10 Speed Allison vs 6 Speed MPG

[mtbadbob]

I was wondering if any member has had both trans and know what the supposed "increase" in mpg's is??? I'm guessing 3/4-1 mpg? I'm calculating that at that rate, one would save like $250-$300/yr in fuel, driving approximately 18k a year? I'm trying to justify the purchase of the '24 I ordered when the trade diff is about $20K.

UPDATE: Sorry, the search window on this forum is as worthless as all the pop-ups! I see there has already been a post about this topic, ALTHOUGH search results came up with ZERO! FFS!

Edited November 14, 2023 by mtbadbob

[64BAwagon]

I had a 2021 and now have a 2024 that are almost identical. So far I havent noticed any real change but I dont have a lot of miles on my 2024 and none towing. I have some towing coming up so that will tell the tale. I do think that a 3/4-1 mpg improvement is being a little optimistic. pulling my fifth wheel a wind speed or direction change would net me more than that. Theres so many factors affecting MPG while towing that its hard to compare. If I see anything over 1/4 mpg I will be pleased. 

[Pryme]

No difference. Plus the 24’s still have those pesky water drain holes in the tailgate that require silicone to be slathered all over the whole rear end of the truck. 

[2021 HD]

My 2010 with the 6.0 and 6 speed got at best one time 13 mpg around town. Most of the time it was about 12.5. My 2024 6.6 10 speed is getting almost 13 around town and it is not even close to broke in yet. I think it will be close to 14 after it is broke in. The truck also is about 1300 lbs heavier.

[Doodle]

Had a 23 put 15K on now have a 24 with 10K.  Mileage is about the same.  My 23 was an SLE and weighed about 7150 lbs.  My 24 is an AT4 and weights a tad over 7500 lbs plus it has the 20” tires.  So given that I’m glad it’s about the same as the 6 speed.  I would not pull the trigger just for mileage.  The 10 speed is just a more refined trans and is just makes the power so much more useable.  The more miles I put on the better I like it.  Butter smooth shifts too.  My 23 took to about 10K to get broke in so the mileage could go up a tick, but I”m guessing very minimal.  

[reb0957]

On 11/14/2023 at 6:08 PM, Pryme said:

No difference. Plus the 24’s still have those pesky water drain holes in the tailgate that require silicone to be slathered all over the whole rear end of the truck. 

Water drain holes?

[Pryme]

2 hours ago, reb0957 said:

Water drain holes?

Well it’s kinda an ongoing joke but yeah, there are two small rain holes located at the top of the tailgate. In a perfect spot to allow water to drain onto the electrical switches for the tailgate release. Kind of a boneheaded thing if you ask many on here. Plenty of us have sealed them with silicone. 

[Jettech1]

34 minutes ago, Pryme said:

Well it’s kinda an ongoing joke but yeah, there are two small rain holes located at the top of the tailgate. In a perfect spot to allow water to drain onto the electrical switches for the tailgate release. Kind of a boneheaded thing if you ask many on here. Plenty of us have sealed them with silicone. 

I still have not done that. lol...I need to send myself an email at work so I can do it tomorrow on my break.  I keep forgetting about it.

[Pryme]

7 hours ago, Jettech1 said:

I still have not done that. lol...I need to send myself an email at work so I can do it tomorrow on my break.  I keep forgetting about it.

You’ll remember when your tailgate goes wonky on you ha jk

[64BAwagon]

I pulled the inner panels off of mine and coated the entire inside with Fluid film. 

[Jettech1]

4 hours ago, 64BAwagon said:

I pulled the inner panels off of mine and coated the entire inside with Fluid film. 

I unexpectedly have a 3 day weekend starting today so I think I'll do that first and see just how bad it looks inside before I plug those holes.  Fluid film is a great idea, thank you!

[the8rotor]

3 hours ago, Jettech1 said:

I unexpectedly have a 3 day weekend starting today so I think I'll do that first and see just how bad it looks inside before I plug those holes.  Fluid film is a great idea, thank you!

One more thing to do on my truck as well now

[64BAwagon]

1 dozen or so T15 screws is all thats stopping you. 

[mtbadbob]

On 11/14/2023 at 5:08 PM, Pryme said:

No difference. Plus the 24’s still have those pesky water drain holes in the tailgate that require silicone to be slathered all over the whole rear end of the truck. 

No way am I doing that to my new '24!!!

[Jettech1]

1 minute ago, mtbadbob said:

No way am I doing that to my new '24!!!

I'm glad you are taking it in a nice way that your post was totally hijacked by someone I won't name... @Pryme.  I never did like him, pesky little person.  Anyhow you may want to seal those holes up...goodness knows we don't want moisture where it shouldn't be.... LOL.....  Damn you Pryme....