7.3 vs 6.6 GM gasser

Nazz112

Tremor Junkie
Joined
Feb 2, 2021
Messages
871
Reaction Points
1,374
Location
Mountains
Current Ride
2022 Lariat Tremor 6.7
Current Ride #2
Tesla Model 3 Performance
Curious to hear if anyone came from 6.6 gas and can give their opinion on how it stacks up with 7.3. Also please confirm the 6.6 had 10 speed so its more apples to apples
 
Bump
 
Apples to apples is going to be really tough to come by. It's not just the transmission, but you'd have to control for a comparable weight (trim/options vary considerably), tires, and rear end gear ratio to really be comparing the engines themselves.

My good friend has a 6.6 on his 2500. It's a '22 so I'm pretty sure it has the 6-speed (only option) and 3.73 rear end. It's an fairly basic LT with stock highway-biased tires (less than 33" I believe). It tows his ~9k travel trailer up over the mountains well enough, but I think he'd agree my Tremor pulls notably stronger, despite being a fair bit heavier and with much bigger tires. Those factors are offset by the 4.30 gearing and 10-speed.

There isn't too much to have to speculate on, however. If you put the same transmission and gearing behind the 6.6L in a truck with same weight and tires, the 7.3L is still going to pull harder. It makes more torque, earlier in the powerband, and stays much flatter. No replacement for displacement, as they say....

Conversely, you'd probably observe a bit less fuel than the similarly-equipped 6.6L for the same reasons.
 
I drove my dads 6.6 10 spd to Washington and back in November. I have a 7.3 10 spd. I believe his is 3.73 gears, and mine is 4.30. I drug a 12’ utility trailer there and back empty on th way up, and about 600 lbs with a windsock on the way back. I averaged 12.8 round trip hand calculated running 80-85 the entire way. I would be lucky to get 12.8 on my 7.3 running that fast with no trailer. There’s no comparison on power though. The 7.3 pulls better and has more low end torque. My truck is more enjoyable to drive for sure, but that mileage made me question the 6.6. Running 80 with the trailer I’d be looking at 10 mpg in my 7.3.
 
That sounds about right. Have done that drive several times. Usually 13.7 on the way up, and about 12.9 on the way back due to the E-W elevation gain/loss.

With travel trailer or enclosed, more like 8.3 overall.

With an open flat trailer, I’d wager you could certainly stay up near 11. And it you had 3.73 over the 4.30 you could expect another 1 MOG at least.

Regardless 7.3L is bigger, so notably power, and notably more fuel.

The new 6.8L would be a better comparison for the 6.6L in both regards.
 
I saw a ZR2 in person and it looked very nice. I would like to drive one to see how they compare. Local dealership had a diesel Zr2 but not gas. I also like how they are truly lifted from factory, not like Tremor where ford put bigger tires on it and say it’s lifted lol. And for all you that don’t know it’s true do your research. They have .5in taller front springs and the other 1.5in is tires.
Also not bashing I’m a Ford guy and have had two Tremors which were/are great. But the ZR2 looks to be a step ahead of the Tremor in off-road design and looks especially the 23/24 as they have a face only a mother could love.
 
I saw a ZR2 in person and it looked very nice. I would like to drive one to see how they compare. Local dealership had a diesel Zr2 but not gas. I also like how they are truly lifted from factory, not like Tremor where ford put bigger tires on it and say it’s lifted lol. And for all you that don’t know it’s true do your research. They have .5in taller front springs and the other 1.5in is tires.
Also not bashing I’m a Ford guy and have had two Tremors which were/are great. But the ZR2 looks to be a step ahead of the Tremor in off-road design and looks especially the 23/24 as they have a face only a mother could love.
Wait until you try the Multimatics :ROFLMAO:

I look forward to your comments after you drive one. I assumed you already had.

Some eye candy for you:

20240502_113404.jpg


IMG_20240503_193925.jpg
 
😂
I had a 2017 2500 Denali Diesel
They do look good! Minus mirrors
I have never been opposed to the aesthetic of the GM mirrors, but understand many here are. I will say, on washboard surfaces, they shake like a mutha, especially when extended. But those 2 things aside, I give Ford huge props for the visibility out of the front windows. The trademark door dip, + the less cumbersome mirror structure, make visibility much better.

1 week in with my F250 Tremor and mostly love it. Biggest difference to my GMs is the seat comfort and ergonomics. Anyone could adjust a Ford seat, mirrors, pedals, and steering wheel and love it. Some of the interface stuff has me scratching my head. I'll make a separate post at some point. Pros and cons with both, of course.
 
Mirrors, square fender wells, and goofy fake hood scoop. Not a big fan of the grill either, but to each his own.
My 2017 had a functional hood scoop
 
the zr2 and at4x are very nice. good luck finding a gas one. i could not find a '24 gm gas in a higher trim; at4x, at4, zr2, or ltz sport any where remotely close to me. i didn't want to order either because i didn't want to wait and my truck was essentially sold to my buddy. if i could have found one in a trim level and color i wanted, i would be in a gm still.
anyway, here we are in the ford 7.3. it is a nice truck, but the tranny is all over the place and there are various clunks/pops here and there. my 2020 was the same, so it is the nature of the beast. both my 2020 gmc and 2022 chevy 10 speeds were much more refined than the fords.
 
I thought the transmission for ford and gm are the same. With exception to torque converter each using their own and valve bodies
 
I thought the transmission for ford and gm are the same. With exception to torque converter each using their own and valve bodies
no. 1/2 ton 10 speed was a collaboration.
HD trucks are completely seperate/different
 
Ok good to know 😃
 
The GM 10-speed and Ford 10-speed architectures are similar and based on the lighter-duty calibration. There are differences just like there are differences on the calibrated lighter-duty version.
 
I have only a few hundred miles on my new Tremor F250. The transmission has been delightful and I hope it stays that way. I test drove 4 different F250 Tremors before mine (1 diesel just to try, 3 different 7.3L) and 3 of them had a noticeable lurch forward between 1-2. I posted on it at one point. Not sure why mine does not do the same, but naturally I'm super pleased with a "good" one. Truck was built on 4/17.

The GM HD tranny is different than the Ford, and is very smooth. With their smaller 6.6L V8, the truck really benefits from the 10 speed.

The AT4X I custom ordered (and then passed on) arrived to my dealer on 4/2. It just sold a few days ago, so it was available about 7 weeks. There are 2 other ZR2 gassers in my area, one has the AEV package. Both of these trucks are much rarer beasts, as they just started hitting dealers in late 2023 and they are separate trim levels. HD Tremors I see everywhere, understandably. The white ZR2 I posted above, it was one of 2 gassers at an Iowa Chevy dealer on the lot and ready to go.

If I had to state the biggest attribute / clear win for each truck after only 7 days of Ford ownership:

Tremor 250 - much better interior comfort and ergonomics
ZR2/AT4X 2500 - much better steering and handling

No regrets so far with my Ford. But the ZR2 remains on my mind.
 
Have you seen the TFL video where the Ford does the Ike Gauntlet in the same time as the 6.7, and the Chevrolet 6.6 transmission gets to 240+ degrees and they're talking about having to shut it down to cool off while also being about 50% slower than the diesel. It's a good video, and all I needed to know about the 6.6 no matter how much I like how they look. If you're going HD Chevrolet definitely go diesel.
 
Last edited:
My buddy, took ownership of a 24 Zr2 gasser at the beginning of the month. I didn't have time really to talk with him at that time about it. (It was a funeral)
He has been a chevy guy his whole life, as I have been a Ford guy. This weekend we all went camping. After too many cocktails, he admitted that he loved the look of my Temor, why he ordered the Bison. I have to say it is a very nice truck. I do like some of the features. Stock he has more "body armour" but said it was aluminum. Take it for what it is with modern tec. The other thing it did have a little more ground clearance about an inch. We did break out the tape measure.
So being a little to intoxicated, we hit the DNR trails, along with a couple side by sides and a few 1/2 tons 2014-2020. We both had the same issues of turning radius, even with turn assist.
As for everthing else, other than "mine is better because it's mine thing" they are every very similar. I guess he might have had an argument about his up front suspension. We got these to pull campers, look cool, and 2 track when drinking, because, well, we do guy shit.
As for pulling, we didn't do a chain the axles together thing, but I pulled his camper around the camp ground, and he pulled mine I was a just over 9800lb and he was around 13,500. Didn't feel much diffrent truck to truck. While I don't know about others, his did have the Allison 10, and it shifted about the same as mine.
If you are a chevy guy or don't care. They are very similar.
I'm sure the super hard corp will talk about the 1 degree here the .002 seconds faster zero 60 or extra 6lb you can haul in the bed. I'm definitely not that guy.
Now if only GM could figure out wheels are round and so should the wheel wells!
Hope this helps.
 
Last edited:
Back
Top