2023 6.6 Gas Real World Towing Observations

nick112288 · January 29, 2023

20 hours ago, Pryme said:

The 6.6 gas already dynos right with the 7.3. So the 6.8 they are offering with the base truck, which is a dumb idea and only good for ford to boost higher trim sales, is not even close. I also read it doesn’t even have a forged crank.

I'm not saying you're wrong, but where are you seeing that?

Just a quick Google search the 6.6 dyno sheet I saw put the 6.6 at the same as the discontinued 6.2, and about 20hp/20tq behind the 7.3

6.6 - 330/360

6.2 - 330/360

7.3 - 350/380

It was hard finding just a stock dyno. Everything showing up at the top is at least a tune, but quite a few quoting blower runs as well.

Jettech1 · January 29, 2023

12 minutes ago, nick112288 said:

I'm not saying you're wrong, but where are you seeing that?

Just a quick Google search the 6.6 dyno sheet I saw put the 6.6 at the same as the discontinued 6.2, and about 20hp/20tq behind the 7.3

6.6 - 330/360

6.2 - 330/360

7.3 - 350/380

It was hard finding just a stock dyno. Everything showing up at the top is at least a tune, but quite a few quoting blower runs as well.

Here we go....seems like TFL already did a dyno test....and it's impressive...

nick112288 · January 29, 2023

46 minutes ago, Jettech1 said:

Here we go....seems like TFL already did a dyno test....and it's impressive...

Here is the 7.3/6.2 dyno sheet I found.

https://www.f150forum.com/f17/5-star-tuning-stock-2020-f250-7-3-dyno-s-465117/

Jettech1 · January 29, 2023

21 minutes ago, nick112288 said:

Here is the 7.3/6.2 dyno sheet I found.

https://www.f150forum.com/f17/5-star-tuning-stock-2020-f250-7-3-dyno-s-465117/

Dyno results are only valid when tested 1:1 final ratio. The 10R140 trans used behind the 7.3L engine is impressive to say the least. But.....for a true dyno result that combo will need to be run in 7th gear. All other gears are basically useless because they are not 1:1 final drive ratio. With the 6L90E you can get close to 1:1 in 4th gear. 5th and 6th are overdrives.

Edited January 29, 2023 by Jettech1

nick112288 · January 30, 2023

44 minutes ago, Jettech1 said:

Dyno results are only valid when tested 1:1 final ratio. The 10R140 trans used behind the 7.3L engine is impressive to say the least. But.....for a true dyno result that combo will need to be run in 7th gear. All other gears are basically useless because they are not 1:1 final drive ratio. With the 6L90E you can get close to 1:1 in 4th gear. 5th and 6th are overdrives.

I knew it needed to be in 1:1 to really give good results, I didn't take the time to check the gears in the 10r140. I figured since they dynod in 2 different gears one of them was going to be 1:1. Now I'll have to try and find a dyno that's in 7th to see how it compares.

Jettech1 · January 30, 2023

3 minutes ago, nick112288 said:

I knew it needed to be in 1:1 to really give good results, I didn't take the time to check the gears in the 10r140. I figured since they dynod in 2 different gears one of them was going to be 1:1. Now I'll have to try and find a dyno that's in 7th to see how it compares.

That gives me some great inspiration. I used to have all my vehicles dynoed years ago. Perhaps its time I get back into that and have the beast dynoed...hmmm.....I like this idea...

Pryme · January 30, 2023

3 hours ago, nick112288 said:

I'm not saying you're wrong, but where are you seeing that?

Just a quick Google search the 6.6 dyno sheet I saw put the 6.6 at the same as the discontinued 6.2, and about 20hp/20tq behind the 7.3

6.6 - 330/360

6.2 - 330/360

7.3 - 350/380

It was hard finding just a stock dyno. Everything showing up at the top is at least a tune, but quite a few quoting blower runs as well.

I also found the one Jett posted and this one for the 7.3

Each truck from both manufacturers will have variance but in these two examples they are nearly equal

Stand By · February 24, 2023

What torque converter failures behind the 6.6? Haven't seen anything posted.

Doodle · March 15, 2023

Had a chance to pull my flatbed trailer today to get a feel for how this gas does with some pretty heavy weight. Trailer is 5450 lbs empty, load was about 12,500. So nearing 18,000 lbs total combined trailer weight. Pickup weighs in about 7200 lbs so basically sitting at 25K GCVW. It was really windy today. Had a bad cross wind then had to drive directly into the wind. I was pretty happy with the performance. I didn't drive much above 60 mph because it was so windy, but it would have done it no problem on a calm day. Just kept the trans locked out of 6th and it pretty much held 5th gear once up to speed. Only towed this weight about 30 miles or so. To be upfront I would never pull this weight if I was pulling in a hilly area. I live where it's flat so I get by with it. But having said that I had no issues handling the weight at all. If this new 10 speed is even better I doubt I'll ever go back to a diesel again unless I tow regularly or move to an area where there is a lot more hills.

Jettech1 · March 15, 2023

5 minutes ago, Doodle said:

Had a chance to pull my flatbed trailer today to get a feel for how this gas does with some pretty heavy weight. Trailer is 5450 lbs empty, load was about 12,500. So nearing 18,000 lbs total combined trailer weight. Pickup weighs in about 7200 lbs so basically sitting at 25K GCVW. It was really windy today. Had a bad cross wind then had to drive directly into the wind. I was pretty happy with the performance. I didn't drive much above 60 mph because it was so windy, but it would have done it no problem on a calm day. Just kept the trans locked out of 6th and it pretty much held 5th gear once up to speed. Only towed this weight about 30 miles or so. To be upfront I would never pull this weight if I was pulling in a hilly area. I live where it's flat so I get by with it. But having said that I had no issues handling the weight at all. If this new 10 speed is even better I doubt I'll ever go back to a diesel again unless I tow regularly or move to an area where there is a lot more hills.

That's a lot of weight my friend. Wow...the gasser is amazing for sure.

Doodle · March 15, 2023

10 hours ago, Jettech1 said:

That's a lot of weight my friend. Wow...the gasser is amazing for sure.

Yeah like I said probably wouldn’t do this in a hilly area but get by with it out here. Honestly braking and stability were no issue. The 23 with the 6 speed is rated for 24K GCVWR. The 2024 is supposed to be up to 26K GCVWR. So technically I wasn’t too far off what the pickup was rated for. Not saying should do it all the time but it can be done. The 23 feels better towing than my 2015 but the LML will tow the weight better.

Pryme · March 15, 2023

6 hours ago, Doodle said:

Yeah like I said probably wouldn’t do this in a hilly area but get by with it out here. Honestly braking and stability were no issue. The 23 with the 6 speed is rated for 24K GCVWR. The 2024 is supposed to be up to 26K GCVWR. So technically I wasn’t too far off what the pickup was rated for. Not saying should do it all the time but it can be done. The 23 feels better towing than my 2015 but the LML will tow the weight better.

Wow that’s a load! So is it revving up over 5k to get up to speed with that load? What about braking? Does it downshift a ton to help slow that kind of load? Doesn’t look squatted at all

Doodle · March 15, 2023

2 minutes ago, Pryme said:

Wow that’s a load! So is it revving up over 5k to get up to speed with that load? What about braking? Does it downshift a ton to help slow that kind of load? Doesn’t look squatted at all

Actually the 6 speed is geared low enough from 1-3 it gets the load moving pretty good without a ton of revving. Where the flat spot is is from 3-4th. Think the 10 speed will help that. Sure it will rap out to 5K if I was flooring it all the time but if I just take my time it doesn’t scream too much. Braking is fine with the load but not having an exhaust brake like my LML has does suck. It will downshift some to help slow the load in tow/haul but it’s nothing like the exhaust brake on the diesel. I had a pretty good squat with it compared to my 2015 with air bags, but I will tell you it handles the load better than the 2015 with air bags in my opinion. Frame is pretty stout on the 2020+. It sits up a lot higher than my 2015. I was only 65 yesterday but trans temp never went above 165. I’ve never seen it get higher than that but I haven’t pulled in 100 degree heat yet either.

I will say this thing tows way better than the old 6.0 4-speed I had but that was a 2005 so really can’t compare that at all to the newer 6.0L with the 6 speed. I’ve never actually driven one of those.

I kept hoping maybe GM would up the HP/TQ on the L8T with the refresh but so far they haven’t and probably never will. I think something like 450HP/500TQ in a gas would just about meet most everyone’s needs for towing with a gas. That would help in the elevation areas. I know some will think providing a better gas engine will hurt diesel sales, quite honestly wouldn’t GM be better off anyway then you don’t have all the crazy expensive emissions warranty claims? Just my $0.02.

Pryme · March 15, 2023

10 minutes ago, Doodle said:

Actually the 6 speed is geared low enough from 1-3 it gets the load moving pretty good without a ton of revving. Where the flat spot is is from 3-4th. Think the 10 speed will help that. Sure it will rap out to 5K if I was flooring it all the time but if I just take my time it doesn’t scream too much. Braking is fine with the load but not having an exhaust brake like my LML has does suck. It will downshift some to help slow the load in tow/haul but it’s nothing like the exhaust brake on the diesel. I had a pretty good squat with it compared to my 2015 with air bags, but I will tell you it handles the load better than the 2015 with air bags in my opinion. Frame is pretty stout on the 2020+. It sits up a lot higher than my 2015. I was only 65 yesterday but trans temp never went above 165. I’ve never seen it get higher than that but I haven’t pulled in 100 degree heat yet either.

I will say this thing tows way better than the old 6.0 4-speed I had but that was a 2005 so really can’t compare that at all to the newer 6.0L with the 6 speed. I’ve never actually driven one of those.

I kept hoping maybe GM would up the HP/TQ on the L8T with the refresh but so far they haven’t and probably never will. I think something like 450HP/500TQ in a gas would just about meet most everyone’s needs for towing with a gas. That would help in the elevation areas. I know some will think providing a better gas engine will hurt diesel sales, quite honestly wouldn’t GM be better off anyway then you don’t have all the crazy expensive emissions warranty claims? Just my $0.02.

They don’t want to lose too many diesel truck sales. That’s why they dangle the carrot but never let the gas get too crazy.

Edited March 15, 2023 by Pryme

the wanderer · March 17, 2023

On 3/15/2023 at 6:00 PM, Pryme said:

They don’t want to lose too many diesel truck sales. That’s why they dangle the carrot but never let the gas get too crazy.

Possibly. But Ford's 7.3 is quite a bit stronger yet than the 6.6, and all these 2500 gassers seem to be in the same rough hp/displacement so maybe it's less a carrot issue and more a simple engineering issue; it's just harder and harder to make more power with a N/A gas engine.

If getting a stronger gas engine means less reliability than I don't think that tradeoff is worth it. Gas should always be the cheap/reliable option.

I've always felt that the first brand which comes with a mid range diesel will take a lot of sales; something like 700 to 750 lb/ft of torque and focus on low end grunt with MPG savings and completely ignore high power outputs, save that for the HO diesels.

Then we'd have a good option between entry gas and completely bonkers diesel. I don't need to pull 35K pounds, but I'd love to pull 15K pounds at 15 to 20 mpg (pipe dream, I know, just sayin.)