The New 6.8L V8 Thread

[slemke]

19 hours ago, jpd80 said:

It’s not, the 3.5 EB will give better highway gas mileage.

Without cylinder deactivation, you’re looking around 16 mpg,

you’d be hard pressed to get 5 mpg improvement with cylinder deactivation.

Please explain how you arrived at your numbers.  As a point of reference, the GM 2.7 I4 turbo gets 23 mpg hwy, and the 5.3 v8 with dynamic cylinder deactivation also achieves 23 mpg….24 with the fuel economy package. 4wd numbers are the same for both at 22mpg.   The 5.3 is 2-3 mpg worse on the city cycle, though.  The 6.8L is not quite 2x the displacement of the 3.5 EB just like the GM 5.3 and 2.7 turbo.  Therefore, I would expect similar results for hwy mpg and probably 15% less in the city for the 6.8L vs the 3.5EB. Gear ratios, tires, and equipment levels will play a role in the final numbers.

 

I don’t see Ford dropping the 3.5L ecoboost in favor of a 6.8L due to city mpg, but the difference seems manageable to offer it on select models and not kill the cafe numbers.

[jpd80]

1 hour ago, slemke said:

Please explain how you arrived at your numbers.  As a point of reference, the GM 2.7 I4 turbo gets 23 mpg hwy, and the 5.3 v8 with dynamic cylinder deactivation also achieves 23 mpg….24 with the fuel economy package. 4wd numbers are the same for both at 22mpg.   The 5.3 is 2-3 mpg worse on the city cycle, though.  The 6.8L is not quite 2x the displacement of the 3.5 EB just like the GM 5.3 and 2.7 turbo.  Therefore, I would expect similar results for hwy mpg and probably 15% less in the city for the 6.8L vs the 3.5EB. Gear ratios, tires, and equipment levels will play a role in the final numbers.

 

I don’t see Ford dropping the 3.5L ecoboost in favor of a 6.8L due to city mpg, but the difference seems manageable to offer it on select models and not kill the cafe numbers.

The GM 6.2 with cylinder deactivation struggles to get 20 mpg in heavier pickups and SUVs, even with cylinder deactivation, do you think GM’s new 6.6 would get better or worse than 20 mpg?

 

In F250, the 7.3 gets around 15 mpg at 70 mpg  which is usually a rough indicator of what a CAFE truck highway mileage figure would be.

Edited August 24, 2021 by jpd80

[slemke]

2 hours ago, jpd80 said:

The GM 6.2 with cylinder deactivation struggles to get 20 mpg in heavier pickups and SUVs, even with cylinder deactivation, do you think GM’s new 6.6 would get better or worse than 20 mpg?

 

In F250, the 7.3 gets around 15 mpg at 70 mpg  which is usually a rough indicator of what a CAFE truck highway mileage figure would be.

If you want to move goal posts, sure a heavier truck with a larger frontal area will get worse mpg.  That and the 6.2 is only available in 4wd.  
 

put the 6.2 in a lighter truck and it will get better mpg.  The 6.6 doesn’t have cylinder deactivation.  6.6 might get better mpg in the heavier truck/suv as it wouldn’t have to work as hard.  Wasn’t that part of the reason Ford went with the larger 7.3L Godzilla over the 6.8L v10?  It wouldn’t work as hard under heavy loads and return better fuel efficiency for customers that towed and hauled. That was GMs philosophy for using the 350 in the large cars and performance cars instead of the 305 or 6 cylinder engines.  The 350 and later 6.2 got some impressive mpg for the power it produced in the corvette.

 

On the epa cycle, The 6.6 would likely fare worse than the 6.2 since the duty cycle is so light.  Who knows, though…the 4.3 v6 gets the same 20 mpg in 4wd as the 6.2l.

 

 CAFE uses the old 1979 standard, not the adjusted and updated numbers shown on the window sticker.  It is also a single combined mpg, not highway or city.  It will be higher than the 70 mph cruising mpg.  More like 55 or 60 mph.  Need to factor in that gas is really E10 here and not the E0 used in cafe testing, the really slow speeds and lethargic acceleration of the test.  The old epa estimates were really wild compared to what vehicles actually got and the window stickers and procedures subsequently revised to give a more realistic estimate. A 1983 F150 with a 300 I6 and 4 speed is epa listed at 23 mpg…that’s the cafe number.  I would think a modern 6.8 with cylinder deactivation and a 10 speed could equal that if not surpass it.  I read somewhere that the 6.2 ran the original test on only 4 cyl…might have been the corvette, though. Bottom line, a 6.8 will not help Ford’s CAFE numbers, but won’t be abysmal either.
 

 I wasn’t successful in finding Ford’s current cafe numbers for individual trucks to confirm.

[jpd80]

The point being that it’s much harder for a larger capacity V8 with cylinder deactivation to get close to the EB 35. I’ll give you the 5.3 V8 is a Mach in fuel economy but go to the 6.2 and it’s definitely less and then we talk 6.8 litres.. In a CAFE situation, those larger V8s will be restricted in amounts such that they are used in higher profit vehicles to limit sales.

Edited August 24, 2021 by jpd80

[ESP08]

15 hours ago, SoonerLS said:

Ford's customers are concerned with towing MPG, which means Ford is concerned with it regardless of CAFE. 

 

It's a distant secondary consideration for the typical half-ton buyer, IMO.  

Given the typical usage cycle of half-tons I'm sure the vast majority of buyers would prefer better unloaded MPG than better towing MPG. 

 

Towing MPG will be a much greater consideration for the 3/4 and 1 ton buyer.  

[LSchicago]

21 hours ago, silvrsvt said:

 

Ford is concerned with CAFE not towing MPGs that isn't counted.

Of course they are. Truck buyers are concerned with actual real life numbers. Two completely different mindsets.

[jpd80]

Lighter weight and improved efficiency are all beneficial to the customer and let’s not forget, you have to burn fuel to get power, F150 buyers like a truck with decent power and acceleration.

[69scode]

Is there any new information on this engine? The '22 models are starting to arrive and this was stated to be used in some of this model years vehicles. Stray Kat reported earlier that he heard the engine line might be running, so I would think something should be leaking out.

[Birdieman]

This motor was not included in either the MY2022 F-150 or Mustang order guides.  Maybe it will replace the 6.2 motor in the SuperDuty line;

[Stray Kat]

There are rumblings that the 6.8 may never happen now. Possible a victim of the push towards EV’s and the resultant need to dedicate the majority of resources in that direction. 

[twintornados]

19 minutes ago, Stray Kat said:

There are rumblings that the 6.8 may never happen now. Possible a victim of the push towards EV’s and the resultant need to dedicate the majority of resources in that direction. 

 

Since the 6.8L is based on the 7.3L Godzilla motor, the costs associated with development should be nominal. However, if the above is true...what a way for Ford V8's to go out...the 7.3L will be the last V8 ever developed by Ford.

[Power Kid]

Glad I didn't wait any longer and have a 7.3L coming...

 

 

[Stray Kat]

4 hours ago, twintornados said:

 

Since the 6.8L is based on the 7.3L Godzilla motor, the costs associated with development should be nominal. However, if the above is true...what a way for Ford V8's to go out...the 7.3L will be the last V8 ever developed by Ford.

That’s what I was thinking TT. If only a displacement change wouldn’t be much to develop it. 
 

I hope what I heard isn’t true but it wouldn’t surprise me. 
 

I am very on board with the EV thing but it would be very nice to have a cadre of classic big inch American V8’s for the swan song of the ICE era. 

[ESP08]

On 12/19/2021 at 6:40 AM, twintornados said:

 

Since the 6.8L is based on the 7.3L Godzilla motor, the costs associated with development should be nominal. However, if the above is true...what a way for Ford V8's to go out...the 7.3L will be the last V8 ever developed by Ford.

 

Pretty sad when GM's V8 swan song will likely be LT6 and it's derivatives.   

[Stray Kat]

1 hour ago, ESP08 said:

 

Pretty sad when GM's V8 swan song will likely be LT6 and it's derivatives.   

Chevrolet has built their franchise on simple easy to work with V8’s. While the LT6 looks like a dynamite package I don’t think it will have the mass appeal of say the LS series. 
 

Ford did the best job of bringing all that OHC multi valve tech to affordable American V8’s and they still play second fiddle at the grassroots level of performance. Not that they get outperformed but rather they are not chosen the majority of the time because of added complexity and raw girth. 
 

I think the 7.3 will have some staying power in that it will be used for the foreseeable future in commercial HD vehicles. Probably can and will be converted to run on natural gas and will be very appealing in the secondary grassroots performance market. 
 

I personally think Chevrolet would have been better served to build a super high performance Vette around an electric drivetrain. 
 

GM can’t breathe without owning all the magazine performance numbers. What are they going to do when the Tesla Roadster starts turning in consistent 8 second quarter mile passes?

[silvrsvt]

1 hour ago, Stray Kat said:

I personally think Chevrolet would have been better served to build a super high performance Vette around an electric drivetrain. 
 

GM can’t breathe without owning all the magazine performance numbers. What are they going to do when the Tesla Roadster starts turning in consistent 8 second quarter mile passes?

 

I remember seeing something recently about an E-Ray Corvette, not sure if its a hybrid or what...

 

 

[Power Kid]

Yah seen headline on wknd. Full e i think... 

[jpd80]

4 hours ago, silvrsvt said:

 

I remember seeing something recently about an E-Ray Corvette, not sure if its a hybrid or what...

 

 

What an unimaginative name……I think they were stumped after Volt and Bolt……nothing else rhymes with those…..

[Stray Kat]

https://fordauthority.com/2021/12/ford-7-3l-godzilla-v8-a-c-add-on-kit-now-available/

[7Mary3]

15 hours ago, Stray Kat said:

I personally think Chevrolet would have been better served to build a super high performance Vette around an electric drivetrain. 
 

 

Hold that thought....

[silvrsvt]

https://www.motorauthority.com/news/1133255_2023-chevrolet-corvette-e-ray-spy-shots-video

 

 

[ESP08]

On 12/21/2021 at 8:08 AM, Stray Kat said:

Chevrolet has built their franchise on simple easy to work with V8’s. While the LT6 looks like a dynamite package I don’t think it will have the mass appeal of say the LS series. 
 

Ford did the best job of bringing all that OHC multi valve tech to affordable American V8’s and they still play second fiddle at the grassroots level of performance. Not that they get outperformed but rather they are not chosen the majority of the time because of added complexity and raw girth. 
 

I think the 7.3 will have some staying power in that it will be used for the foreseeable future in commercial HD vehicles. Probably can and will be converted to run on natural gas and will be very appealing in the secondary grassroots performance market. 
 

I personally think Chevrolet would have been better served to build a super high performance Vette around an electric drivetrain. 
 

GM can’t breathe without owning all the magazine performance numbers. What are they going to do when the Tesla Roadster starts turning in consistent 8 second quarter mile passes?

 

The LT6 won't have the mass appeal or wide availability of the LS but I'm sure it will see success with later boosted variations though.     

Regardless, GM signs out of the ICE era on the highest note of their entire history.

Ford signs out of the ICE era with a whimper thanks to the 7.3 Godzilla...disappointing.  

 

If only we could have gotten a high performance variation of the Boss architecture.      SMH     

[JX1]

On 12/21/2021 at 1:06 PM, jpd80 said:

What an unimaginative name……I think they were stumped after Volt and Bolt……nothing else rhymes with those…..

Chevy Dolt???

 

Okay, more seriously...Jolt, Zolt (as in Zzzap)? Do I need to be doing GM's marketing for them?

[Stray Kat]

18 hours ago, ESP08 said:

 

The LT6 won't have the mass appeal or wide availability of the LS but I'm sure it will see success with later boosted variations though.     

Regardless, GM signs out of the ICE era on the highest note of their entire history.

Ford signs out of the ICE era with a whimper thanks to the 7.3 Godzilla...disappointing.  

 

If only we could have gotten a high performance variation of the Boss architecture.      SMH     

I respectfully disagree with you on this mainly because I think it’s far more valuable to create a versatile engine that has legs rather than a halo piece that will probably be a fond memory sooner rather than later. 
 

Ford fanatics have been craving a replacement for the 351 Windsor and 351 Cleveland for 20 years. Now we have a 445” canted valve V8 with no bottom end disappointments and tons of upside potential. 
 

I’m a motorsports enthusiast and I’d like to see Godzilla start showing up in Sand Cars and ski boats and maybe a “spec” engine series like the current Trans Am or NASCAR open wheel modified series. 
 

Great the new Chev LT6 is a fantastic engine. It will be annihilated by electric motors soon after it appears. I’d much rather have what Ford has finally given us as one last big inch ICE workhorse. 

[silvrsvt]

10 hours ago, Stray Kat said:

I’d much rather have what Ford has finally given us as one last big inch ICE workhorse. 

 

But its Metric ?