GM Duramax Was Head of the Class; Now Not So Much

As part of my guest blogging series for Double Coin Tires, I would like to share my evaluations of the various types of equipment we use. We tow very large and heavy boats up and down the East Coast, so we're talking heavy, wind dragging loads which cause our trucks to really WORK!

Concerning our tires and wheels, all of our trucks utilize the lowest lift to clear --
255/70/22.5 RLB1 Double Coin tires and American Force wheels. Absolutely no complaints there, but what about the rest of our equipment? In this blog post, I want to share my experiences with the GM Duramax engine.

The Duramax
I have run almost every year model GMC/Chevrolet 3500/4500 truck which comes with a Duramax engine. The Duramax engine was the greatest technological advance in diesels on its introduction; however, GM has allowed other manufacturers to not only catch up but to surpass this design.

The Duramax engine can make as much power as you can possibly want or need, but when working this motor day in and day out we run into the issue of heat. The motor simply doesn't have sufficient cooling for the hot and heavy tow market.

Concerning the CEL (check engine light), when the Duramax sees a fuel issue it will trigger P0087 that will create a limp mode. When empty you can move at slow speeds to get off the highway, When loaded, however, you are dead in the water! The truck will leave you stranded unless you unhook from the trailer.

Regarding the exhaust brake added in 2010, this addition performs great when having to stop heavy loads. However it's not quite as strong as the exhaust brake on the c4500 versions in previous years.

The Allison transmission has never failed me in any of my Duramax trucks, so I have absolutely no issue with this transmission and would give it a 10. The transmission has an adaptive TCM which learns the way you drive the truck to be able to perform the smoothest shifts under your normal driving parameters.

The suspension on a Duramax is still an independent front end, which under my test with 22.5's is far less reliable than the competition. This design must be lifted 6" to safely clear the size wheel and tire. Yes you can destroy the front end with a set of keys or messing with the torsion bars. However you will end up losing a ball joint and possibly lose control at highway speeds which is extremely dangerous. This is by far the most ignorant and dangerous lifting solution you could ever try. The ride from this style suspension is absolutely great; however in the heavy tow world, it's much less reliable. The independent front end should be left to the Escalade.

Brakes in the Duramax have always been squishy.  I'm not sure what causes this but I have been told by many people that this is just a Duramax pedal. Needs to be upgraded BAD.

The Duramax cab has always been one of the most comfortable designs of any truck on the market. GM has always been cutting edge when it comes to interior advancements. I would like the dash to be the same design as the new Denali SUV but it's still well designed in my opinion.

The rear end options in the Duramax have always been a 3:73 which are not sufficient in the tow world; a 4:10 is severely needed.

Since GM boxed the frame in 2010, the frame handles towing heavy loads much better than previous models.

On the GM trucks, the DEF system is still located under the hood which is quite possibly the worst design ever! When towing you must frequently refill the def tank, which at the large truck pumps is almost impossible since the def pump is located beside the fuel pump on the driver's side. On a zero to 10 scale this design is a strong Zero!

My overall rating for the Duramax as a work horse in the tow world would be a 6.

As I stated at the beginning, I am completely satisifed with my Double Coin tires, and I encourage you to go to their website to find your local Double Coin dealer.

Also, why not try your luck in the Double Coin Smart Money Tire Drawing to win a set of 4 drive tires valued at up to $1,200? The drawing will be held soon so click on the banner below to enter. It only takes a few seconds!