And now a reading from the book of Torque.

[91 s-10baja]

2008-May-08
And Now a Reading from Book of Torque: Our New 4.5 liter Turbodiesel


By: Gary Arvan
Chief Engineer, 4.5L







We’re launching a new, revolutionary (yeah, overused adjective, but in this case, it’s the real deal; stay with me here) 4.5l turbodiesel with a host of fairly innovative design features. If you like diesels, this motor is a monster. And it’s very, very clean.
First of all the, instead of putting the intake manifold inside the V (it’s a V8), we’ve reversed the airflow so that the exhaust manifold (and the turbo) are inside the V between the cylinder heads. This saves space under the hood, helping packaging, increasing efficiency, and helps on the emission front (the engine meets Tier 2, Bin 5 regulations). Of course, it will also have a state-of-the-art variable geometry turbo and high-pressure, direct-injection system.
We’re happy with our results, especially considering the aftertreatment: 310 hp and 520 lb./ft. of torque. Combine with a 25 percent fuel economy improvement over a similarly-powered gasoline engine and we’ve got a new benchmark for powerful efficiency.
http://blog.gmnext.com/?p=150

[bobojay]

Very, very anxious to see/drive one of these and how they do in the market.
Trouble is, right now here, diesel is 85 cents higher than unleaded.

[SCCA1995]

Originally Posted by bobojay

Very, very anxious to see/drive one of these and how they do in the market.
Trouble is, right now here, diesel is 85 cents higher than unleaded.

Yeah, but I'm guessing that you've driven one (riding in one isn't good enough). I love that big torque of a diesel. If this small V8 can get 25 mpg in a half-ton truck, watch them fly off of the lots.

[gerardo_zg]

An engineer saying "520 lb./ft. of torque".... a diesel engineer! No less!

[member12]

That's powerful. A similarly powered gas engine would be the 6.2L V8, which gets 12/18 mpg in the Sierra half ton.

At an average of 15mpg, a 25% improvement would mean an average of 20mpg, which means 17-18mpg city, 23-24mpg highway.

Not bad for a full sized truck with 520 lb-ft of torque.

If they mean 25% better than the 315hp 5.3L, then it's about 19mpg city/25mpg highway.


I get about 15mpg now (mostly city). If this new diesel would get about 18mpg under the same conditions, then I'd have to explore this.

That means that I'd spend (in fuel given the current prices) about:
$3400/year for the diesel
$3500/year for my current gas engine

If I can add the opportunity cost of the diesel engine (I like power) at about $500 + the $700 I would save over the course of 7 years then that means that I would be willing to pay $1200 for this diesel option over the 5.3L engine (which already cost $800 more than the base engine.
So, over the base gas 4.8L V8, the 4.5L diesel would have to cost no more than $2000. Over the 5.3L engine, it would have to cost $1200.

If it can get 20mpg average, then I'd be willing to pay a few hundred dollars more.

[FenwickHockey65]

24 MPG would be quite nice in a full size pickup.
And diesel's only 40 cents more here.
Now the question is, seeing the extra dollars spent on the big Duramax, is it worth it to go with the 4.5L?

[Sinner]

Originally Posted by member12

That's powerful. A similarly powered gas engine would be the 6.2L V8, which gets 12/18 mpg in the Sierra half ton.

At an average of 15mpg, a 25% improvement would mean an average of 20mpg, which means 17-18mpg city, 23-24mpg highway.

Not bad for a full sized truck with 520 lb-ft of torque.

If they mean 25% better than the 315hp 5.3L, then it's about 19mpg city/25mpg highway.


I get about 15mpg now (mostly city). If this new diesel would get about 18mpg under the same conditions, then I'd have to explore this.

That means that I'd spend (in fuel given the current prices) about:
$3400/year for the diesel
$3500/year for my current gas engine

If I can add the opportunity cost of the diesel engine (I like power) at about $500 + the $700 I would save over the course of 7 years then that means that I would be willing to pay $1200 for this diesel option over the 5.3L engine (which already cost $800 more than the base engine.
So, over the base gas 4.8L V8, the 4.5L diesel would have to cost no more than $2000. Over the 5.3L engine, it would have to cost $1200.

If it can get 20mpg average, then I'd be willing to pay a few hundred dollars more.

Don't forget the astronomical cost of diesel oil changes.

[THE_SMURF]

Originally Posted by SCCA1995

Yeah, but I'm guessing that you've driven one (riding in one isn't good enough). I love that big torque of a diesel. If this small V8 can get 25 mpg in a half-ton truck, watch them fly off of the lots.

We live in an area that has a lot of "Winter Texan" traffic during the cold months. This will be a big hit with a lot of these folks. A 1/2 ton with the ability to pull a 5th wheel that has 3-4 slides, should catch on with this crowd. Some actually drive or pull a smaller vehicle with them just so "momma" does not have to drive the 2500 to town for shopping. I believe me, WE WANT her to drive something smaller LOL.

[THE_SMURF]

Originally Posted by Sinner

Don't forget the astronomical cost of diesel oil changes.

The customer who buys a diesel usually needs a diesel, and/or already owns one and so any improvement in MPG will enhance the truck to them. They are already aware of the costs of ownership.

Whether the truck will be of any interest to the general public remains to be seen and I feel is directly proportional to cost of the fuel for them. With there being no end in sight to astronomical per gallon price of any fuel, do not see the owner of a heavy 1500 or light 2500 switching over to the small diesel unless they bought the big gas power plant by default, due to nothing else being available. The near $1.00 difference in per gallon in the fuels will cause some to shy away.
Of course, the MPG will make some look at the truck on that alone.

[GMCdriver]

Our gas went to 1.319/L(4.99/USgal) the other day while diesel is still down at 1.249/L(4.727/USgal). Pair that with the fact that Farmers can get Diesel for substantialy less then the rest of us common folk and this thing will have real fans as long as it is less then a $3500 upgrade from the 5.3.

[Butz]

Originally Posted by gerardo_zg

An engineer saying "520 lb./ft. of torque".... a diesel engineer! No less!

It gotta be a typo, I'm sure he is a busy man, he can't possibly proof read everything.

[member12]

Originally Posted by FenwickHockey65

24 MPG would be quite nice in a full size pickup.
And diesel's only 40 cents more here.
Now the question is, seeing the extra dollars spent on the big Duramax, is it worth it to go with the 4.5L?

The good thing here is that it doesn't require an Allison transmission....but if GM thinks they can charge $4000 for this engine option over the vortec max package, then they are mistaken. It won't sell in decent numbers for that price unless it gets 40 mpg. It might, however, sell pretty well in full sized vans, HD trucks, and HD suburbans, but it will replace the 6.0L engine. GM will need a smaller diesel to replace the 5.3L engine.

There there is the reliability issue.....GM has a mixed history with diesel engines. The Duramax and the 6.5L engine are okay, but I remember my parents 350 diesel. It may have gotten good mileage for the 20,000 miles or so that it ran, but it was a terribly unreliable engine.

Then there is the fact that Dodge is putting out a new Ram with a lighter duty cummins engine and Ford is building a less powerful 4.4L diesel for it's half tons that is expected to only cost around $1800 over the 5.4L engine.

There is a lot going against this new 4.5L engine. I hope for GM's sake that they can move them at a resonable price and that it scores great EPA ratings....but I have my doubts.

[plane]

<bleeped>
I wanted one of these so badly.
Man, all that torque.
And then I realized.
My local gas station is all out of urea.
And my 10-year survival supply of urea just ran out.
And I'm not comfortable dealing with black market urea dealers.

So, I'm on the fence at this point.

[cemaxc]

Originally Posted by member12

That's powerful. A similarly powered gas engine would be the 6.2L V8, which gets 12/18 mpg in the Sierra half ton.

At an average of 15mpg, a 25% improvement would mean an average of 20mpg, which means 17-18mpg city, 23-24mpg highway.

Not bad for a full sized truck with 520 lb-ft of torque.

If they mean 25% better than the 315hp 5.3L, then it's about 19mpg city/25mpg highway.


I get about 15mpg now (mostly city). If this new diesel would get about 18mpg under the same conditions, then I'd have to explore this.

That means that I'd spend (in fuel given the current prices) about:
$3400/year for the diesel
$3500/year for my current gas engine

If I can add the opportunity cost of the diesel engine (I like power) at about $500 + the $700 I would save over the course of 7 years then that means that I would be willing to pay $1200 for this diesel option over the 5.3L engine (which already cost $800 more than the base engine.
So, over the base gas 4.8L V8, the 4.5L diesel would have to cost no more than $2000. Over the 5.3L engine, it would have to cost $1200.

If it can get 20mpg average, then I'd be willing to pay a few hundred dollars more.

Thats pretty cost efficient. But just imagine if you lived where I do, just down the street from the Classic Chevrolet Alternative fuels station, the price difference would be even greater. BioDiesel there was 3.92 a gallon which is about $0.20 cheaper than regular Diesel here.

[MaxLegroom]

Next sick thought would be along the lines of just what that would do in a) the G8 and b) the Camaro...