LBZ and stick it into a 1500 platform? why not a 4 banger diesel like they have overseas that gets in the 30's or better? I get about 21 to 22 mpgs on the highway and another 3 to 5 miles in town or highway is not really going to get me to buy a 4.5! get me bout 150hps and 350 or so lbs and I buy one in 10 platform as any else is an overkill![/

If GM used your idea they would sell about 3 of them.

I jut don't get it! Why would GM produce an engine as powerful as the original Duramax that will get slightly better gas mileage than the LMM or LBZ and stick it into a 1500 platform? why not a 4 banger diesel like they have overseas that gets in the 30's or better? I get about 21 to 22 mpgs on the highway and another 3 to 5 miles in town or highway is not really going to get me to buy a 4.5! get me bout 150hps and 350 or so lbs and I buy one in 10 platform as any else is an overkill!

My guess is, the concept and design of this engine came about when GM was doing ok pushing large trucks and SUVs while gas was cheap. With that mentality they were thinking put a high hp/torque diesel in the slightly smaller trucks and SUVs that only have gas options because Americans want big vehicles and lots of power. If it gets slightly better mpg so much the better.

Now here we go again with the General unprepared for current market conditions and nothing ready to add to the lineup that offers what fuel conscious buyers are looking for. Sure, there's the $40,000 Volt in the wings, but $40,000 will buy a lot of gas even at $4.00/gallon. :shake:

I'm torn between being disappointed and offended that this is what the US auto industry thinks of me. I do need a 3/4 ton truck so they will be getting my business there. But this won't be my daily driver. That's a 2000 Mitsubishi which is still running good and getting 30+ mpg, but if I were looking to replace that it wouldn't be with anything coming from Detroit.

I would be willing to pony up the $ for the vault just so the middle east gets as little of my money as possible. Screw those guys, they are raking us over the coals right now, in thirty years I hope we don't need oil anymore or very little of it and they will be looking for a way to secure their future.

Most 2 car households would be well served to have 1 electric car...too bad you cant buy one. NEV's arent legal or even sold in most states. The only way the price of oil is going to change is if we change it by changing our demand.
I WANT MY ELECTRIC CAR PLEASE!!!

I jut don't get it! Why would GM produce an engine as powerful as the original Duramax that will get slightly better gas mileage than the LMM or LBZ and stick it into a 1500 platform? why not a 4 banger diesel like they have overseas that gets in the 30's or better? I get about 21 to 22 mpgs on the highway and another 3 to 5 miles in town or highway is not really going to get me to buy a 4.5! get me bout 150hps and 350 or so lbs and I buy one in 10 platform as any else is an overkill!


I agree I was reading about the Isuzu PUP diesel on wikipedia 33 city 44 highway yes it is a little too gutless but come on this was 1981. Thanks to emissions and now the fact that every car must weigh at least 4000lbs. we need a hybrid to get this mileage.

I would love to have a Colorado with the 3.0L Isuzu four cylinder diesel used in the DMAX but we cant build anything anymore that gets good mileage.

It is sad to see the cars that got the best mileage were produced in the 1980's

I here these commercial bragging how this vehicle gets an amazing 29 MPG first of that is best case scenario and second 29mpg for a car is crappy

and now the fact that every car must weigh at least 4000lbs.

I'm lost here?

It is sad to see the cars that got the best mileage were produced in the 1980's

Or 90's. A POS Geo metro gets ~46 real world mpg, while a new Prius gets real world ~35mpg. http://www.wired.com/cars/energy/news/2004/05/63413

For all the technology in the Prius, it weighs about 1100lbs more then a Geo. Weight trumps technology. :shootself

I'm lost here?

I think it's a reference to the structural reinforcements added to meet todays safety requirements. Heaven knows it's not due to thicker sheet metal used for the body. ;)

In the early 80s I had Plymouth Champ (Mitsibushi import) that got me 44 mpg. Today you need a hybrid for that. :confuzeld

I think it's a reference to the structural reinforcements added to meet todays safety requirements. Heaven knows it's not due to thicker sheet metal used for the body. ;)

In the early 80s I had Plymouth Champ (Mitsibushi import) that got me 44 mpg. Today you need a hybrid for that. :confuzeld

Exactly plus the 12 airbags

I hate to mention the "V" word....but Volkswagen has done pretty well with their TDI motors. My folks had a Jetta with a five speed and they'd get 54-55 mpg on the highway...of course they don't drive like I do :)....they're retired so not in a hurry to get places.