Chevy Express/GMT610 6.0/6L90e vs 6.6/6L90e vs 6.6/8L90e

[wrath]

Decades long lurker, first time poster.


I'm familiar with Class A and some weird old stuff like 73-78 GMC transmodes. I'm also familiar with bumper pull.



I'm familiar with GM powertrain, including both the new and old 8L90e.



Has anyone spent significant time in a Class C with the 6.0/6L90e, 6.6/6L90e, and 6.6/8L90e? Are they all the same loudness as perceived by the earbearer? I'm curious if the new ones are all loud versus the prepandemic cutaways or I've only been lucky to drive loud ones.





Some background:



I'm going to focus on Forest River products, mostly because they seem to have the most Chevy chassis out there. Thor isn't afraid of them either, but Thor won't spend the money to buy the more expensive Chevy Chassis and I don't blame them because the 8L90e cutaway is expensive. It'd be nice to have the option though. I cornered a sales rep at a Camping World and made him call and find out if they were going to have any more Chevy Class Cs. The answer was no for the 2025 model year.



I'm looking to migrate to a smaller footprint Class C that can flat tow a Wrangler. Ford is out because my feet don't fit. I'd consider a Super C, preferably on GM 5500 Silverado, or a Freightliner S2, but they're rare in a short length (under 30').


Ideally I'd like something like a Coachmen Freelander/Leprechaun 26DS/260DS but they quit making them on a Chevy chassis long ago. Decent length (28' depending on how you measure, 191" wheelbase) and checks all the boxes. Also from Forest River is the 2551DS, but while still in production... super rare.


I'd also consider a Coachmen Freelander/Leprechaun 23FS/230FS. About 26' and 177" wheelbase. Not quite as ideal in wheelbase to overall length ratio but still OK.


Towards the tail end of 2023, GM switched from the 6L90e to the 8L90e version 2 in the Express chassis. There are a ton of 2024 and 2025 Class Cs for sale with these 2023 chassis in both 3500 and 4500.


I am familiar enough with the circa 2019ish 6.0/6L90e Class Cs. I swear they seem quiet, but I might be dreaming it.



I have only driven one 6.6/8L90e and it was a Thor Freedom Elite 22HZ. It is a short 24' and doesn't weigh much. It was like riding around in a little rocket ship. But it was deafening inside. Not just from the reaction shell in the transmission, but it was wind noise also.



I'm wondering if I should buy a used 260DS from circa 2020 or buy a new 230FS with either a 6 speed or 8 speed. I'd rather have the space of the 260DS but that's it. I was ready to buy a 230FS or something like it, but the first 6.6L/8speed I drove was very loud inside at expressway speeds.
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[atreis]

Mine is a '21 coach on a '20 chassis with the 6.0 engine. The noise isn't too bad, but I don't have a lot to compare with and haven't driven one with the newer 6.6. I love the Chevy chassis handling, so if Thor is no longer offering it that's a real shame.

[wrath]

Originally Posted by atreis

Mine is a '21 coach on a '20 chassis with the 6.0 engine. The noise isn't too bad, but I don't have a lot to compare with and haven't driven one with the newer 6.6. I love the Chevy chassis handling, so if Thor is no longer offering it that's a real shame.

Yeah, I'm hoping someone has driven all of them to see if I'm missing something. I really don't want to go deaf driving the motorhome. And since they're so rare and hard to find anyway, I have to go 500 miles to get what I want and don't want buyer's remorse.






The Chevy chassis is a little bit better (less wet noodle frame, better sway bars, less spring, AAM axle), but comes with lower ratings for the dollars spent over a Ford chassis. Ford is usually about 10% cheaper wholesale. So why would a manufacturer choose to buy something that few motorhome buyers care about (most shop on the house, not the chassis)? I don't blame them, but it doesn't mean I wouldn't spend more for a Chevy chassis.


There was a brief period when Ford finally abandoned the 6.8L V10 where the 7.3L Gasser was murdering the 20 year old GM 6.0L. But then the GM 6.6L Gasser came along and wasn't derated (Ford severely detunes the E350/E450 chassis engines). Ford also missed the opportunity to fix the terrible cockpit/doghouse in the cutaways. Then GM put the 8 speed behind the 6.6L and anyone that drives a cutaway/box truck or ambulance or RV back to back will never pick the Ford.


Thor is cheap. There has been issues with International (used to be Navistar... where most GM cutaways are made) which is owned by the same holding company as VW. Remember that Navistar was the maker of the old PowerStroke engines until Ford got tired of all the problems. Then International started using the Duramax in their medium duty trucks when they couldn't get an affordable Cummins. There was a period for a few months at the end of 2023 you couldn't order GM cutaways. That's when a lot of coach makers want to buy them. Plus they got more expensive after the 8 speed went in anyway.


It gets even more dicey with regard to International/GM in the fact that VW also owns the company that owns Scout Motors (the electric truck/SUV vehicle piece for VW) and International also makes its own electric trucks... but still does a lot of business with GM. And GM went after the medium duty truck market with the Silverado class 5 and 6 trucks...


There is a lot of information on the GM upfitter website for your model year chassis:
https://www.gmupfitter.com/body-builder-manuals/