Feel good story about the L8T towing heavy

diyer2 · December 3, 2021

10 to 18 gears is the norm for a semi. There is a reason. Helps keep the motor in the power band when towing.

Our 8 speed car does better in our mountains than my 6 speed truck.

mrjulian416 · December 3, 2021

9 hours ago, nick112288 said:

I don't think your comparison between the 6.6 and 7.3 was quite what you meant it to be.

A much larger displacement engine, with noticeably more power and a 10 speed, gets the same mileage as a smaller, less powerful engine using a 6 speed.

Technically that would point out why the 10 speed is better.

Technically.. maybe. Easy to draw that conclusion though. In 90%+ of my driving (and probably most people's), the available ratios of the 10 vs the 6 wont make enough difference in practical application for me to conclude I should've waited for the 10 speed. The Ford 10 speed typically skips 2 and 4 (and sometimes 6) in unloaded, normal acceleration. When towing or heavily loaded, sure the 10 speed can be an advantage.

Edited December 3, 2021 by mrjulian416

Ray Pickle · December 3, 2021

Power band of most diesel engines are much narrower than that of gas engines that is why they traditionally have more ratios. A 10 speed in a h.d. gasser may offer incremental improvements in drivability and efficiency possibly at the expense of long term reliability. The constant shifting/ potential hunting is what causes heat and we all know what heat causes in an auto trans.

Grjfer · December 4, 2021

With the 6 vs 10 speed argument a trend I see especially with GM is the more transmission gears the higher the rear gear ratio. I have had several gas 1500 trucks. A 5.3L 4 speed with 3.73 rear end, pulled really well, not the best mileage but acceptable. A 5.3L 6 speed with 3.42 rear end. Pulled acceptable and mileage was decent. 6.2L 8 speed with 3.23 rear end. Pulled somewhat lack luster, but 6.2 made it tolerable and milage was great. I understand my 2500 is a different platform made for pulling /towing. I find the 6.6 gas with 6 speed and 3.73 to be the best combination for pulling/towing for me with acceptable mileage.

The diesel vs gas debate gets plenty of fan far, but for me the up front cost difference, maintenance cost and the cost at the pump means I can drive a lot of miles before, if ever making up the cost differences.

JCamper · December 12, 2021

On 12/1/2021 at 11:22 AM, mrjulian416 said:

There's not a lot of traffic in this subform so I thought I'd share a nice, real world story about the gas 2500HD ('21 CCSB SLT).

In late Oct a friend of mine bought a new track loader for use in managing his forestry property (ASV... 'nice'). He was without a HD truck at the time so asked for my help with picking it up from the dealer. Basically a 9000lb machine, on a 3500lb flatbed (not gooseneck), with a ~2000lb cutter head.

Drove about 90 minutes from his place to the dealer, country roads and interstate, central NC, flat and some rolling hils. Loaded things up, strapped things down, pulled out. I can honestly say, at max rating I was expecting the truck to have to work harder than it did. Not at all saying "you didn't know it was back there", but I was surprised at how well it handled a max conventional tow load. Shifts were smooth, not harsh. It accelerated fine when merging onto the interstate, didn't sound like it was screaming at redline. Once on the highway rolling 70mph, it was solid, smooth, planted. There was power enough to accelerate into the left lane to get around slower traffic, etc. Slowing and stopping was uneventful. The trailer had electric brakes which of course played a big part, and the built in brake controller just worked, no drama.

90 minute drive home, that last 20 of which was on country roads. The trailering app showed a combined round trip mileage for this "guest trailer" of 8.1 mpg. I get similar mileage pulling my 9k boat and trailer, which seems about rights since a boat with a t-top is a much larger sail than a track loader.

Moral of my story... if you need to pull heavy, the 6.6 gas will get it done. I admit if you pull heavy all the time, diesel is probably the right answer. But as a guy with his first 3/4 ton truck, I continue to be amazed that the experience of towing, even at max rating, is so much better than any half-ton (at any weight).

JCamper · December 12, 2021

Hello and thank you, I am new here. We just purchased a used 2020 GMC 2500HD 4x4 crew cab. We tow a 36 ft travel trailer. I also have a 96 Chev K3500 that I was towing it with and it did just fine. But being a Michigan truck with only 103K miles on it, I was leery of towing it long distances even though I completely upgraded the cooling system, new brakes in the front inc: pads, rotors, calipers, hoses and rotors. Also new front wheel hubs, shocks and stab links. New rear brakes and lines. New tires even though they had 60-70% tread left, they started to crack in the tread. I bought this truck new way back when.

I feel very confident this new to us 2020 will do the job just fine. The travel trailer weighs 7100 lbs dry. We do not carry fresh water with us and the waste tanks are always empty. We use full hook up camp grounds.

Looking forward to following this forum.

Joe

Dunn · December 23, 2021

Would you rather have the 6.2 motor in current 10spd or a 6spd?....

Never experienced where more gears hurt more than it doesn't help.....

I would take 10spd.....am sure it be properly calibrated if it comes out

Ray Pickle · December 23, 2021

5 hours ago, Dunn said:

Would you rather have the 6.2 motor in current 10spd or a 6spd?....

Never experienced where more gears hurt more than it doesn't help.....

I would take 10spd.....am sure it be properly calibrated if it comes out

Apples and Oranges

sheath · December 27, 2021

Red Delicious or Fuji?

Purely speculative on my part, but the 10 speed could have implications on engine mapping, which could both increase fuel mileage, and decrease emissions. From that point, it could be very beneficial.

Even with that, I'm happy with the six speed. Sometimes "good enough" is good enough for me. Other times, I like the newest tech available. I'd dig having a 5G hotspot in the truck. But if they had a 10G, well... sign me up! :cheers:

On a side note, I wonder how long it will take the EPA to catch up with creating Fuel mileage standards for the 3/4 & 1 ton markets? I'm surprised the 3/4 ton isn't already there.

Stand By · December 31, 2021

On 12/27/2021 at 5:57 PM, sheath said:

Red Delicious or Fuji?

Purely speculative on my part, but the 10 speed could have implications on engine mapping, which could both increase fuel mileage, and decrease emissions. From that point, it could be very beneficial.

Even with that, I'm happy with the six speed. Sometimes "good enough" is good enough for me. Other times, I like the newest tech available. I'd dig having a 5G hotspot in the truck. But if they had a 10G, well... sign me up!

On a side note, I wonder how long it will take the EPA to catch up with creating Fuel mileage standards for the 3/4 & 1 ton markets? I'm surprised the 3/4 ton isn't already there.

They get an allowance for all vehicles they make combined and are allowed offset unused credits to other vehicles.

sheath · January 2, 2022

On 12/31/2021 at 1:07 PM, Stand By said:

They get an allowance for all vehicles they make combined and are allowed offset unused credits to other vehicles.

Yes, i understand the current laws, but also understand that current standards are always being challenged. With the rise in personal use of the 3/4 & 1 ton trucks, it's only a matter of time.

L8T · January 16, 2022

On 12/1/2021 at 10:48 AM, C/K Man said:

GM needs to make the L8T available in the Silverado 4500/5500/6500. I hear it's eventually coming when they pair the L8T with an Allison transmission.

This will never happen. The Allison is heavy internally and will rob too much hp to make it viable. Not to mention awful fuel economy. Hence why they dropped the 8.1/ally combo years ago.

kenny_r · January 17, 2022

You don’t go up a mountain 3 minutes faster than the competition having an extra 29hp and 10 ftlbs. Transmission/gear ratios played a huge role in the outcome of that race. I’d be far more worried about transmission problems in a 10 speed vs 6 speed though so maybe they just need to option a 4.10 with the 6.6 for those folks who don’t care about getting an extra 1 mpg.

Another JR · January 17, 2022

There was a lot more influencing that test result than number of transmission gears.

Ray Pickle · January 17, 2022

14 hours ago, kenny_r said:

You don’t go up a mountain 3 minutes faster than the competition having an extra 29hp and 10 ftlbs. Transmission/gear ratios played a huge role in the outcome of that race. I’d be far more worried about transmission problems in a 10 speed vs 6 speed though so maybe they just need to option a 4.10 with the 6.6 for those folks who don’t care about getting an extra 1 mpg.