C/K Man

Looks like the 6.6L gas is going in the 2020 4500 and 5500 LCF's later this year, and the Express/Savanna in 2021. A version of the 6.6L gas is rumored for the 2021 Silverado 4500/5500/6500.

I am hoping GM or PSI will develop a CNG/LNG conversion for the 6.6L.

The 7.3L is not even that much larger.

Looks to me like it's based on the Chevy LS more than anything! Don't see any Windsor in it, but the Ford 7.3L is built in the Windsor engine plant. Maybe that confused someone.

It looks like the L8T 6.6L will soon be available in the 3500/4500 LCF medium duty trucks. No word yet on the Silverado 4500/5500/6500 yet.

Regarding the TFL testing, I have some questions. First off, back in December TFL took delivery of a red 7.3L F-250 XLT crew cab with the 5th. wheel hitch package. Similarly equipped to the 2020 6.6L gas Silverado HD they tested on the Ike. TFL in fact said they were intending to test and compare that particular truck to the Silverado HD they tested. TFL didn't state what gears the Red F-250 was equipped with. Yet, when TFL finally did test a Super Duty with the 7.3L on the Ike, all of a sudden they had a blue 7.3L F-250 with the 4.30:1 rear axle. Hmmmm. For the record, a 2020 Silverado 6.6L gas 4X4 crew cab short box with the standard 3.73:1 rear axle can tow 16,600#'s on a 5th. wheel. A 2020 F-250 7.3L gas 4X4 crew cab short box with the standard 3.55:1 (3.73:1 only available with the 6.2L in the F-250) rear axle can only tow 14,700#'s on a 5th. wheel. An F-250 7.3L with the optional 4:30 rear axle is rated for 16,900#'s. My guess is TFL used the blue F-250 probably because the red one had a 3.55:1 rear axle! That having been said, a more accurate comparison between the 6.6L and 7.3L would have been to use a 6.6L with a 3.73 rear axle against a 7.3L with a 3.55:1 rear axle, both trucks towing 14,000#'s to keep the towing weight under the F-250's maximum.

Sort of explains the 6 speed transmission and 3.73:1 rear gears.

Body control module? Was the truck in a flood?

Yes, while the 6.6L is technically new, there really isn't anything in it that has not been in one LS/LT or another. I like the look of the new GMC Sierra HD's, the Silverado HD not so much........

Looking at the videos, there is a lot to like about the 7.3L. Crank and main caps look good, oil pump/windage tray is clever, big valves and sturdy valve train. Large cooling passages. Head bolts go deep in the block, longer than I originally thought. On the other hand, bore spacing is very tight, head gasket sealing surface is minimal, large front cover has 3 water passages (potential leak paths into crankcase), VVT components appear to be inaccessible unless timing cover removed. Typical Ford, for every good feature you find one questionable one. At the end of the day you have an engine that compared to the new GM 6.6L gas is a little over 10% larger, produces a little less than 10% more horsepower, and makes essentially the same torque with similar curves.

Particularly for you LS fans, take a good look at these Ford 7.3L videos:

https://www.worktruckonline.com/145796/dot-mandates-may-apply-when-using-trailers The DOT regulations come into play when your GCWR (truck + trailer) are over 10,000 lbs., so technically even a 1500 could fall under DOT if it was towing a large enough trailer. These days often there is no difference in emission controls between California and Federal vehicles, everything is built to the California standard. The difference is in the testing and certification.

I agree, most of the 7.3L's advantage is attributable to the 10 speed transmission and 4:30 gears. Which leads to the question how would the L8T be with a 10 speed transmission and similar gears.

You would need to compare the RBM of the frames to get a definitive answer. We have a few 2019 Super Duty's in our fleet now, and looking at the frame it there seems to be quite a variance in material thickness and dimension front to rear. Very understandable, I am sure Ford does not want to waste money on material in less critical areas. I think the new Super Duty frame is a big improvement over the old one. Is it substantially better that the GM HD frame? Couldn't tell you at this point.

My company finally got a few. 6500 2 yard dumps. Drivers and mechanics like them so far.