The Chevy Suburban HD Needs GM’s New 6.6L V8 L8T Engine
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General Motors recently announced its all-new 6.6L V8 L8T gasoline engine for the 2020 Chevrolet Silverado HD and 2020 GMC Sierra HD. This immediately made us wonder whether the new motor will make its way under the expansive hood of the new Chevy Silverado Medium Duty. Now, another good candidate comes to mind: the Chevrolet Suburban HD.
Unlike the regular Chevy Suburban, the Suburban 3500 HD is only available to fleet customers, and it’s all about payload, featuring a standard payload capacity of 4,405 pounds and a GVWR (gross vehicle weight rating) of 11,000 pounds. The maximum towing capacity, meanwhile, drops to 3,000 pounds from the regular Suburban’s 8,000-pound towing capacity.
Currently, the Suburban HD is powered exclusively by the 6.0L V8 Vortec L96 gasoline engine paired to GM’s 6L90 6-speed heavy-duty automatic transmission. Notably, the new L8T is the successor to the L96, which also serves as the base engine for the current, K2 platformed Chevy Silverado HD and GMC Sierra HD models, where it is rated at 360 horsepower and 380 pound-feet of torque.
Although capable, the L96 is a relic of an engine, having been around for roughly two decades. The most notable change it received was in the 2009 timeframe, when it got Variable Valve Timing (VVT). It even features Sequential Fuel Injection (SFI), rather than direct injection.
So, if the L8T engine comes to the Suburban HD, then it will likely be only for the next-gen model – which is expected for the 2020 model year (see more on 2020 Suburban). The Suburban HD is naturally a great candidate to get the new engine in addition to the Silverado Medium Duty models. Although we expect the twelfth-gen 2020 Suburban to launch in the fall of this year, it’s unclear whether it will also derive an HD variant this go-round.
About GM’s 6.6L V8 L8T Engine
Based on GM’s fifth-generation Small Block engine architecture, GM’s new 6.6L V-8 L8T gasoline engine is SAE-rated at 401 horsepower and 464 pound-feet of torque in the 2020 Silverado HD and 2020 Sierra HD.
It runs an iron block with aluminum heads, along with direct injection and variable valve timing at a 10.8:1 compression ratio. All that enables it to make robust power low on the power band, which is particularly helpful when it comes to towing.
Stay tuned to GM Authority for more Chevrolet news and Suburban news.
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This assumes, of course, that the next generation Suburban *has* a 2500HD/3500HD variant.
Great idea Michelle. It is possible that GM could retain a Suburban HD model with a solid rear axle and high payload and towing numbers for fleet/government/some retail customers.
All the foreign governments use the 3500 HD version because you can drive them offroad and they won’t break like a regular 1500 Suburban might. By the way, the 3500 pickup trucks for 2020 use a rear 12 inch ring gear while the 2500 versions use an 11.5 inch ring gear. Remember that the towing capacity of the 2020 3500 GM pickup trucks is 35,500 pounds with the 6.6 liter diesel. Now, that would be a real Suburban. Can you imagine, carry 10,000 rounds of bullets and drive through Chicago to go and visit Jussie Smollett in jail…..LOL
Chevy express 4500 cutaway van, used for motorhomes. Would also be a good candidate for the 6.6 L
3k towing is some type a joke! That’s like Cruze territory. Chevy needs to offer a gas and 6.6 Diesel engines with these burbs and give it 12-14k towing numbers, plus drop the the price from 80k to 60k. I know that they want you to buy a truck instead and the only reason why these burbs are made is because of government needs, that also explains why it’s so high in cost. Bureaucracy at its finest.
How about the big boy duramax in the suburban. You have a lot of customers that would purchase one in a heart beat. My dad is still struggling with getting ride of our 05 3/4 ton suburban with the 8.1L Vortec and getting into the new 2020 HD’s though I’m pushing because a new AT4 2500 in the driveway would look nice! ☺️
Search DuraBurb on Youtube
No one believes the new towing capacity of the Suburban HD is accurate. The brakes were enlarged and the rear axle ratio went to 4.10. For true tow ratings I would look up a Silverado HD with the same setup. It matches the 2013 towing numbers at a bare minimum.
I hope they continue the Suburban HD. Otherwise my next vehicle to pull the camper will be a truck with a front bench. That’s not a good way to start a camping trip. Having to take 2 vehicles isn’t ideal either.
Ford Expedition/Max beats in every category.
Let’s see a Burb Diesel with increased towing.
I own a 2018 HD Suburban. It tows my race car on an open trailer (about 6000lbs) with no problems. The only thing I had to add was a trailer brake controller – GM omits this simple fact. The disc brakes are bigger than my size 14 Durango boots! There is no issue with towing, it will tow what an HD pickup will tow. I don’ t understand why GM makes this point so mysterious.
I could see the new 3.0 Inline 6 diesel as a great engine for the Suburban as well.
Why not a Duramax diesel? People are dying to know.
GM needs to man up and bring back the 8.1 but this time do it right – supercharged! My 06 Sub ( may she rest in peace) had the big block 496.
Going camping shouldn’t be the truck pulls the trailer while the wife and kids tag along in a car. That’s why we keep our 99 Suburban. The 7.4L pulls our trailer a whole lot better than our previous truck with the 5.3L. The third row allows the whole family to travel in one vehicle.
We’d like a newer Suburban, but due to smaller engines and limited availability of the 2500/3500 models, we can’t get something new.
I’m in the same position except with the newer 6.0, 6-speed. The 2,000+ lbs payload rating really lets you use the whole truck, every seat AND the hitch receiver. Used HD Suburbans sell fast and the price of the current body style is expensive.
Im gonna be lookin for a 2500 to pull my 30ft rv in the near future, but I’d rather have a Suburban with roof space for bikes/kayaks, but also the tow capacity.
I don’t understand why Chevy does not make it easy to buy a 2500 or 3500 HD suburban, or give us a 3500 Tahoe!
I still am confused on why law enforcement gets these with the 6.6 and we get some tiny 3.0 diesel that has way less torque than a 5.3 gasser. We nee GM to give us the 3500HD suburban with a 6.6 diesel.