I got 18-19mpg over the winter, but ever since I broke 10,000mi about 2 months ago I've been getting 20-21mpg with 21.4mpg being my best. I have the 3.73 gears and my truck feels about as strong as my 3800 V6 Grand Prix did. 4.8L is the perfect mix of fuel economy and power for those who would want more out of there Colorado.

The I5 with a boost up to 240HP would be fine in 2wd Silverados with the W/T package. Basically I'd only use it were the V6 was used in the past.

It will be interesting to see if the 400HP 6.0L is offered in the 1500 Silverados, I doubt it, unless other 1500's get 400HP. It will probably be used just in the Escalade and Denali and many the regular Silverado SS (with the S/C SS getting a superchared LS2)

 

Is the 6.0 going to be available in the standard GM trucks, or only the suburban/luxury/performance/three-quarter ton setups?

Even so, the 5.3 will be very competetive with everyone else's offerings.

So it is confirmed that these motors even though they have retained their previous displacements, are based on the LS2?

The 6.0L makes ~ the same power in the trucks as it does the Vette. Is this just by chance or are they nearly identical motors?

 

what about the transmissions of the GMT900? They are going to be the 6 speed auto's right? Anyone know of the stats of them?

 

Yes they will get the 6 speed autos.

I Assume the rumors of the V10 being canceled are true since the 8.1L is still around.

 

How sweet would it be to see the 8.1 go Aluminum and get DOD?

I know a lot of hot rodders would drool over that setup, especially with the 6 speed auto!

 

That would be a lot of investment considering how limited production the engine really is, and not being based off either Gen III or Gen IV (Hell..Gen I or II even...its Mark IV), that would be a heavy investment for an engine that I have never seen in a Chevy truck.

 

The 6 liter in the trucks won't be an "LS2" per se. Even though peak horsepower and torque are about the same, I'm guessing the torque curves will be different. The LS2 should spin more RPMs too. One is for use in a sports car and the other for a heavy duty truck.

 

Same block, different heads and cams.

 

My father-in-law has the Vortec 8100 with the Allison 5 speed auto in his 2005 GMC Sierra 2500HD...

He has a 24' trailer (for cars)... we hauled the 67 SS396 Chevelle back to it's owner this weekend... the first time we've trailered with the new truck. It is a NIGHT AND DAY difference between that 8100/Allison and his 2003 Silverado that had a 6.0/5.7 (Whatever the medium V8 was in 03)

In short, the 8100 is very much worth it if you are going to actually use it....

 

Betcha that has a lot to do with the Allison.

Methinks the Allison needs to be marketed more heavily. Really throw it out there like DCX has with the Hemi.

Besides, you could show pictures of some of Allison's earlier successes... like the P-38 Lightning with twin V-1710's gunning down a Zero or three...

After that, get Pratt and Whitney to build an engine for ya and you've closed the whole loop. Then you can show Hellcats and Corsairs and Thunderbolts...

Preferably with Iron Maiden playing in the background...

But seriously, I think the Allison should be played up a bit more than it is. It's a hell of a transmission.

 

It would without a doubt not hit anything close to the impact and word of mouth hoopla that the Hemi has and still is. The average consumer does NOT... I repeat, NOT, get excited about a transmission. Most people out there don't even really know completely what a transmission is exactly or how many gears they have... much less its manufacturer, predicted durability, etc, etc.

Preaching Allison transmissions to the truck market may be a good short marketing campaign among many others... but I don't think it's going to make any giant impact on its own, at all.

 

I think that you would be right about sedans and vehicles for the general public but the people who buy these workhorses alreday know about the Allison and they love it. It would only help to increase the knowlege base of the buyers and give your truck something the competition doesn't have.

 

I think that for the niche market that would be interested in workhorses with Allison transmissions, that would be a great marketing tool. But again, we're talking about niche marketing. The Hemi was about as far from niche marketing as you can get, because it has spread among performance car enthusiasts, family dads, soccer moms, and truck guys alike.

 

Another interesting tidbit about the 8100/Allison vs the 5.7( or 6.0?)/4 speed is that we actually got one MPG BETTER on our trip towing the Chevelle back to the owner than we did with the old truck when we picked it up....

I'm going to assume that the extra gear made a big difference there, being that the engine is much bigger, yet it still got better economy towing.

 

Well when you unhooked the trailer the 8.1 probably still got the same mileage.