The Biggun - GMC 3500HD AT4
Discussion
Needed something to pull some large trailers for Sista D - Solution is the new 2025 GMC 1-ton truck running a Duramax 6.6L (pushrod) turbo-diesel V8 weighing in at over 3 tons (or 7,200lbs in freedom units).
(Caveat this is my first large truck).
Details:
With options, taxes, registration, delivery, engine choice, and accessories the total came in at slightly over 98k USD
Insurance was a pretty reasonable $260 a month
Stock height of about 7ft, 20ft long and over 8ft wide with wing mirrors extended (the wing mirrors can move out an additional 6 inches each side)
8 Leaf sprung suspension on rear
5th Wheel (smaller version of the articulated lorry connector) in the truck bed for towing.
32,000 lbs towing capcity
10 speed slush box
470 HP and 975 LB-FT
6.9s 0-60. Although previous models were in the 6.5 second range.
Realistically around 15mpg, although towing can take that down to about 7/8mpg (don't forget US gallons are 4L vs 5L UK gallons)
Aux Engine heater
Engine exhaust brake
Bose sound system
Head up display
Under vehicle lighting
Adjustable brake bias for electroincally controlling the trailer brakes (this is apparently normal to have on trailers over here so you can dial-in how much brake effort they produce).
First Good Impressions:
Subjective, but I think it's the best looking heavy duty truck out there.
External and underbody lighting looks great at night - albeit does resemble a tow-truck with all the orange lights on the roof.
I see why people like the high seating position - way higher than the large vehicles I've driven in the UK like box vans. Certainly feel quite protected. Nearly a foot of ground clearance.
Feels really solid and surprisingly quiet on the highways
The truck bed is huge.
Really like the heads-up display - still think it's magic how it looks like it's a foot in front of the bonnet.
13.4 inch display and really like the option to edit the info on the drivers display like showing gearbox temps etc.
Actually not an awful turning circle - definately better than a 110 landy.
Lots of cameras (including truck bed camera) and can be used while driving (wish car companies would allow the feed to be recorded like Teslas). Also option to install additional cameras on the trailer which integrate into the display.
Still running in, but lots of tourque on tap
Tons of storage areas in the cabin.
Wide enough center console that our dog's bed can comfortably fit there.
6 position tailgate is split and has speaker/lights options along with 110V outlets. (Also has 110V outlets in the cabin too).
Lots of USB & USB-C ports
Keeps a history of trailer settings for different trailers.
Video rear-view mirror - this apparently has a 'transparent' mode so you can see-thru the trailer you are towing.
First 'questionable' Impressions:
It is the size of a box van
Mirrors are massive and actually block vision out the side windows when turning.
Parking is a bit of a mare in tight spaces.
The brake pedal is quite spongy and has a long travel.
You can really really feel the weight when driving.
Not a fan of the retractable foot steps. I think fixed ones look better imo.
Apparently not that difficult to nick, so need to get the USA equivalent of a Ghost fitted.
GMC apps are a bit flaky and only give you 1 month's trial included.
The ride is pretty harsh with the leaf-spring suspension. Road humps have to be taken at a very low speed.
Not specific to this car, but I hate column shifts on vehicles
Regrets?
Yeah I should have ignored warnings about getting a bad back (from the even more harsh ride) and got a dually : )
(Caveat this is my first large truck).
Details:
With options, taxes, registration, delivery, engine choice, and accessories the total came in at slightly over 98k USD
Insurance was a pretty reasonable $260 a month
Stock height of about 7ft, 20ft long and over 8ft wide with wing mirrors extended (the wing mirrors can move out an additional 6 inches each side)
8 Leaf sprung suspension on rear
5th Wheel (smaller version of the articulated lorry connector) in the truck bed for towing.
32,000 lbs towing capcity
10 speed slush box
470 HP and 975 LB-FT
6.9s 0-60. Although previous models were in the 6.5 second range.
Realistically around 15mpg, although towing can take that down to about 7/8mpg (don't forget US gallons are 4L vs 5L UK gallons)
Aux Engine heater
Engine exhaust brake
Bose sound system
Head up display
Under vehicle lighting
Adjustable brake bias for electroincally controlling the trailer brakes (this is apparently normal to have on trailers over here so you can dial-in how much brake effort they produce).
First Good Impressions:
Subjective, but I think it's the best looking heavy duty truck out there.
External and underbody lighting looks great at night - albeit does resemble a tow-truck with all the orange lights on the roof.
I see why people like the high seating position - way higher than the large vehicles I've driven in the UK like box vans. Certainly feel quite protected. Nearly a foot of ground clearance.
Feels really solid and surprisingly quiet on the highways
The truck bed is huge.
Really like the heads-up display - still think it's magic how it looks like it's a foot in front of the bonnet.
13.4 inch display and really like the option to edit the info on the drivers display like showing gearbox temps etc.
Actually not an awful turning circle - definately better than a 110 landy.
Lots of cameras (including truck bed camera) and can be used while driving (wish car companies would allow the feed to be recorded like Teslas). Also option to install additional cameras on the trailer which integrate into the display.
Still running in, but lots of tourque on tap
Tons of storage areas in the cabin.
Wide enough center console that our dog's bed can comfortably fit there.
6 position tailgate is split and has speaker/lights options along with 110V outlets. (Also has 110V outlets in the cabin too).
Lots of USB & USB-C ports
Keeps a history of trailer settings for different trailers.
Video rear-view mirror - this apparently has a 'transparent' mode so you can see-thru the trailer you are towing.
First 'questionable' Impressions:
It is the size of a box van
Mirrors are massive and actually block vision out the side windows when turning.
Parking is a bit of a mare in tight spaces.
The brake pedal is quite spongy and has a long travel.
You can really really feel the weight when driving.
Not a fan of the retractable foot steps. I think fixed ones look better imo.
Apparently not that difficult to nick, so need to get the USA equivalent of a Ghost fitted.
GMC apps are a bit flaky and only give you 1 month's trial included.
The ride is pretty harsh with the leaf-spring suspension. Road humps have to be taken at a very low speed.
Not specific to this car, but I hate column shifts on vehicles
Regrets?
Yeah I should have ignored warnings about getting a bad back (from the even more harsh ride) and got a dually : )
yellowstreak said:
I love it. What are you towing with this monster? A house? A small ship? A Sherman on a trailer?
lol - just a caravan - just a slightly bigger then normal one something similar to this:https://rv.campingworld.com/rvdetails/used-fifth-w...
Plan is to convert (and tank) the toy space so it can act as a 'stable' for the horse, and seperately we still have living accomodation in the front 2/3rds... I'll probably do a build series on it in a separate thread
catfood12 said:
Looks awesome OP. Pushrod V8? Didn't know they still made such a thing. 975 lb/ft torques. Fantastic. Long live ICE. 
Freedom units.
Keeping the metric system out.
'Merica baby! Freedom units.
Keeping the metric system out. Lol - apparently pushrod is still cutting edge over here which might explain the current 9mpg I'm getting. Frankly the fact it's got disk brakes all round and not drum brakes was a surprise tbh : )
Brother D said:
lol - just a caravan - just a slightly bigger then normal one something similar to this:
https://rv.campingworld.com/rvdetails/used-fifth-w...
Plan is to convert (and tank) the toy space so it can act as a 'stable' for the horse, and seperately we still have living accomodation in the front 2/3rds... I'll probably do a build series on it in a separate thread
ooh sweet! You could also get a motorcycle in maybe!? https://rv.campingworld.com/rvdetails/used-fifth-w...
Plan is to convert (and tank) the toy space so it can act as a 'stable' for the horse, and seperately we still have living accomodation in the front 2/3rds... I'll probably do a build series on it in a separate thread
yellowstreak said:
Brother D said:
lol - just a caravan - just a slightly bigger then normal one something similar to this:
https://rv.campingworld.com/rvdetails/used-fifth-w...
Plan is to convert (and tank) the toy space so it can act as a 'stable' for the horse, and seperately we still have living accomodation in the front 2/3rds... I'll probably do a build series on it in a separate thread
ooh sweet! You could also get a motorcycle in maybe!? https://rv.campingworld.com/rvdetails/used-fifth-w...
Plan is to convert (and tank) the toy space so it can act as a 'stable' for the horse, and seperately we still have living accomodation in the front 2/3rds... I'll probably do a build series on it in a separate thread
- (People do put jeeps in them, but I suspect they could well be over weight in most cases unless it's a stripped down lightweight jeep).
king awesome - absolutely love that 
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