http://www.thestreet.com/_yahoo/newsanalysis/automakers/10422067.html?cm_ven=YAHOO&cm_cat=FREE&cm_ite=NA

I wonder if the 4.5 Dmax falls into this pullback ?

I have a hunch the 4.5 will get tossed due to the high price of diesel fuel and the downturn in the economy. What GM needs is a decent hybrid or hydrogen engine to boost sales. Of course we can't use hydrogen until there's an adequate distribution network for the fuel so it'll be a long time coming.

Meanwhile, diesels will become less popular as the price continues upward, will probably be around $7.00 a gallon this time next year.

The 4.5 will be here to help GM's CAFE number. It should "smoke" (pun intended) the 5.3L in the mileage department in a 1500 application.

The 4.5 will be here to help GM's CAFE number.

I'll need to see it on a showroom floor before I believe it.

I don't see it happening, diesel still 70 cents more than regular around here and no sign of changing....

Helping the CAFE numbers is meaningless if you can't sell the trucks and, at least for the present, full size trucks and SUV's are radioactive and sitting on lots unsold.

GM is in trouble. If they are looking at hocking assets to generate cash to survive they will be looking to cut everywhere

Helping the CAFE numbers is meaningless if you can't sell the trucks and, at least for the present, full size trucks and SUV's are radioactive and sitting on lots unsold.

Maybe this will help sell trucks. I for one would by a 1/2 ton if I could get around 25mpg.

I gotta believe the 4.5 will provide some pretty decent mileage in the 1500 application. Seems to me the 4.5 will not be on the chopping block. Maybe a 4.5/hybrid combo down the road...pretty good market for something like that right now.

I would imagine that they have already spent the lion's share of the money on this deal. That said, they are stupid.

Typical in US fashion. Build a smaller more fuel efficient engine, then pump up the HP and defeat the economy rating. My dad's old '82 6.2 with auto O/D used to average 25 mpg, and get about 30 mpg hwy. It was a 3/4 ton 2wd, and it only made about 130 hp, but you know, it still did everything we needed it to do in construction. Keep the hp low, let it sip fuel, get the CAFE numbers you need, then let the tuners pump them back up if need be. After all, GM can increase the hp of their engines, but when they do it, fuel economy suffers, the tuner companies do it, and economy gets better, you figure it out.

They just did a redesign. Let them go back to a 12 - 15 years between new models. I like it when all my trucks match. Why not use the 4 cyl that is in the W 3500 and W 4500.

The hybrid Tahoe/Yukon seem like proof of concept vehicles and real-world test-beds brought to market in order to iron out any bugs in the basic hybrid system while using a proven control engine (the LS-series).

It also effectively tests the market demand for full-size hybrids while the technologies mature.

Maybe the real intended engine is the not ready for primetime 4.5L diesel.

We could be looking at a hybrid-diesel that gets 25-30% better mileage than the smaller-displacement diesel alone.

A B100-capable full-size pick-up or SUV which gets 33-MPG Hwy & City would be quite the corporate savior.

-P.

it'll all boil down to real world mpg numbers. People still need their pickups. Sure the casual owner is no longer going to buy the trucks, but the campers, haulers, contractors etc still need these trucks. If they can make the truck a decent workhorse and deliver decent fuel economy these trucks will fly off the shelves so to speak.

Manufacturers need to make more pickup and engine options supporting weekend/medium and everyday/heavy hauler/towers. Making a 4.5L diesel as capable as the 6.6L is out of step with today's fuel costs. Hope we don't go back to the days of overloaded a$$ dragging station wagons hauling trailers, etc.

Manufacturers need to make more pickup and engine options supporting weekend/medium and everyday/heavy hauler/towers. Making a 4.5L diesel as capable as the 6.6L is out of step with today's fuel costs. Hope we don't go back to the days of overloaded a$$ dragging station wagons hauling trailers, etc.

Memoriesss.....

Typical in US fashion. Build a smaller more fuel efficient engine, then pump up the HP and defeat the economy rating. My dad's old '82 6.2 with auto O/D used to average 25 mpg, and get about 30 mpg hwy. It was a 3/4 ton 2wd, and it only made about 130 hp, but you know, it still did everything we needed it to do in construction. Keep the hp low, let it sip fuel, get the CAFE numbers you need, then let the tuners pump them back up if need be. After all, GM can increase the hp of their engines, but when they do it, fuel economy suffers, the tuner companies do it, and economy gets better, you figure it out.
Simple. It really doesn't have much to do with the HP rating, it's all about injection timing. The newer trucks have much tougher NOx specs to meet and so injection timing is retarded from the factory to meet those requirements. The tuners increase injection timing and that's where the increased MPG comes from. That's also the reason why the higher tuner settings increase mpg all the more, becuase the higher settings increase injection timing more then the lower settings. The tuner companies do not have to have their tunes emission certified. Most of the after market tunes would probably not pass the NOx requirement, but HC's are probably better as long as the tune is not too extreme.

Trucks have also gotten a lot heavier in the last 10-15 years, so that doesn't help mpg either.

Typical in US fashion. Build a smaller more fuel efficient engine, then pump up the HP and defeat the economy rating. My dad's old '82 6.2 with auto O/D used to average 25 mpg, and get about 30 mpg hwy. It was a 3/4 ton 2wd, and it only made about 130 hp, but you know, it still did everything we needed it to do in construction. Keep the hp low, let it sip fuel, get the CAFE numbers you need, then let the tuners pump them back up if need be. After all, GM can increase the hp of their engines, but when they do it, fuel economy suffers, the tuner companies do it, and economy gets better, you figure it out.
I'll agree with that...the 6.2/6.5 had it's share of problems, don't get me wrong, but I know several folks around here that swore by them, and still do...one farmer I know bought a 2 door Blazer diesel every year or so they made them, and was in a rage when they quit making them.

My wife drives an 8.1L Suburban, and I've always dreamed of dropping a Dmax/Ally in one...but I'm wondering if the detuned Dmax/4L80e combo wouldn't be the cat's pajamas, considering we have our trucks if we need to tow heavy? She absolutely loves driving her Sub, and I haven't been able to convince her of any other rig on the market...!

The 4.5L in a 1/2 ton or even light duty 3/4 ton chassis sounds like a smart option to me...