342 vs 373 Real world experience

dbart · August 15, 2022

On 6/19/2022 at 1:12 PM, mandrewbot3k said:

@sheath, damn, that 7.3 powerband is impressive. That was going to be what I ordered if the local chevy dealer didn't have the L8T coming in so quickly.

@nards444I have a 2022 L8T, and I only have a couple gripes about it. But towing isn't one of them. It FEELS sluggish, but it's really not that bad. If you try to gas it while it's towing, it scoffs at you, and basically says, "I'll get there, gimme a minute, geez....". Going from a 1500 to a 2500, it just feels like I'm going slower than I am. When I'm cruising at 65 towing, it felt like I was going 40. Not a bad thing. The exhaust is pretty quiet on the L8T too, so I think thats part of the perception. My 5.3L seemed throatier and was noisier in the cab.

I'd say if you're only towing ~10x / year and worried about tow mileage , I think the fuel cost difference would be fairly negligible, especially relative to the extra $10k for the diesel. Definitely factor in that added cost when doing the fuel cost savings. If you only plan on having the truck for a few years and trading in, it may not be worth it to go duramax. If you plan on keeping for the long run, might pay itself off.

That said, I just towed combined weight of 16520, with 7240 on my trailer axle for 3 hours. I got about 8mpg, but it tows so nicely, especially compared to my 2019 5.3 1500 i just traded in. I don't have hill descent help, but i never really had to tap the brakes coming down grade, which was about 6-10%. It just held at 55mph and didnt struggle or anything.

I was able to get from 55-70 pretty easily to pass semis when needed, but I think those are the instance when I wouldve really felt the difference with the diesel.

Ultimately for me, I decided on the L8T over the duramax because 1) availability, 8 days from deposit to delivery and 2) my normal commute (getting about 11mpg) is pretty stop and go. I felt that would be bad on the diesel being in regen like 98% of the drive time, especially for an extra $10k. IU only tow my travel trailer about 10x year, so didn't seem worth it to me.

If you currently have a diesel, you might miss it. The other factor might be based on your driving routes. My full 36gal tank is only getting me about 400 miles tops probably on the highway, though I haven't done much of that driving. If you're running a long ways through barren land, it might be worth it to have the extra mileage of the diesel. But I really like the L8T.

Nice to hear you love the 6.6 gasser. I have a 2018 LTZ, CC SB 2500 Z71, Duramax and love it and it's paid for, but it might be going bye bye as I have had multiple things go wrong with it and I'm really thinking of getting a new 2022 GMC AT4 with the 6.6 Gas motor. My trailer loaded is about 5K, maybe 5500 lbs and I'm getting between 12-14 when towing. Straight freeway is 19-20's. In fact I did a run from home in Orange County, CA to Goodyear Arizona and back on 1 tank...just to see if I could. went 675 miles and could have made it to work and would have put just over 700 for a tank, but at fill up I got 19.85294 MPG for the trip. Probably won't see that with the 6.6 gas motor. But I'm hearing of issues with that 10spd trans for the new trucks, the diesel fuels are changing, (DO NOT RUN BIO_DIESEL) That is straight from a GM Tech, then there is the Def fluid, Fuel filter changes every other oil change, etc...

I have owned diesel since 2005 and absolutely love the torque and power but I know it is overkill for what I am towing.

16' box trailer that had a 2008 rhino in it, sold that...just picked up my 2022 CAN AM X-RS Turbo RR 2 seater. So I'm not towing a lot, in fact I could get away with a 1500...but No way I could step down after owning the 2500 series for so long.

I think I'm gonna go test drive one on the way home from work. Who knows...I'm on the fence...maybe end up with another diesel????

nards444 · August 17, 2022

On 8/15/2022 at 4:02 PM, dbart said:

Nice to hear you love the 6.6 gasser. I have a 2018 LTZ, CC SB 2500 Z71, Duramax and love it and it's paid for, but it might be going bye bye as I have had multiple things go wrong with it and I'm really thinking of getting a new 2022 GMC AT4 with the 6.6 Gas motor. My trailer loaded is about 5K, maybe 5500 lbs and I'm getting between 12-14 when towing. Straight freeway is 19-20's. In fact I did a run from home in Orange County, CA to Goodyear Arizona and back on 1 tank...just to see if I could. went 675 miles and could have made it to work and would have put just over 700 for a tank, but at fill up I got 19.85294 MPG for the trip. Probably won't see that with the 6.6 gas motor. But I'm hearing of issues with that 10spd trans for the new trucks, the diesel fuels are changing, (DO NOT RUN BIO_DIESEL) That is straight from a GM Tech, then there is the Def fluid, Fuel filter changes every other oil change, etc...

I have owned diesel since 2005 and absolutely love the torque and power but I know it is overkill for what I am towing.

16' box trailer that had a 2008 rhino in it, sold that...just picked up my 2022 CAN AM X-RS Turbo RR 2 seater. So I'm not towing a lot, in fact I could get away with a 1500...but No way I could step down after owning the 2500 series for so long.

I think I'm gonna go test drive one on the way home from work. Who knows...I'm on the fence...maybe end up with another diesel????

Kind of just did the same tow a 7-8k boat 3 months of the year and periodic heavy loads the etc cost of the diesel just wasnt worth it anymore, plus knocking 10k off the price allowed me to get a better truck.

With that said be ready the gas motor is not even close to a diesel. It does the job thats all I can say. And if I towed 5k or less and it was periodic I would really think about a half ton, motor performance will be the same as 2500 and new half tons in the last 10 years are a world apart from where they were.

Edited September 15, 2022 by nards444

Stand By · September 15, 2022

Don't know if I'd say the 6.6 scoffs at you while towing. It scoffs a little when you punk it while empty, as it's torque sensing. When I pull my boat, probably 8,000 ish with gear and fuel, you're over the speed limit before you realize it. 80ish on the freeway (empty) and the mileage is comparable to my previous 5.3 as I'm cruising at slightly lower rpms and both are bricks at those speeds. Freeway speeds make less difference on gearing, wind and rolling resistance govern your mileage. I researched this a lot back in the day when I had a 1st gen dodge Cummins with no overdrive. Trucks that kept the early highway gear and added the later overdrive, were not seeing much improvement. Most of the gearing benefit for better mpg'is at lower speeds and stop and go traffic. Might've went with another Cummins if they still used the 5.9, but very happy withy 6.6 gas. Except I'd like to be able to tune it to pay back my neighbor across the street with his loud 6.2 Camero. I starty days earlier than he does. Maybe I'll pull the boat around front and give him a taste of some 5.7 with marine wet exhaust.

nards444 · September 15, 2022

10 hours ago, Stand By said:

Don't know if I'd say the 6.6 scoffs at you while towing. It scoffs a little when you punk it while empty, as it's torque sensing. When I pull my boat, probably 8,000 ish with gear and fuel, you're over the speed limit before you realize it. 80ish on the freeway (empty) and the mileage is comparable to my previous 5.3 as I'm cruising at slightly lower rpms and both are bricks at those speeds. Freeway speeds make less difference on gearing, wind and rolling resistance govern your mileage. I researched this a lot back in the day when I had a 1st gen dodge Cummins with no overdrive. Trucks that kept the early highway gear and added the later overdrive, were not seeing much improvement. Most of the gearing benefit for better mpg'is at lower speeds and stop and go traffic. Might've went with another Cummins if they still used the 5.9, but very happy withy 6.6 gas. Except I'd like to be able to tune it to pay back my neighbor across the street with his loud 6.2 Camero. I starty days earlier than he does. Maybe I'll pull the boat around front and give him a taste of some 5.7 with marine wet exhaust.

Ill be honest this motor kind of sucks. Its ok for daily driving and thats why I got it. But it screams to get up to speed. Good luck empty passing somebody if your going 55-60 as it wont really move. Truck is really only good in initial start up to to 30-40mph after that its a dog.

Like I said if you really dont need a 3/4 ton I would go half ton, better gas, better performance and driving experience. 5-6k in towing or less dont bother with a gas 3/4.

Edited September 15, 2022 by nards444

KARNUT · September 15, 2022

Half ton trucks can be outfitted to handle up to 14k. Of course the trailer and it’s brakes would determine how I would feel about using a half ton. And the frequency. Unfortunately with GM you have to go way up model to get the right engine making the the 3/4 ton more attractive. But unfortunately for the GM enthusiast GM ranks last for heavy duty work. I back in the day shopped price and made adjustments to my truck with the savings. Acceleration numbers aren’t bad across the board. The feel of acceleration is dampen in a heavy truck. I got away from 3/4 ton and one tons as fast as I could. They were utensils as far as I was concerned. My real fun started with 1/2 tons.

Pryme · September 17, 2022

On 9/15/2022 at 7:46 AM, KARNUT said:

Half ton trucks can be outfitted to handle up to 14k. Of course the trailer and it’s brakes would determine how I would feel about using a half ton. And the frequency. Unfortunately with GM you have to go way up model to get the right engine making the the 3/4 ton more attractive. But unfortunately for the GM enthusiast GM ranks last for heavy duty work. I back in the day shopped price and made adjustments to my truck with the savings. Acceleration numbers aren’t bad across the board. The feel of acceleration is dampen in a heavy truck. I got away from 3/4 ton and one tons as fast as I could. They were utensils as far as I was concerned. My real fun started with 1/2 tons.

I went 3/4T 6.6 gas over a half ton mainly because I wanted a TRUCK. All the half tons are turning into suvs/luxury/sporty things with tiny 5.5’ beds. And they all have things I despise like afm, start stop, mds etc etc. with all of the above, the half tons are more expensive easily than a base or near base model 2500.

and so far my mileage is on par with my previous half ton anyway. It rides a bit stiffer but again, I wanted a truck. I reminds me of the 70’s and 80’s trucks I drove when I was younger.

Another JR · September 17, 2022

On 9/15/2022 at 4:54 AM, nards444 said:

Ill be honest this motor kind of sucks. Its ok for daily driving and thats why I got it. But it screams to get up to speed. Good luck empty passing somebody if your going 55-60 as it wont really move. Truck is really only good in initial start up to to 30-40mph after that its a dog.

Like I said if you really dont need a 3/4 ton I would go half ton, better gas, better performance and driving experience. 5-6k in towing or less dont bother with a gas 3/4.

Two comments:

i wonder if there is an issue with your truck. Mine passes, accelerating from 55 to 70, on the highway very briskly with 2000 lbs of pop up camper in the bed. I’m very comfortable making passes on two lane highways. Your description of the power you get in that situation seems very different from what I experience.

One of the times I most appreciate the heavier duty truck is when I have to brake really hard at highway speeds. I’ve had three serious panic stop situations so far in this truck, each time with the camper on, and it stops really fast under complete control.

Pryme · September 17, 2022

58 minutes ago, Another JR said:

Two comments:

i wonder if there is an issue with your truck. Mine passes, accelerating from 55 to 70, on the highway very briskly with 2000 lbs of pop up camper in the bed. I’m very comfortable making passes on two lane highways. Your description of the power you get in that situation seems very different from what I experience.

One of the times I most appreciate the heavier duty truck is when I have to brake really hard at highway speeds. I’ve had three serious panic stop situations so far in this truck, each time with the camper on, and it stops really fast under complete control.

Do you feel like the brakes are a bit weak/soft feeling when just coming to a stop sign when trying to brake lightly? I’ve yet to have to apply any serious power to the pedal but under light braking it feels sluggish ha

Another JR · September 17, 2022

1 hour ago, Pryme said:

Do you feel like the brakes are a bit weak/soft feeling when just coming to a stop sign when trying to brake lightly? I’ve yet to have to apply any serious power to the pedal but under light braking it feels sluggish ha

The feel of my brakes was pretty good from the start, but early on I did the procedure several have recommended on here to firm up the pedal feel, and it did improve somewhat (again mine already felt fine, whereas other have complained of a spongy feel.

With the truck running and in PARK, push the brake pedal slowly and firmly as far as you can with large but not stupid force. Let it all the way up, then press it the same way again. I don’t know, but I suspect the reason this sometimes improves the feel is that it clears a bubble in the master cylinder left behind due to the factory filling a dry system and using a power bleeder rather than old fashioned pedal stroke bleeding.

Pryme · September 17, 2022

2 hours ago, Another JR said:

The feel of my brakes was pretty good from the start, but early on I did the procedure several have recommended on here to firm up the pedal feel, and it did improve somewhat (again mine already felt fine, whereas other have complained of a spongy feel.

With the truck running and in PARK, push the brake pedal slowly and firmly as far as you can with large but not stupid force. Let it all the way up, then press it the same way again. I don’t know, but I suspect the reason this sometimes improves the feel is that it clears a bubble in the master cylinder left behind due to the factory filling a dry system and using a power bleeder rather than old fashioned pedal stroke bleeding.

That can’t work it’s a sealed system so the brakes can’t be bled without cracking a fitting open. As far as I know at least?

Another JR · September 18, 2022

5 hours ago, Pryme said:

That can’t work it’s a sealed system so the brakes can’t be bled without cracking a fitting open. As far as I know at least?

Think about how the fluid from the reservoir enters the system as your pads wear and the pistons extend more. When the pedal is fully released, the brake circuits in the master cylinder are connected to the reservoir. That’s why you are able to use a power bleeder. Pull up a diagram of a master cylinder to visualize it. I’m speculating it may be a bubble in the master cylinder and pressing hard to stroke the master cylinder a greater distance shifts the bubble so it works it’s way back to the reservoir. Completely a guess though.

Pryme · September 18, 2022

11 minutes ago, Another JR said:

Think about how the fluid from the reservoir enters the system as your pads wear and the pistons extend more. When the pedal is fully released, the brake circuits in the master cylinder are connected to the reservoir. That’s why you are able to use a power bleeder. Pull up a diagram of a master cylinder to visualize it. I’m speculating it may be a bubble in the master cylinder and pressing hard to stroke the master cylinder a greater distance shifts the bubble so it works it’s way back to the reservoir. Completely a guess though.

Guess it couldn’t hurt to try.

KARNUT · September 18, 2022

23 hours ago, Pryme said:

I went 3/4T 6.6 gas over a half ton mainly because I wanted a TRUCK. All the half tons are turning into suvs/luxury/sporty things with tiny 5.5’ beds. And they all have things I despise like afm, start stop, mds etc etc. with all of the above, the half tons are more expensive easily than a base or near base model 2500.

and so far my mileage is on par with my previous half ton anyway. It rides a bit stiffer but again, I wanted a truck. I reminds me of the 70’s and 80’s trucks I drove when I was younger.

My first 1/2 ton was a 70 Ford pickup it was bare bones but did the job. In contrast my father had a 70 CST 402 with a tac dash. Hugger Orange with a black top. It was pretty sporty. At the same time my mother drove a Electra 225. When they went somewhere together they took the truck. So my memory is trucks could be pretty sporty. Until fairly recently 3/4 tons were rated at what 1/2 tons are rated now. Chevys problem is you have to go up model to get the 6.2. The competition last time I checked you could get their bigger engine in a work truck. GM does hand cuff your choices more than the competition. Medium duty work can easily be accomplished in a half ton. So can the best of both worlds.

Edited September 18, 2022 by KARNUT

nards444 · September 19, 2022

On 9/17/2022 at 11:30 AM, Another JR said:

Two comments:

i wonder if there is an issue with your truck. Mine passes, accelerating from 55 to 70, on the highway very briskly with 2000 lbs of pop up camper in the bed. I’m very comfortable making passes on two lane highways. Your description of the power you get in that situation seems very different from what I experience.

One of the times I most appreciate the heavier duty truck is when I have to brake really hard at highway speeds. I’ve had three serious panic stop situations so far in this truck, each time with the camper on, and it stops really fast under complete control.

Maybe. But i have driven other gas trucks in the past and it seems on par tbh. Just compared to a diesel or half ton its really slow all around.

Stand By · September 21, 2022

On 9/15/2022 at 7:54 AM, nards444 said:

Ill be honest this motor kind of sucks. Its ok for daily driving and thats why I got it. But it screams to get up to speed. Good luck empty passing somebody if your going 55-60 as it wont really move. Truck is really only good in initial start up to to 30-40mph after that its a dog.

Like I said if you really dont need a 3/4 ton I would go half ton, better gas, better performance and driving experience. 5-6k in towing or less dont bother with a gas 3/4.

I have a different experience. I tow similar to you. 5000lb boat, dru weight+trailer,fuel and gear pushing towards 10,000. Night and day from my previous 5.3 4 door. Empty, the 5.3 gets better around town. On the freeway, they're comparable, except the 6.6 HD is way more stable and accelerating to pass at speed limit+ is much quicker in the 6.6. It is doggish getting out of the hole, due to being torque sensing and not giving full torque without a load behind it.