2020 Freightliner vs 3500 GMC Dually at the Ike

[FishOnOne]

Interesting outcome...

Trailer: 18,500 lbs

GMC
Engine: 6.6 Duramax
Brake Applications: 1
Time: 10:28

Freightliner
Engine: 9.0 Cummins
Brake Applications: 0
Time: 10:42

Link

[4x4ord]

Bionic Man wrote:
So, what is the best way to lower EGTs?

There is basically three ways that I know of to lower the EGT. Less fuel, more air (more boost) or by aftercooling. I suppose a 4th way is to do what Chevy has done and add a hood scoop to draw cooler air into the air intake.

[Cummins12V98]

allen8106 wrote:
A horse trailer advertisement disguised as a downhill towing comparison. JMHO.

True DAT!

[allen8106]

A horse trailer advertisement disguised as a downhill towing comparison. JMHO.

[gmw_photos]

We participate at least one national level horse show per year and usually two, and generally at one world level show. The overwhelming majority of tow vehicles are 3500 dualies, even at these higher level shows.

There will always be a few class eight trucks, and a handful of medium duty. The other several hundred is almost all one ton dually.

Obviously a one ton dually is also a good daily use vehicle running solo, where a MDT, a little less so desirable.

The F-liner is nice, and I'd like to have one, but it's really just not needed for what we do.

[larry_barnhart]

We see freightliners towing similar horse trailers going on I-10 because of lots of horse action in Az but the rv towing not really or as it used to be. Driving on I-90 yesterday and same look but smaller horse trailer with a 3500 GMC passed us. maybe a $100K model.
all trucks are awesome now.

chevman

[Cummins12V98]

"The Freightliner has a wire mesh front grill that looks like a winter grill but it's not. Go to 11:37 to get a close view."

Thanks!

[ls1mike]

I don't care about the results either way. I am taking the Freightliner all day long. It looks pretty comfortable and you can never be over trucked. 🙂

163,000 dollar trailer. Did you guys catch that? I pooped a little.

[ShinerBock]

4x4ord wrote:

Me Again wrote:

4x4ord wrote:
^^^^ Maybe. Anything I have driven with an engine brake had position 1 2 or 3 and was either off or on. No modulating.

Lots of RPMs left to be in 3rd and hold back a much larger load at 50MPH.

I don't know where the redline is on the 9l. On a larger diesel engine I wouldn't want to see it rev much over 2100 rpm. The loads I tow I seldom see the jake operating above 1800 rpm. If the Allison behind that 9l dropped to 3rd the engine would rev to 2800 rpm which might be ok?

The max rpm of the ISL (or L9 now) varies depending on application from 1,900-2,200 rpm. Most on highway high horsepower applications are governed at 2,200 rpm.

[rjstractor]

4x4ord wrote:
The GM was not putting out anywhere near its advertised HP. A truck equipped with an engine making 445 hp / 910 lb ft would have been able to make that run in very close to 7 minutes 20 seconds. I think the high altitude must drastically affect the power these engines are able to make. If the Cummins was producing the power it is advertised to make it should have made the run in just over 9 minutes.

That's the thing I like about the Ike Gauntlet tests. The tests show time after time that the manufacturers rating numbers are just one factor that determines how fast a truck goes up the hill. If the question had been asked "which truck gets up the hill faster", the 350 hp Freightliner or the 445 hp GM towing the same weight, the overwhelming response from the "numbers" guys would have been the GM would have smoked the Freightliner, which it did not. The Ike test proves that sometimes those numbers are just numbers.

[4x4ord]

Me Again wrote:

4x4ord wrote:
^^^^ Maybe. Anything I have driven with an engine brake had position 1 2 or 3 and was either off or on. No modulating.

Lots of RPMs left to be in 3rd and hold back a much larger load at 50MPH.

I don't know where the redline is on the 9l. On a larger diesel engine I wouldn't want to see it rev much over 2100 rpm. The loads I tow I seldom see the jake operating above 1800 rpm. If the Allison behind that 9l dropped to 3rd the engine would rev to 2800 rpm which might be ok?

[FishOnOne]

Cummins12V98 wrote:
They mentioned it was hot that day so why was the winter front on the M2?

Why use an older GMC for the test?

The Freightliner has a wire mesh front grill that looks like a winter grill but it's not. Go to 11:37 to get a close view.

Both trucks were provided by Transwest so they used what they got. Also the GMC has the L5P Duramax so its essentially the same engine as todays trucks.

[Me_Again]

4x4ord wrote:
^^^^ Maybe. Anything I have driven with an engine brake had position 1 2 or 3 and was either off or on. No modulating.

Lots of RPMs left to be in 3rd and hold back a much larger load at 50MPH.

[4x4ord]

^^^^ Maybe. Anything I have driven with an engine brake had position 1 2 or 3 and was either off or on. No modulating.

[Me_Again]

4x4ord wrote:

Me Again wrote:

4x4ord wrote:
They praise the performance of the engine brake on the Freightliner over the performance of the exhaust brake on the GMC, however, if more weight had been loaded into the trailer the Duramax would have held 50 mph yet the Freightliner would have required additional brake applications. Comparing two trucks on one hill with only one weight in tow doesn't really offer an honest comparison. I'm having trouble understanding why the GM slowed down as much as it did going up the hill ..... something doesn't add up. Even back in 2015 (with 396 HP and 765 lb ft) the Duramax towed 19000 lbs up the Ike in just under 10 minutes. link

I don't think your statement on the Freightliner is correct. The cruise control was holding it at 50 MPH, most likely had a lot more anchor chain in the chain locker. RAM has this feature also when the EB is in auto. I do not use it because it does not brake until about 3-4 MPH above the CC speed.

I think the new GMs likely adjust the exhaust brake in auto as does the Ram and Ford. I believe in the test they had the GM exhaust brake turned to "on" which makes me think auto wasn't available in 2017. With the Freightliner Mr Truck said he didn"t have the cruise set. He said the engine brake could be set at 3 or 6 and he had it set at 6. So the Cummins was braking all it could without downshifting.

I looked at it again, and yes he did say that he was not on CC. My bad! He did however say that the engine brake was holding the truck in 4 gear or lower and holding the 50 MPH speed, so it had to be modulating the engine brake to maintain 50 MPH as the grade changes.