Duramax power climbing grade?

[harleybiker]

I purchased a Chevy 3500hd Diesel recently. I was wondering what to expect while climbing a 6% grade at 60 MPH towing a 12,000 lb Fifth Wheel. Will it accelerate if floored? Thanks.

[Ray,IN]

That depends upon you! There are several things vital to properly maintaining a Duramax, the first is only buying clean diesel fuel from a station with high sales volume, second is changing the fuel filter regularly per maintenance schedule in owners manual. Visit the irv2.com duramax forum to learn from other owners.

duramaxforum.com and duramaxdiesels.com are also good resources.

[uncledon]

I have an '02 6.6 LB7 that I've owned since 16k miles. Now just clicked over 160k. I have a larger rig now, and this spring I added the Banks Power Pack and an exhaust brake. I used to haul a Wildcat fiver with it that was right in your weight range. I pulled it through the Appalachians a few times and it held its own fine. On steep grades with the stock shift pattern I was not impressed with performance, thus the upgrade tuner. I would stomp the accelerator and force the downshift, then she would pick up her pace.

Newer trucks are going to be different.

[Soppy]

I doubt it would accelerate from 60 MPH. A lot depends on the gear ratio , tire size , temperature , vehicle weight, wind , etc. You would be pushing the engine to the max and as the engine temperature increases , it will start to de fuel to keep the engine from "melting down" .

[DucBill]

Depends on year and maintenance as mentioned previously FWIW I have '15 GMC 3500 SLT DADC DRW that pulls a '14 Keystone Fuzion 375 which weighs in at 15.5K#s I live in So Cal so I'm surrounded by Mtns I regularly tow up and down I 15 Cajun pass which is 6% grade for about 8 miles also including Big Bear Mtn which,has 8500' pass on Hwy 38 and have towed up US 395 to Mammoth and Tahoe which have grades in excess of 6% at elevations up to 8500'. My GMC which is stock except I1.8 Banks gauge. Climbs at 62mph and when needed can go faster when slow semis are passing @ 35mph but mpg is 3-4 . My previous '05 Chevy Siverado 2500 LT DACC would struggle and overheat when pushed hard pulling a KZ New Vision 37 weighing approx 14k#s usually when climbing to Kennedy Mdws 8k' in Sierras on the notorius 9 mile grade from 2k' - 6k' @ 25 mph. I added a Banks Otto Mind power pack including a Speed Brake, HD Torq converter, CAI with below bumper scoop which dropped CAC air temp significantly but the best upgrd IMHO was the AFE turbo inlet mouthpiece which opened intake track to match the turbo inlet area. With the above mods the Chevy power increased significantly and temps became managable. YMMV

[WETHREE]

I regularly go over 10k passes with my 2016 2500 CC short bed pulling a 33’ 5th wheel with no problems. Of course most are not straight roads, switch backs etc in Colorado. Power is never an issue but going downhill is what’s amazing with tow haul/jake brake and the magic of the Allison transmission. Just keep your pin weight and truck load in specs and you can pull anything.

[V3600]

Yes, it will accelerate. Mine does and I'm towing about 3 more tons than you.

[redhooker]

I will second the yes. I also run a LML and have pulled 16k up 7%. It will accelerate over 60 but was approaching trans temps near 200 with ambient above 90. I was able to hold 65 without struggle but did not attempt to push any harder as I do not have an egt gauge.

[coloelk52]

I live at the bottom of Wolf Creek pass and so have to go over it whenever traveling east. In stock form my lml would pull 16K over it with ease including the ability to accelerate on the grade. Better still is the exhaust brake coming down.

[KD4UPL]

What year truck are we talking about? The power varies widely from an '01 truck to a new one. '01 had about 300 HP and 520 lb/ft. A new 2018 has 445 HP and 910 lb/ft.

[K_n_L]

I've pulled our toyhauler, figure about 15K loaded, with our 2015 Chevy across West Virginia , North Carolina Smokeys and over Powder River Pass in Wyoming at 10K elevation and never felt under powered. I've only had it floored a couple of times if I lost momentum behind a semi where I couldnt get over. The newer version and other brands might edge the LML on it numbers, but its done everything we've needed it to.

[coloelk52]

2011 lml

[Roadglide54]

I traded off 13 lml gvw 23000 on2500 excellent towing vehicle. My18 L5P 3500 tows the same 23kgvw .the 3500has more power and bigger yellow tag .the 2500 did just as good for stopping and towing as the L5P.