In the 4.8? I guess so, but they haven't have they?

Seems like one of the issues is the 5.3 already has a tough time staying in 4cyl mode during even the lightest of acceleration or at highway speeds anything about 60 or so (too much wind resistance). So the 4.8 might have an even harder time?

The 6.2 doesn't currently use AFM to my knowledge... wonder if that's in the plans anytime soon? With that much power and 6 gears to choose from I bet it could stay on 4 cylinders a lot more often than the 5.3 and 4-speed combo has been able to.

 

Yes, I would assume that's one of the reasons GM uses the 6.2 in the new hybrid trucks.
Or, they could take a cue from Honda (V6 that switches to V4 mode) and instead of running V8/V4 run V8/V6.

 

I thought they used the 6.0 in the hybrid trucks?

edit: you probably already knew this but the Honda V6 will run in both 3-cyl and 4-cyl mode.

 

The 6.2 is uses AFM and VVT AFAIK. The 4.8 is around to upsell people the 5.3 V8. If they didn't have the 4.8 then there would be no reason to pay more for the 5.3, this is just my opinion but it is a pretty good one isn't it?

 

Right on both counts...

 

I don't want one personally (I like heavy-duty 4x4s), but I think it'd be good for the line-up. However, such a vehicle may be more difficult to do in the new CAFE environment.

Well, I don't think that the 5.3L will get appreciably lower economy ratings, and will likely constitute a small percentage of take rate. But, in the future, I think that sort of truck is coming to an end as the CAFE rules continue to evolve.

Indeed, trucks could get larger to get around the CAFE regs, but I don't think the market will continue to support ****-poor fuel economy. The V10 Excursion made some sense in the day of $0.95 gas, but it'd be a hard sell nowadays.

 

I just went to Chevrolet.com and looked at the Tahoe's powertrain spec sheets. They very actively advertise the active fuel management on the 5.3 and 6.0 but I can't find a single mention of it in in the description for the 6.2 which makes me think it doesn't use AFM.

 

I don't think the 6.2L uses AFM.

Not sure why that is, as it seems quite likely to have the power/torque to spend more time in 4 cylinder mode, but...