Is their any advantage of going with a smaller displacement or size Diesel? 4cy or 6 Vs a V8? Do you get better fuel economy out of the smaller one? Why does Cummins always use I6? they seem to hang with the V8 Counter parts very well!

250HP and 400ft tq is more then enough for any 1/2 ton application IMO.

 

$4.59 a gallon is a pretty good reason.

Plus the Ram 3500 uses a 6 cyl. Diesel, its a big boy though, 6.7L

 

Yes, fewer cylinders means less friction and pumping losses. That's why variable displacement (AFM) works.

Cummins uses I6 because that's what their commercial engines are. Also, I6 has a balance advantage over an Vee. However, I6s can be hard to package.

 

I mentioned V-6 for their poor balancing, not really knocking I-6's. The 2.9L would be great for the 1500 trucks but silly GM probably doesn't have plans to do so. The big three all think we want to pay $4-8000 for diesel power.

 

Not exactly, our own government thinks we do however, specifically the EPA. US emission specification Tier 2 Bin 5 is six times more stringent than Euro V. Getting a diesel compliant with our regulations is costly.

 

I know its costly, but if they were to put a lighter duty diesel in the truck in the 200-250hp range the need for the Allison and 14bolt rear differential would not be needed and alot more people could afford the diesel engine. Plus the lower power and lighter components would increase mpg which is VERY important at $4-5 per gallon. If the 2.9L got only 2-3 more mpg you are talking about it costing you 50 cents less per gallon every time you fill up.

I bet the 4.5L will add $6000 to the price, the Allison will add another $1200. That starts making the 5.3L power pack for $1525 look alot more appealing. $5700 leftover will buy you an aweful lot of gasoline. I am just really dissapointed that the Big Three cant seem to offer a diesel for under $40k. More diesels could mean more biodiesel use and that kicks the middle east and russia right in the you know what. How many more years will it take to get a U.S. made diesel under 30K?

 

Who says the 4.5L would need the Allison? I'd seriously doubt they'd do that. The Allison doesn't fit well in the 1/2 tons as it is (without some floor pan mods, IIRC).

The CTS-V is going to offer the six speed auto with 550 hp / 550 lb-ft. I wouldn't be surprised at all to see the 6L80 or 6L90 behind the new diesel.

The AT is overbuilt for 1/2 ton duty.

 

Until you start modifications...then it would need the Allison