It would be interesting to see how the SIDI 3.6L would do in a Tahoe.

 

If this is the case, it makes the Acadia Denali's lack of an upgraded engine even more disappointing.

 

Not really. A configuration like that in a Tahoe would be woefully short on torque.

 

BOF is stronger than unibody, you'll never get the same capabilities. Not that it matters to most buyers out there. By the time you're done reinforcing unibody, you might as well go BOF.

A proper truck is BOF. Just like a proper sports car is RWD-based, not FWD.

 

Moreso than, say, a 4-cylinder automatic Camry (one of the best-selling cars in the world)?

Camry with 2.5L 4-cylinder and the auto: 167 lb-ft, 3307 lbs
3307 / 167 = 19.8 pounds per foot-pound.

Imaginary 2WD Tahoe w/ 3.6L DI: 273 lb-ft, 5265 lbs (possibly less; this is the spec weight with the 5.3L)
5265 / 273 = 19.28 pounds per foot-pound.

Regular 5.3L Tahoe: 335 lb-ft, 5265 lbs
5265/ 335 = 15.716 pounds per foot-pound.

Don't like torque-to-weight as a measure? The imaginary 3.6L Tahoe fares even better in this comparison if you use power-to-weight instead.

What you've created here is a truck that accelerates ~2% faster than a 4-cylinder Camry. It'd get kickass gas mileage (for a truck). I don't think it could do much in the way of towing/hauling, but I could be wrong -- towing and hauling is more about transmission, suspension, and brakes than it is about the engine.

I say build it, with the Z66 street suspension package or a slight variation thereof, and market it as Tahoe XFE (the high-efficiency trim level).

 

I would say that the expectations for a 4-cylinder Camry would differ quite a bit to the expectations of a full-size truck/SUV.

GM had been offering the old 4.3 V6 in its full size trucks, and although it was admittedly down on power compared to the new 3.6 it was also by far the least popular motor in the entire line. As we have learned over the years here, it costs a lot of money to certify a new engine in a vehicle line - they aren't "plug & play" - so GM would have to have a strong case that the 3.6 option would be profitable.

I'm not sold on the whole "kickass" assumption of fuel economy with a 6 in the GMT-900 either. I am assuming the torque "sweet-spot" is higher up the band on the 3.6 compared to the 5.3 V8, so most of the fuel savings could be eaten up by either the transmission calibrations or the driver's heavier foot (or both) to get that all that mass moving.

 

6 speed transmission can make up for some of that. It wouldn't be the engine of choice for someone looking to tow, but how many SUV owners really do that.

3.6L = 273tq, ten years ago the 4.8L in the Tahoe made 290tq and only had a 4 speed transmission.

4cyl. Equinox might be a good comparison of power to weight. 75% of buyers are going for the 4cy.

 

Agreed, but all it takes is a well planned marketing campaign to change that.

Good points.

The torque peak on the 3.6L DI is 1200rpm higher than on the 5.3 (5200 vs 4000), but from the couple of 3.6L DI dyno graphs I've been able to find online, it looks like torque is above 90% of peak from ~2200 to 6000 rpm. It might be better yet -- it's hard to find a dyno pull that started lower than 2200.

I'm sure that the 5.3's torque comes in even lower, but I think 2200rpm is a fine cruising RPM.

 

I had always heard that Lambda was designed for the UV8. That would mean that an Escalade Lambda might not be V8 equipped now, given the tossing of the UV8 a couple years ago.

My question is this: will the BOF SUVs only include Escalade, Yukon XL (probably named simply Yukon) and Suburban? Or will they include regular Yukon and Tahoe siblings as well.

Seems with sales falling off so much and Traverse and Acadia/Enclave being the 'spiritual' successors to Tahoe and Yukon that we might see the BOF fleet parred down a bit. I mean, I know that technically Lambda replaced the GMT360s. But lets face it, the GMT360s, especially the extended 370 versions were in the same market as the short GMT800s/900s.

 

I can't see why they would separate the Tahoe and Suburban, they are basically the same vehicle just one is stretched. Doesn't really cost anymore to have both. Ford just added an Expedition XL a year or so ago.

 

My thoughts were that Tahoe and Yukon might be phased out based on pending CAFE.

 

I see WAY, WAY too many Tahoe and Yukon the road here for GM to even put ANY thought into canceling them.

 

Terrain, Equinox, Orlando (or what ever it is called) and the GMC Granite will all give GM's truck CAFE rating a huge boost. As said in another thread 75% of Equinoxs sold are the new 4cyl. models.

The 2.9L diesel V6 with 400tq would make a great Tahoe engine and if that can't be done I could see a lot of people opting for the direct injection 3.6L V6 in their Tahoes that they don't go off road or tow with.

 

How about a 4-cylinder BOF truck? With 4-speed auto? You'll find that locomotive setup in your next-gen 4Runner. Granted, it's not Tahoe's size.

4295 lbs. powered by 178 ft-lbs.
That's 24 lbs per ft-lb.

Another thing that I'm wondering about is how much will the fuel economy on the Tahoe improve with a six-cylinder engine? I don't think it will be beyond 1 mpg or 2 at best.

 

I'd like to see them resurrect the light duty diesel project that got cancelled with Chapter 11. I think it was 4.5L, maybe? (Man I'm rusty) Supposedly a revolutionary powerplant.

I'd love to see the Yukon and Tahoe stay, but I know that phase out was being contemplated when the new CAFE legislation was signed. And it is interesting that the article doesn't specify which (or multiple) BOF offerings at each channel. Just some thoughts...